CHENGDU, China, July 30, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that a new indication application of its trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®) has been accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China, for the first-line treatment of patients with recurrent or metastatic triple-negative breast cancer (TNBC) who have a programmed death ligand 1 (PD-L1) combined positive score (CPS) <10, or have recurred after prior programmed cell death protein 1 (PD-1)/PD-L1 inhibitor therapy in the early stage. This marks the sixth indication application accepted by the NMPA for sac-TMT.

The acceptance for review is based on the positive results from the randomized, open-label, multicenter Phase III registrational OptiTROP-Breast03 study evaluating the efficacy and safety of sac-TMT versus investigator's choice of chemotherapy in patients with unresectable recurrent or metastatic TNBC who have not received prior systemic therapy for advanced disease. The enrolled population included patients with PD-L1 CPS <10, as well as those who have recurred after prior PD-1/PD-L1 inhibitor therapy in the early stage. The study demonstrated that sac-TMT achieved statistically significant and clinically meaningful improvements in key efficacy profile compared with investigator's choice of chemotherapy, showing a clear clinical benefit.

Previously, sac-TMT was granted Breakthrough Therapy Designation (BTD) by the NMPA for the first-line treatment of unresectable locally advanced, recurrent or metastatic PD-L1-negative TNBC. This new indication application has also been included in the priority review and approval process, becoming the sixth application for sac-TMT to enter this process. Inclusion in this process is expected to further expedite the review and approval, allowing this innovative treatment to benefit patients sooner. 

Dr. Michael Ge, CEO of Kelun-Biotech, said, "Following the approval of sac-TMT for second-line or later treatment of TNBC based on results from the Phase III OptiTROP-Breast01 study, we are delighted to see another important milestone in the same disease area. For patients with PD-L1-negative advanced TNBC, the efficacy of traditional chemotherapy is limited, and there is an urgent clinical need for more effective and safer first-line treatment options. The positive results from the OptiTROP-Breast03 study demonstrate a clear and clinically meaningful improvement in efficacy with sac-TMT compared to chemotherapy and support the continued evaluation of sac-TMT as the first-line treatment for TNBC. We look forward to the early approval of this indication to bring a new and more effective first‑line treatment option to a broader population with advanced TNBC."

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as non-small cell lung cancer (NSCLC), breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six BTDs by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer.  Two new indication applications have been accepted for review by the NMPA and have been included in the priority review and approval process: 1)  sac-TMT in combination with pembrolizumab (KEYTRUDA^®[1]) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 tumor proportion score (TPS)≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative; and 2) sac‑TMT as first‑line treatment for patients with recurrent or metastatic TNBC who have a PD‑L1 CPS <10 or have recurred after prior PD‑1/PD‑L1 inhibitor therapy in the early stage. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD has initiated 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 2 projects with 3 indications are in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, July 27, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) today announced that it has received a clinical trial notice from the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) approving the Investigational New Drug (IND) application for its novel dual-payload ADC drug, SKB565, for the treatment of advanced solid tumors. This marks the Company's first dual-payload ADC to enter the clinical stage.

SKB565 is developed using the Company's proprietary OptiDC™ platform. Featuring an innovative dual-payload design, SKB565 enables the direct delivery of toxins and immunomodulators, two kinds of payload with complementary mechanisms of action, to tumor tissue. Compared with conventional ADCs carrying only toxins, SKB565 has a dual antitumor mechanism: it precisely targets and kills tumors while activating the immune system within the tumor microenvironment to elicit an antitumor immune response, bringing enhanced and more durable antitumor efficacy. In preclinical studies, SKB565 demonstrated excellent antitumor activity and safety, with its outstanding therapeutic potential to support further clinical development.

Leveraging technological expertise and platform advantages in the ADC field, Kelun-Biotech has established a diversified pipeline of innovative molecules featuring high-value targets, differentiated designs, and global potential. Building on this foundation, the Company continues to advance its "ADC + IO" strategy—on one hand by actively exploring high-quality combination regimens, including multiple ongoing clinical studies evaluating ADCs in combination with PD-(L)1 monoclonal antibodies, as well as the PD-1/VEGF bispecific antibody SKB118 in combination with its proprietary ADC portfolio; on the other hand, the Company is advancing integrated drug design strategies by incorporating synergistic functional components into a single ADC molecule.

Dr. Michael Ge, CEO of Kelun-Biotech, said, " SKB565 is one of the core representative drugs of our integrated 'ADC + IO' strategy, leveraging the synergistic mechanism of its dual payloads to enhance efficacy and overcome drug resistance. Dual-payload ADCs are emerging as one of the key next-generation innovations in the ADC field. The advancement of SKB565 into clinical stage not only marks an important milestone in the achievements transformation of our technology platform, but also substantiates the continued deepening of our innovation capabilities in ADCs. We will actively advance the clinical development of novel drug conjugates such as SKB565, striving to deliver greater benefits to patients with cancer as soon as possible."

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, July 15, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) and Harbour BioMed (HKEX: 02142) today announced that the National Medical Products Administration (NMPA) of China has approved the Investigational New Drug (IND) application for SKB575/HBM7575, a long-acting bispecific antibody targeting thymic stromal lymphopoietin (TSLP) and an undisclosed target co-developed by the two parties, for the treatment of asthma. Previously, the first participant has been dosed in a Phase I clinical study of SKB575/HBM7575 for the treatment of atopic dermatitis.

Asthma is a chronic respiratory condition affecting approximately 300 million people worldwide, with prevalence continuing to rise. Despite the availability of treatment options, many patients experience persistent symptoms, frequent exacerbations, and reduced quality of life. Current therapies - mainly inhaled corticosteroids (ICS) and bronchodilators - are inadequate for some patients, underscoring the urgent need for more effective, long-acting treatments that address the underlying disease mechanisms.

Dr. Michael Ge, CEO of Kelun-Biotech, stated: "With the company's active efforts, SKB575/HBM7575 has initiated clinical trials for two chronic immune‑mediated diseases, atopic dermatitis and asthma. As a differentially designed and engineered bispecific antibody, SKB575/HBM7575 is expected to achieve potent inflammation control and broad patient coverage through its dual-target synergistic mechanism, whilst offering convenient administration. We will vigorously advance the development of this drug to fully realize its clinical value." 

About SKB575/HBM7575
SKB575/HBM7575 is a long-acting bispecific antibody targeting TSLP and an undisclosed antigen, with a dual mechanism of action. On one hand, by blocking the interaction between TSLP and its receptor, it inhibits TSLP-mediated signaling pathways and the activation of Th2 immune cells. On the other hand, binding to and blocking the undisclosed target generates a synergistic effect, with the potential to achieve broader control of inflammation compared to single-target approaches. SKB575/HBM7575 has been engineered to allow for longer dosing intervals and a convenient subcutaneous route of administration. Based on preclinical half-life data, the anticipated human half-life is expected to support dosing intervals of more than three months, positioning it as a potential best-in-class therapy.

According to the collaboration agreement between the Company and Harbour BioMed, SKB575/HBM7575 is led by Kelun-Biotech in its design, global development and commercialization, with Harbour BioMed participating in the investment and development of this asset and sharing the benefits as agreed.

About Kelun-Biotech
Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

About Harbour BioMed
Harbour BioMed (HKEX: 02142) is a global biopharmaceutical company committed to the discovery and development of novel antibody therapeutics in immunology and oncology. The company is building a robust and differentiated pipeline through internal R&D capabilities, strategic global collaborations in co-discovery and co-development, and selective acquisitions.

Harbour BioMed's proprietary antibody technology platform, Harbour Mice^®, generates fully human monoclonal antibodies in both the conventional two heavy and two light chain (H2L2) format and the heavy chain-only (HCAb) format. Building upon HCAb antibodies, the HCAb-based immune cell engagers (HBICE^®) bispecific antibody technology enables tumor-killing effects that traditional combination therapies cannot achieve. Additionally, the HCAb-based bispecific immune cell antagonist (HBICA^TM) technology empowers the development of innovative biologics for immunological and inflammatory diseases. By integrating Harbour Mice^®, HBICE^®, and HBICA^TM with a single B-cell cloning platform, Harbour BioMed has built a highly efficient and distinctive antibody discovery engine for developing next-generation therapeutic antibodies. For more information, please visit http://www.harbourbiomed.com/.

• As a head-to-head Phase III trial comparing sac-TMT plus pembrolizumab with the first-line standard of care (immunotherapy plus chemotherapy), OptiTROP-Lung06 demonstrated the superiority of replacing conventional pemetrexed/platinum chemotherapy with sac-TMT, with significantly prolonged PFS and a positive OS trend compared with pembrolizumab plus pemetrexed and platinum-based chemotherapy.
• Focusing on the particularly challenging first-line treatment for PD-L1-negative non-squamous NSCLC population, the introduction of a TROP2 ADC to a PD-1 mAb not only delivers ADC's precise targeting and killing of tumor cells, but also activates the immune microenvironment through their synergetic mechanisms. This strategy is expected to unlock the therapeutic potential of the PD-1 mAb in patients with PD-L1-negative or limited immune responses, breaking this therapeutic bottleneck.
• Following the meeting of the primary endpoint in the Phase III OptiTROP-Lung05 study for first-line PD-L1-positive NSCLC, the positive results were achieved in another Phase III trial of sac-TMT plus pembrolizumab, providing robust clinical evidence supporting the expansion of this combination regimen to a broader first-line NSCLC population.

CHENGDU, China, July 15, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced today that the Independent Data Monitoring Committee (IDMC) concluded that the Phase III clinical study (OptiTROP-Lung06) of its trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®), in combination with MSD's^[1] anti-programmed cell death protein 1 (PD-1) therapy KEYTRUDA^®[2] (pembrolizumab) as a first-line treatment for programmed death-ligand 1 (PD-L1)-negative locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) has met its primary endpoint of progression‑free survival (PFS) at a prespecified interim analysis. This is the world's first Phase III clinical study of an ADC combined with an immune checkpoint inhibitor to meet its primary endpoint in the first-line treatment of driver gene‑negative and PD‑L1‑negative non-squamous NSCLC.

OptiTROP-Lung06 is a randomized, open‑label, multicenter Phase III clinical study evaluating the efficacy and safety of sac-TMT in combination with pembrolizumab versus chemotherapy in combination with pembrolizumab as first-line treatment for patients with locally advanced or metastatic non-squamous NSCLC who have PD-L1 tumor proportion score (TPS) <1%. The primary endpoint of the study was PFS assessed by blinded independent central review (BICR); secondary endpoints included overall survival (OS), safety and others. At a pre-specified interim analysis, the sac-TMT combined with pembrolizumab demonstrated a statistically significant and clinically meaningful improvement in PFS compared with pembrolizumab combined with pemetrexed and platinum-based chemotherapy, and a positive trend in OS was also observed. The safety profile of sac-TMT combined with pembrolizumab was consistent with that observed in previously reported studies, and no new safety signals were observed. The Company plans to communicate with the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China based on the results of this sac‑TMT study.

Previously, the Phase III registrational OptiTROP-Lung05 study of sac-TMT in combination with pembrolizumab as first-line treatment for PD-L1-positive NSCLC had successfully met its primary endpoint, supporting the submission of a new indication application to the CDE. The findings of the OptiTROP-Lung05 study were presented as an oral report at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting and simultaneously published in The Lancet. The positive results from the OptiTROP-Lung06 study mark the further expansion of sac-TMT plus immunotherapy into the PD-L1-negative population in first-line non-squamous NSCLC, providing clinical support for this combination strategy to cover a broader first-line NSCLC population and are expected to drive the optimization of first-line treatment landscape for driver gene-negative non-squamous NSCLC.

Professor Caicun Zhou, National Lead Principal Investigator from Shanghai East Hospital, Tongji University, said: "For patients with driver gene‑negative and PD‑L1‑negative NSCLC, immunotherapy combined with chemotherapy remains the current standard first-line treatment and has improved patient outcomes to some extent. However, long-term survival benefit remains limited. The achievement of positive results in the Phase III OptiTROP-Lung06 study represents an important breakthrough in the first-line treatment of PD-L1-negative NSCLC. These results not only provide robust clinical evidence supporting the 'ADC plus immunotherapy' strategy of sac-TMT in combination with pembrolizumab, but also have the potential to offer these patients a new first-line treatment option beyond the current standard of care, with the promise of improved survival outcomes."

Dr. Michael GE, CEO of Kelun-Biotech, stated: "We are delighted to see that sac-TMT combined with pembrolizumab has achieved exciting positive results compared with immunotherapy plus chemotherapy in the first-line treatment of patients with PD-L1-negative NSCLC. This ADC plus immunotherapy regimen has previously demonstrated superior efficacy over immunotherapy monotherapy in patients with PD-L1-positive NSCLC. The positive results of both the OptiTROP-Lung05 and OptiTROP-Lung06 studies confirm the strong synergetic effect of sac-TMT combined with pembrolizumab, supporting the potential of this combination regimen to benefit the broad first-line NSCLC population and bringing new treatment opportunities to patients with different PD-L1 expression levels."

Sac-TMT is currently being evaluated in ten registrational studies in lung cancer, including five registrational studies in China and five global multicenter Phase III studies.

About sac-TMT(佳泰莱^®)
Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD has initiated 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech
Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

— The study shows that EGFR-TKIs induce TROP2 upregulation in DTP cells, providing a mechanistic basis for combining sac-TMT with EGFR-TKI.

— The Company is conducting a Phase III registrational study of sac-TMT plus osimertinib as first-line treatment for advanced EGFR-mutant NSCLC (enrollment completed; follow‑up phase) and a Phase II study of the same combination as neoadjuvant treatment for EGFR-mutant resectable NSCLC.

— Sac-TMT has been approved in China for advanced EGFR-mutant NSCLC following progression on TKI therapy or TKI therapy and platinum-based chemotherapy, and has demonstrated significant PFS and OS benefits in TKI-resistant settings.

CHENGDU, China, June 22, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company") announced that translational research results on its sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870)(佳泰莱^®) in combination with osimertinib as first-line treatment for advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) have been published online in Cancer Cell, an international academic journal.

The paper, titled "Targeting TROP2 in drug-tolerant persister cells delays EGFR tyrosine kinase inhibitor resistance in non-small-cell lung cancer," was led by Professor Li Zhang and Professor Wenfeng Fang from the Sun Yat-sen University Cancer Center. The study shows that trophoblast cell-surface antigen 2 (TROP2) expression is upregulated in residual drug-tolerant persister (DTP) cells after EGFR tyrosine kinase inhibitor (TKI) treatment; in preclinical models, sac-TMT combined with osimertinib inhibited DTP cell formation and delayed tumor recurrence. These findings provide translational medicine evidence for the combination of TROP2-directed antibody drug conjugate (ADC) and EGFR‑TKI in delaying drug resistance, and further underscore the differentiated value of sac-TMT as a key combination partner for EGFR-TKIs.

Building on the above research and clinical development plans, the Company is advancing a Phase III registrational study (NCT06670196) of sac-TMT in combination with osimertinib versus osimertinib monotherapy as first-line treatment for locally advanced or metastatic EGFR-mutant non-squamous NSCLC. The study is designed to evaluate the efficacy and safety of sac-TMT (4 mg/kg, Q2W) plus osimertinib compared with osimertinib monotherapy in this indication. Patient enrollment in China has been completed, and the study is currently in the follow-up and data maturity phase.

In addition, the Company is advancing clinical exploration of sac-TMT for earlier-stage EGFR-mutant NSCLC. A Phase II study (NCT07329322) is ongoing to evaluate sac-TMT in combination with osimertinib or as monotherapy in the neoadjuvant setting for EGFR-mutant resectable NSCLC, further exploring the potential value of sac-TMT in perioperative treatment.

This publication in Cancer Cell reinforces the scientific foundation for combining sac-TMT with EGFR-TKIs as first-line treatment for EGFR-mutant NSCLC. The Company will continue to explore the potential of this combination regimen in earlier-line treatment, resistance delay, and long-term benefit, building on the approved indications and clinical development plan of sac-TMT in EGFR-mutant NSCLC. Kelun-Biotech remains committed to driving innovation in treatment paradigms for EGFR-mutant NSCLC and expanding therapeutic options for patients.

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the National Medical Products Administration (NMPA).

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®[1]) as first‑line treatment for locally advanced or metastatic NSCLC who have programmed death ligand 1 (PD-L1) tumor proportion score (TPS)≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.  

• COPD study initiation expands SKB378/WIN378 development into a second major respiratory disease
• SKB378/WIN378 is currently being evaluated in the Phase 2/3 POLARIS asthma study, with initial Phase 2 data expected in the second half of 2026
• SKB378/WIN378 has the potential to be the first-to-market, ultra long-acting anti-TSLP antibody for asthma and COPD, with Phase 3 initiation in asthma planned for Q4 2026

CHENGDU, China, June 9, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company") today announced that its partner Windward Bio has dosed the first patients in the Phase 2 SIRIUS study of SKB378/WIN378 (also known as HBM9378) in patients with chronic obstructive pulmonary disease (COPD).

COPD is a progressive, irreversible lung disease and the third leading cause of death worldwide. Driven by immune-mediated airway inflammation and persistent airflow obstruction, the disease makes even routine daily activities a struggle. Its defining feature is exacerbations — sudden, severe flare-ups that lead to emergency room visits, hospitalizations, and lasting declines in lung function. Despite currently available inhaled background therapies, more than 3 million patients with moderate-to-severe COPD remain at high risk of recurrent exacerbations, underscoring an urgent need for better treatment options.

SIRIUS is a global, Phase 2 randomized, double-blind, placebo-controlled, dose-finding study. It is designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of SKB378/WIN378 in patients with moderate-to-severe COPD.

SKB378/WIN378 started as a co-development project jointly conducted by the Company and Harbour BioMed, with both parties equally sharing global rights.

About SKB378/WIN378 (also known as HBM9378)

SKB378/WIN378 is a next-generation, fully human monoclonal antibody that potently inhibits the TSLP ligand. This clinically validated target plays a key role in the development and progression of a wide array of immunological diseases, including asthma and COPD. SKB378/WIN378 has been engineered to achieve half-life extension (HLE) and silenced effector function. It has been studied in a Phase 1 trial, which confirmed an extended half-life suitable for twice-yearly dosing, demonstrated a low rate of antidrug antibodies, and was safe and well tolerated up to the highest dose tested. SKB378/WIN378 is administered subcutaneously. Windward Bio licensed the global rights (excluding Greater China and several Southeast and West Asian countries) for SKB378/WIN378 from Kelun-Biotech and Harbour BioMed (also known as HBM9378). WIN378 is currently being evaluated in the POLARIS Phase 2/3 asthma study with initial readouts expected in the second half of 2026. WIN378 is also being evaluated in the SIRIUS Phase 2 COPD study. The first Phase 3 study of WIN378 in asthma is expected to begin in the fourth quarter of 2026.

About Kelun-Biotech 

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/. 

About Windward Bio

Windward Bio is a clinical-stage biotechnology company with deep discovery, development, and commercialization expertise committed to transforming the treatment of people living with serious immunological conditions. Its lead program is WIN378, a potential best-in-disease, ultra long-acting anti-TSLP monoclonal antibody currently in a Phase 2/3 trial for asthma and in a Phase 2 study for COPD. The pipeline also includes WIN027, a clinical-stage, long-acting anti-TSLPxIL-13 bispecific with broad therapeutic potential across immunological diseases, which is currently in Phase 1. The company is building a discovery pipeline of long-acting bispecific antibodies, targeting validated biology in respiratory and dermatological conditions.

CHENGDU, China, June 3, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting held in Chicago, USA, the first-in-human study results of the novel B7-H3 ADC SKB500 in patients with advanced solid tumors were presented as a rapid oral report by Professor Liu Haifeng from Jilin Provincial Cancer Hospital (Abstract #3011|Molecularly Targeted Agents and Tumor Biology).

SKB500 utilizes an antibody with high affinity, high hydrophilicity, and enhanced endocytosis, and has been engineered to silence Fc effector function in the constant region. Moreover, the antibody is conjugated to a payload with moderate toxicity via a cleavable hydrophilic AAA linker, with a drug-to-antibody ratio (DAR) of approximately 8.

The study was divided into three stages: dose escalation, dose expansion, and indication expansion, enrolling a total of 192 patients, including those with small cell lung cancer (SCLC), esophageal squamous cell carcinoma (ESCC), head and neck squamous cell carcinoma (HNSCC), colorectal cancer (CRC), neuroendocrine carcinoma (NEC), and other tumors. Patients received SKB500 at doses ranging from 2 to 18 mg/kg every three weeks (Q3W), with dose expansion and indication expansion conducted at 12 mg/kg and 16 mg/kg.

As of March 31, 2026, efficacy data showed:

• Antitumor activities were observed across multiple solid tumor types, including SCLC, ESCC, HNSCC, pancreatic ductal adenocarcinoma (PDAC), non-small cell lung cancer (NSCLC), and nasopharyngeal carcinoma (NPC). Among 124 patients treated at 12 mg/kg with at least 6 weeks of follow-up, the objective response rate (ORR) was 42.7%, and the disease control rate (DCR) was 83.9%.
• Among the treated SCLC patients (n=40), the ORR was 65.0% (95% CI: 48.3, 79.4), median progression-free survival (mPFS) was 7.2 months (95% CI: 4.3, NE), DCR was 95.0%, and mDOR was 5.8 months.
• Among the treated ESCC patients (n=37), the ORR was 54.1%.

In terms of safety, compared to the 16 mg/kg group, the 12 mg/kg group demonstrated a more favorable safety profile, characterized by a lower incidence of grade ≥3 treatment-related adverse events (TRAEs) and treatment-related serious adverse events (TRSAEs), as well as a low rate of permanent discontinuation. In the 12 mg/kg group, the incidence of grade ≥3 TRAEs was 32.3%, most commonly hematologic events.

The study demonstrates that SKB500 exhibits broad-spectrum antitumor activity, with responses observed in multiple treated advanced solid tumors including SCLC, ESCC, HNSCC, and PDAC, with notable efficacy in SCLC patients. At the 12 mg/kg group, SKB500 showed a favorable safety profile, where there was a low incidence of permanent discontinuation and no treatment-related deaths.

Professor Liu Haifeng, Principal Investigator from Jilin Provincial Cancer Hospital, said: "The positive results from this first-in-human study of SKB500 not only preliminarily confirm its favorable efficacy and manageable safety profile as a novel B7-H3 ADC, but also suggest its therapeutic potential in multiple solid tumors—offering particular hope for SCLC, a disease that is highly aggressive and has limited later-line treatment options. These findings lay a solid foundation for further clinical development. We look forward to further validating its clinical value in subsequent trials."

About SKB500

SKB500 is a novel B7-H3-targeted ADC independently developed by the company using its OptiDC™ platform technology, featuring a site-specific cleavable linker and a potent topoisomerase I inhibitor. In the Phase I clinical study, SKB500 demonstrated robust efficacy and manageable safety profiles across multiple advanced solid tumors. Currently, a Phase II exploratory study of SKB500 in combination with immunotherapy with or without chemotherapy as first-line treatment for extensive-stage small cell lung cancer (ES-SCLC) is ongoing in China.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, May 31, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company", 6990.HK) announced today that the results of the Phase III clinical study OptiTROP-Lung05, evaluating the company's trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870)(佳泰莱^®) in combination with pembrolizumab (KEYTRUDA^®[1], MSD's anti-programmed cell death protein 1 (PD-1) antibody) as first-line treatment for Programmed Death-Ligand 1 (PD-L1) Tumor Proportion Score (TPS)≥1% non-small cell lung cancer (NSCLC), have been published in the prestigious international medical journal The Lancet (IF=88.5)^[2]. The co-senior authors are: Professor Caicun Zhou from Shanghai East Hospital, Tongji University; and Dr. Junyou Ge, Director of the National Engineering Research Centre of Targeted Biologics. The co‑first authors are: Professor Anwen Xiong from Shanghai East Hospital, Tongji University; Professor Wenxiu Yao from Sichuan Cancer Hospital; Professor Wei Zheng from Shengjing Hospital, China Medical University; Professor Yan Yu from Harbin Medical University Cancer Hospital; Professor Peng Chen from Tianjin Medical University Cancer Institute and Hospital; Professor Hua Zhong from Shanghai Chest Hospital; and Dr. Junyou Ge, Director of the National Engineering Research Centre of Targeted Biologics. The study findings were also selected for an oral presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract #8506, Lung Cancer – Metastatic Non-Small Cell).

OptiTROP-Lung05 is a randomized, open-label, multicenter Phase III clinical study designed to evaluate the efficacy and safety of sac-TMT in combination with pembrolizumab versus pembrolizumab alone as first-line treatment for patients with locally advanced or metastatic PD-L1 TPS≥1% NSCLC.

The interim analysis results show that compared with pembrolizumab monotherapy, the combination of sac-TMT and pembrolizumab significantly prolongs progression-free survival (PFS) and reduces the risk of disease progression or death, with a hazard ratio (HR) of 0.35. Consistent PFS benefits were observed across all prespecified subgroups, including by PD-L1 expression level and histological type, with PFS HRs of 0.47 and 0.28 for the PD-L1 TPS ≥50% and 1–49% subgroups, respectively, and PFS HRs of 0.28 and 0.44 for the non-squamous and squamous subgroups, respectively. A positive trend in overall survival (OS) was also observed, with an HR of 0.55. Furthermore, the overall safety profile of sac-TMT in combination with pembrolizumab was manageable, consistent with the established safety profiles of sac-TMT alone or pembrolizumab alone, and no new safety signals identified.

This is the first Phase III trial of an ADC combined with an immune checkpoint inhibitor to meet its primary endpoint in the first line treatment of NSCLC, and for the first time demonstrate that "ADC+IO" combination of sac-TMT plus pembrolizumab has the potential to achieve survival benefit as first‑line therapy for NSCLC. The publication of these findings in The Lancet further signifies that the clinical and academic value of this combination therapy has received internationally recognized validation.

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the National Medical Products Administration (NMPA).

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the new drug application (NDA) stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, May 30, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company", 6990.HK) announced today that at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, the results of the Phase III clinical study OptiTROP-Lung05, evaluating the company's TROP2 ADC sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870)(佳泰莱^®) in combination with pembrolizumab (KEYTRUDA^®[1], MSD's anti-programmed cell death protein 1 (PD-1) antibody) as first-line treatment for Programmed Death-Ligand 1 (PD-L1) Tumor Proportion Score (TPS)≥1% non-small cell lung cancer (NSCLC), was presented as an oral presentation by Professor Caicun Zhou from Shanghai East Hospital, Tongji University (Abstract #8506, Lung Cancer – Metastatic Non-Small Cell).

Sac-TMT is designed with a unique, bifunctional linker and differentiated belotecan-derivative payload. The linker is conjugated via cysteine, which maximizes payload delivery to tumor cells both through its irreversible connection with the high-affinity and targeting anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a moderately toxic novel topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4.

In the OptiTROP-Lung05 study, a total of 413 patients were randomized (1:1) to receive either sac-TMT in combination with pembrolizumab or pembrolizumab monotherapy.

As of the data cutoff date (September 29, 2025), with a median follow‑up of 10.5 months, the study demonstrated that:

• Progression-free survival (PFS) showed statistically significant and clinically meaningful benefit in sac-TMT plus pembrolizumab compared with pembrolizumab alone. The median PFS assessed by blinded independent central review (BICR) was not reached (NR) vs 5.7 months (HR=0.35; 95% CI: 0.26-0.47; p<0.0001). The 12-month PFS rate was 62.4% vs 29.0%.

• Consistent benefit across prespecified subgroups: In patients with PD‑L1 TPS ≥50% and TPS 1–49%, the PFS HRs were 0.47 (95% CI: 0.29–0.77) and 0.28 (95% CI: 0.19–0.41), respectively. In patients with non‑squamous and squamous NSCLC, the PFS HRs were 0.28 (95% CI: 0.18–0.43) and 0.44 (95% CI: 0.29–0.66), respectively.

• Overall survival (OS) was not yet mature but showed a positive trend: median OS was NR vs 14.5 months (HR = 0.55; 95% CI: 0.36–0.85). The 12‑month OS rate was 80.4% vs 68.9%.

• The combination group showed improvements over pembrolizumab monotherapy group in objective response rate (ORR) (70.2% vs 42.0%), deep response rate (49.0% vs 25.9%), and 12-month duration of response rate (77.7% vs 59.4%).

The incidence of grade ≥3 treatment-emergent adverse events (TEAEs) was higher in the combination group, primarily driven by the expected hematologic adverse events of sac-TMT. Incidence of discontinuation of pembrolizumab due to TEAEs was similar in both groups. No sac-TMT-related deaths occurred. Adverse events of special interest (AEOSIs) were consistent with the known safety profiles of each individual agent, and no new safety signals were identified.

The interim analysis results show that sac-TMT plus pembrolizumab significantly prolonged PFS and reduced the risk of disease progression or death compared with pembrolizumab alone, with consistent PFS benefits observed across all prespecified subgroups (including PD‑L1 expression levels and histological subtypes). A positive trend in OS was also observed. Furthermore, the overall safety profile of sac-TMT in combination with pembrolizumab was manageable, consistent with the established safety profiles of sac-TMT alone or pembrolizumab alone.

Notably, the findings of OptiTROP-Lung05 have been simultaneously published in The Lancet（Impact Factor=88.5）, indicating that its clinical and academic value has received dual recognition from a leading international academic conference and an authoritative journal.

Professor Caicun Zhou, the national leading principal investigator from Shanghai East Hospital, Tongji University, said: "The positive results of the OptiTROP‑Lung05 study are encouraging. The study not only supports the application of sac‑TMT in an earlier-line setting for lung cancer, but also provides evidence of the 'ADC+IO' synergistic strategy being evaluated in the first-line setting for PD‑L1‑positive advanced NSCLC, potentially bringing a new option to a broad population of patients with lung cancer."

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the National Medical Products Administration (NMPA).

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, May 30, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company", 6990.HK) announced that at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting held in Chicago, USA, results from the pivotal Phase II study of the Company's next-generation selective RET inhibitor, lunbotinib fumarate (A400/EP0031, 宁泰莱^®[1]), in advanced rearranged during transfection (RET) fusion-positive non-small cell lung cancer (NSCLC) were presented as an oral report by Professor Qing Zhou from Guangdong Provincial People's Hospital (Abstract #8505, Lung Cancer—Metastatic Non-Small Cell). Based on these results, a New Drug Application (NDA) for lunbotinib fumarate for the treatment of adult patients with locally advanced or metastatic RET fusion-positive NSCLC has been accepted by the National Medical Products Administration (NMPA) of China.

The study enrolled 71 patients who had previously received platinum-based chemotherapy and immunotherapy (pre-treated patients) and 92 patients who had not received prior systemic therapy (treatment-naïve patients). As of the data cutoff date of October 29, 2025, the median follow-up was 22.6 months and 20.7 months, respectively.

The confirmed objective response rate (ORR) assessed by Independent Review Committee (IRC) was 81.3% (95% CI: 71.8–88.7) in treatment-naïve patients and 87.1% (95% CI: 77.0–93.9) in pre-treated patients.

In treatment-naïve patients, median duration of response (mDOR) and median progression-free survival (mPFS) were not reached. In pre-treated patients, mDOR was 25.7 months, and mPFS was 27.5 months.

Among 40 patients with central nervous system (CNS) metastases at baseline (assessed by IRC per response assessment in neuro-oncology brain metastases (RANO-BM) criteria), the intracranial complete response (CR) rate was 30%, and the disease control rate (DCR) was 92.5% (95% CI: 79.6–98.4).

Lunbotinib fumarate was well tolerated, with treatment-related adverse events (TRAEs) being predominantly Grade 1–2. The rate of permanent discontinuation due to TRAEs was 1.2%, and no treatment-related deaths were reported.

The study shows that lunbotinib fumarate demonstrated robust and durable clinical activity in RET fusion-positive NSCLC, regardless of line of therapy, in a largely poor-prognostic patient population. Favorable CNS efficacy was observed in patients with measurable baseline CNS metastases. The safety profile was manageable, with no unexpected safety signals.

Professor Qing Zhou, principal investigator from Guangdong Provincial People's Hospital, said: "From the first presentation of Phase I data at ASCO 2023 to today's pivotal Phase II results, we have witnessed the progression of lunbotinib fumarate from early exploration to a confirmatory study. These data show that lunbotinib fumarate delivers robust and durable responses in both treatment-naïve and pre-treated patients with RET fusion-positive NSCLC, with particularly remarkable intracranial efficacy in patients with CNS metastases at baseline. As a next-generation selective RET inhibitor, it will offer an important new treatment option for patients."

About lunbotinib fumarate (A400/EP0031, 宁泰莱^®)

Lunbotinib fumarate is a novel, next-generation selective RET inhibitor for NSCLC, medullary thyroid cancer (MTC) and other solid tumors with a high prevalence of RET alterations. The NDA of lunbotinib fumarate has been accepted for review by the NMPA of China for the treatment of adult patients with RET-fusion positive locally advanced or metastatic NSCLC. The Company is also conducting a Phase Ib/II clinical study in China for the treatment of RET-positive solid tumors.

In March 2021, the Company granted Ellipses Pharma Limited, a U.K.-based international oncology drug development company, an exclusive license to develop, manufacture and commercialize this agent outside Greater China and certain Asian countries. In April 2024, lunbotinib fumarate was cleared by the Food and Drug Administration (FDA) to progress into a Phase II clinical trial (NCT05443126) which is currently recruiting in the United States, United Kingdom, Europe and United Arab Emirates, where it is being evaluated as a monotherapy and in combination with chemotherapy in RET fusion positive advanced NSCLC.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

• Sacituzumab tirumotecan (sac-TMT)(佳泰莱^®) plus pembrolizumab versus pembrolizumab as first-line treatment for PD-L1 positive advanced NSCLC: Results from the randomized, controlled, registrational Phase III OptiTROP-Lung05 study (Abstract #8506)
• Efficacy and safety of lunbotinib fumarate (A400/EP0031,宁泰莱^®[1]), a next-generation selective RET inhibitor (SRI), from a pivotal registrational Phase Ⅱ study in patients with advanced RET-fusion positive NSCLC (Abstract #8505)

CHENGDU, China, May 22, 2026 /PRNewswire/ -- The 2026 American Society of Clinical Oncology (ASCO) Annual Meeting will be held in Chicago from May 29 to June 2, local time. Two registrational studies of the trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT)(佳泰莱^®) and the next‑generation selective rearranged during transfection (RET) inhibitor lunbotinib fumarate (A400/EP0031,宁泰莱^®) from Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) have been selected for oral presentation session on Lung Cancer – Non-Small Cell Metastatic. The full text of the related abstracts were published on the ASCO official website^[2] on May 21, 2026, local time. Key highlights are summarized as follows:

Study 1

Sacituzumab tirumotecan (sac-TMT) plus pembrolizumab versus pembrolizumab as first-line treatment for PD-L1 positive advanced non-small cell lung cancer (NSCLC): Results from the randomized, controlled Phase III OptiTROP-Lung05 study, to be presented as an oral presentation scheduled on May 29, 2026, 3:12 PM-3:24 PM CDT (Abstract #8506: Lung Cancer – Non-Small Cell Metastatic)

A total of 413 patients with previously untreated locally advanced or metastatic NSCLC without epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) alterations and with programmed death ligand 1 (PD-L1) positive (defined as tumor proportion score (TPS) ≥1%), covering both squamous and non‑squamous histologies, were enrolled and randomized (1:1) to receive sac-TMT (4mg/kg Q2W) plus pembrolizumab (400mg Q6W) or pembrolizumab monotherapy (400mg Q6W). The primary endpoint was progression‑free survival (PFS) assessed by blinded independent central review (BICR), and the key secondary endpoint was overall survival (OS). As of September 29, 2025, the median follow-up was 10.5 months.

The results demonstrated that：

• Significant PFS improvement: PFS assessed by BICR was significantly improved in the sac-TMT plus pembrolizumab group compared with the pembrolizumab group, with a median PFS of not reached (NR) versus 5.7 months (hazard ratio (HR)=0.35; 95% confidence interval (CI): 0.26–0.47; p<0.0001).
• Substantially higher response rate: The objective response rate (ORR) assessed by BICR was 70.2% in the sac-TMT plus pembrolizumab group versus 42.0% in the pembrolizumab group.
• Positive OS trend though immature (HR=0.55; 95% CI: 0.36–0.85).
• Consistent benefit across prespecified subgroups: the HR for PFS in patients with PD-L1 TPS 1-49% and TPS ≥ 50% were 0.28 (95% CI, 0.19-0.41) and 0.47 (95% CI, 0.29-0.77), respectively; the HR for PFS in patients with non-squamous and squamous NSCLC were 0.28 (95% CI, 0.18-0.43) and 0.44 (95% CI, 0.29-0.66).

In terms of safety, grade≥ 3 treatment-emergent adverse events (TEAEs) occurred in 55.3% of patients in the sac-TMT plus pembrolizumab group versus 31.4% in the pembrolizumab group. TEAEs leading to permanent discontinuation of sac-TMT and pembrolizumab occurred in 3.8% and 5.3% of patients, respectively, while TEAEs leading to permanent discontinuation occurred in 4.9% of patients in the pembrolizumab group.

OptiTROP-Lung05 is the first Phase III clinical study demonstrating a significant improvement in PFS and a positive trend in OS with an ADC combined with pembrolizumab compared to pembrolizumab in first-line treatment for PD-L1 positive advanced NSCLC. Based on these results, a supplemental New Drug Application (sNDA) for this combination regimen has been accepted for review and included in the priority review and approval process by the National Medical Products Administration (NMPA) in China.

Study 2

Efficacy and safety of lunbotinib (A400/EP0031), a next-generation selective RET inhibitor (SRI), from a pivotal phase Ⅱ study in patients with advanced RET-fusion positive non-small cell lung cancer (NSCLC), to be presented as an oral presentation scheduled on May 29, 2026, 2:36 PM-2:48 PM CDT (Abstract #8505: Lung Cancer – Non-Small Cell Metastatic)

As of October 29, 2025, 71 patients with prior platinum-based chemotherapy and immunotherapy (pre-treated patients) and 92 patients who had not received prior systemic therapy (treatment-naïve patients) were enrolled, with median follow-up of 22.6 and 20.7 months.

The study demonstrated that：

• Independent Review Committee (IRC)-assessed confirmed ORR was 87.1% (95% CI: 77.0-93.9) in pre-treated patients and 81.3% (95% CI: 71.8-88.7) in treatment-naïve patients;
• Median PFS was 27.5 months in pre-treated patients (immature) and NR in treatment-naïve patients, with 24-month PFS rates of 52.1% and 59.9%, respectively;
• Median OS was not reached in either group, with 24-month OS rates of 65.7% in pre-treated patients and 74.1% in treatment-naïve patients.
• Among patients with baseline brain metastases (23 pre-treated, 16 treatment-naïve), ORR was 82.6% and 75.0%, respectively, and 6 patients in each cohort had complete intracranial response.

The safety profile was manageable, with no new signals identified. Grade ≥ 3 treatment-related adverse events (TRAEs) occurred in 40.5% of patients. Only two patients (1.2%) permanently discontinued treatment due to TRAEs. No fatal TRAEs occurred.

Based on the results of this study, the new drug application (NDA) for lunbotinib fumarate for the treatment of adult patients with RET fusion-positive locally advanced or metastatic NSCLC has been accepted for review by the NMPA.

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR–tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer.  A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®[3]) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and ALK-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Lunbotinib Fumarate (A400/EP0031,宁泰莱^®)

Lunbotinib fumarate is a novel, next-generation selective RET inhibitor for NSCLC, medullary thyroid cancer (MTC) and other solid tumors with a high prevalence of RET alterations. The NDA of lunbotinib fumarate has been accepted for review by the NMPA of China for the treatment of adult patients with RET-fusion positive locally advanced or metastatic NSCLC. The Company is also conducting a Phase Ib/II clinical study in China for the treatment of RET-positive solid tumors.

In March 2021, the Company granted Ellipses Pharma Limited, a U.K.-based international oncology drug development company, an exclusive license to develop, manufacture and commercialize this agent outside Greater China and certain Asian countries. In April 2024, lunbotinib fumarate was cleared by the Food and Drug Administration (FDA) to progress into a Phase II clinical trial (NCT05443126) which is currently recruiting in the United States, United Kingdom, Europe and United Arab Emirates, where it is being evaluated as a monotherapy and in combination with chemotherapy in RET fusion positive advanced NSCLC.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

OptiTROP-Breast03 is a randomized, open‑label, multicenter Phase III clinical study designed to evaluate the efficacy and safety of sac‑TMT versus investigator's choice of chemotherapy in patients with unresectable recurrent or metastatic TNBC who have not received prior systemic therapy for advanced disease. The enrolled population includes patients with programmed death ligand 1 (PD-L1)‑negative expression, as well as those with PD‑L1‑positive expression who have relapsed after prior anti-PD-(L)1 inhibitor in early stage disease. Two independent primary endpoints of the study are PFS and OS. At this pre-specified interim analysis, sac-TMT monotherapy demonstrated a statistically significant and clinically meaningful improvement in PFS. OS data are immature, a positive trend is currently observed. Follow-up will continue per protocol and further evaluation will be conducted in subsequent prespecified analyses. The safety profile of sac-TMT was consistent with that observed in previously reported studies, and no new safety signals were observed. Based on the results from the interim analysis, the Company plans to communicate with the Center for Drug Evaluation (CDE) of the National Medical Products Administration of China regarding the subsequent regulatory pathway for sac‑TMT in this indication.

This is the first registrational Phase III clinical study of sac-TMT to achieve positive results in the first-line treatment of TNBC. Previously, sac-TMT has been approved for the treatment of unresectable locally advanced or metastatic TNBC in patients who have received at least two prior systemic therapies (including at least one for advanced or metastatic disease) based on the results of OptiTROP-Breast01 study. The achievement of the primary endpoint of PFS in the Phase III OptiTROP-Breast03 study builds on the ongoing development of sac-TMT and supports further evaluation of its potential in the first-line setting in TNBC and across treatment settings, aligned with the Company's broader clinical development strategy to address patient needs.

Currently, the global Phase III TroFuse-011 study (NCT06841354) of sac-TMT monotherapy or in combination with pembrolizumab as first-line treatment for PD-L1 Combined Positive Score (CPS)＜10 TNBC is ongoing.

About sac-TMT(佳泰莱^®)

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as non-small cell lung cancer (NSCLC), breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR–tyrosine kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and ALK-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD has initiated 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, May 12, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that it has received a clinical trial notice from the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) approving the Investigational New Drug (IND) application for PD-1 x VEGF bispecific antibody SKB118 (also known as CR-001) for the treatment of advanced solid tumors.

In December 2025, Kelun-Biotech and Crescent Biopharma ("Crescent") entered into a strategic collaboration for SKB118/CR-001. Under the collaboration, Crescent granted Kelun-Biotech exclusive rights to research, develop, manufacture and commercialize SKB118/CR-001 in Greater China (including Mainland China, Hong Kong, Macau, and Taiwan). In January 2026, Crescent announced the regulatory clearance of the IND application for SKB118/CR-001 by the U.S. Food and Drug Administration (FDA) to initiate its global ASCEND Phase I/II clinical trial (NCT07335497) for the treatment of locally advanced or metastatic solid tumors. The trial is ongoing and expected to initially enroll up to 290 patients.

Dr. Michael Ge, CEO of Kelun-Biotech, stated: "We are pleased to see the approval of the IND application for SKB118 in China, which marks the simultaneous advancement of clinical development in China and globally. Since entering into the collaboration with Crescent, we have worked closely and leveraged complementary advantages with each other to efficiently drive the R&D of the collaborative product candidates. Based on our ADC+IO strategies, we will actively explore the potential of combining SKB118 with our proprietary ADC assets to unlock the synergistic value of our portfolio and expand more treatment possibilities for cancer patients."

About SKB118 (also known as CR-001)

SKB118 is a tetravalent bispecific antibody being developed for the treatment of solid tumors that combines two complementary, validated mechanisms in oncology via a blockade of PD-1 and VEGF. PD-1 checkpoint inhibition is aimed at restoring T cells' ability to recognize and destroy tumor cells, and blocking VEGF is intended to reduce blood supply to tumor cells and to inhibit tumor growth. In preclinical studies, SKB118 demonstrated cooperative pharmacology with increased binding to PD-1 and signal blockade in the presence of VEGF as well as robust anti-tumor activity. SKB118's anti-VEGF activity may also normalize the vasculature at the tumor site, which has the potential to improve the localization and effectiveness of combination therapies, such as in combination with antibody-drug conjugates (ADCs).

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/

CHENGDU, China, May 8, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company") announced that the sNDA (the "Application") for the Company's TROP2 ADC sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®) was accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China. The application is for sac-TMT in combination with MSD's^[1] anti-PD-1 monoclonal antibody pembrolizumab (KEYTRUDA^®[2]) as first‑line treatment for adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who have PD-L1 tumor proportion score (TPS) ≥1% and are EGFR-negative and ALK-negative. This acceptance is based on the positive results from the OptiTROP-Lung05 registrational Phase III study, and the application is the fifth indication application for sac-TMT that has been accepted by the NMPA.

The OptiTROP-Lung05 is a randomized, open-label, multicenter, Phase III clinical study that evaluates the efficacy and safety profile of sac-TMT in combination with pembrolizumab versus pembrolizumab monotherapy as first-line treatment for PD-L1-positive locally advanced or metastatic NSCLC. At a pre-specified interim analysis, the study has met its primary endpoint of progression-free survival (PFS) and demonstrated a statistically significant and clinically meaningful improvement as concluded by the Independent Data Monitoring Committee (IDMC). A positive trend in overall survival (OS) was also observed. Notably, the OptiTROP-Lung05 study is the first Phase III study of an immunotherapy and ADC combination to meet its primary endpoint in first-line NSCLC treatment. The study has been selected for an oral presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract number #8506, Lung Cancer –Non-Small Cell Metastatic).

Previously, sac-TMT in combination with intravenous and subcutaneous pembrolizumab for the first-line treatment of patients with locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and ALK-negative was granted Breakthrough Therapy Designation (BTD) by the NMPA. On April 9, 2026, the CDE's official website announced that the Application has entered the priority review and approval process. This marks the fifth sac-TMT indication to enter the CDE's priority review and approval process. Through this process, the review time will be significantly shortened, potentially expediting its approval pathways.

Dr. Michael Ge, CEO of Kelun-Biotech said, "We are delighted to see the acceptance of the fifth indication application for sac-TMT. Compared to immunotherapy alone, the ADC combination with KEYTRUDA^® as first-line treatment for PD-L1-positive NSCLC has achieved not only positive results in PFS, but also a trend toward benefit in OS. This achievement holds significant importance for improving current treatment regimens for lung cancer. We will continue to collaborate with our partners to advance the clinical development and commercialization of sac-TMT, to help more patients with lung cancer and enhance their survival outcomes."

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) BC who have received prior ET and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®) as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and ALK-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD has initiated 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/. 

CHENGDU, China, April 22, 2026 /PRNewswire/ -- The 2026 American Society of Clinical Oncology (ASCO) Annual Meeting will be held in Chicago from May 29 to June 2. In this meeting, Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (6990.HK) will present results from three clinical studies, including data from its TROP2 ADC sacituzumab tirumotecan (sac-TMT, 佳泰莱^®), next-generation selective RET inhibitor lunbotinib fumarate (A400/EP0031, 宁泰莱^®[1]) and novel ADC SKB500. The abstracts for these studies will be published on the ASCO official website on May 21, 2026, local time.

Detailed information on the studies selected for 2026 ASCO is as follows:

Title: Sacituzumab tirumotecan (sac-TMT) plus pembrolizumab (P) versus pembrolizumab (P) as first-line treatment for PD-L1-positive advanced non-small cell lung cancer (NSCLC): Results from the randomized, controlled phase III OptiTROP-Lung05 study
Presentation Type: Oral
Abstract Number: 8506
Session Date and Time: May 29, 3:12 PM-3:24 PM CDT | Lung Cancer-Non-Small Cell Metastatic

Title: Efficacy and safety of lunbotinib (A400/EP0031), a next-generation selective RET inhibitor (SRI), from a pivotal phase Ⅱ study in patients with advanced RET fusion-positive non-small cell lung cancer (NSCLC)
Presentation Type: Oral
Abstract Number: 8505
Session Date and Time: May 29, 2:36 PM-2:48 PM CDT | Lung Cancer-Non-Small Cell Metastatic

Title: An open-label, first-in-human study of SKB500 in patients with locally advanced or metastatic solid tumors
Presentation Type: Rapid oral
Abstract Number: 3011
Session Date and Time: June 2, 9:57 AM-10:03 AM CDT | Molecularly Targeted Agents and Tumor Biology

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting);2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) BC who have received prior ET and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About A400/EP0031

A400/EP0031 novel next-generation selective RET inhibitor for NSCLC, medullary thyroid cancer (MTC) and other solid tumors with a high prevalence of RET alterations. The NDA of A400/EP0031 has been accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the treatment of adult patients with RET-fusion positive locally advanced or metastatic NSCLC. The Company is also conducting a Phase Ib/II clinical study in China for the treatment of RET-positive solid tumors.

In March 2021, the Company granted Ellipses Pharma Limited, a U.K.-based international oncology drug development company, an exclusive license to develop, manufacture and commercialize this agent outside Greater China and certain Asian countries. In April 2024, A400/EP0031 was cleared by the Food and Drug Administration (FDA) to progress into a Phase II clinical trial (NCT05443126) which is currently recruiting in the United States, United Kingdom, Europe and United Arab Emirates, where it is being evaluated as a monotherapy and in combination with chemotherapy in RET fusion positive NSCLC.

About SKB500

SKB500, a novel, proprietary ADC developed via the OptiDC™ platform, is designed to leverage specific target biology through a validated target combined with a differentiated payload-linker strategy. In preclinical investigations, SKB500 demonstrated a favorable therapeutic window with robust efficacy and manageable safety profiles across multiple advanced solid tumors.

Currently, a Phase II exploratory study of SKB500 in combination with immunotherapy with or without chemotherapy as first-line treatment for extensive-stage small cell lung cancer (ES-SCLC) is ongoing in China.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, April 14, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that results from both the ovarian cancer cohort and the cervical cancer cohort of Phase II study SKB264-II-06/MK-2870-002 of the TROP2 ADC sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®), in combination with MSD's^[1] anti-PD-1 monoclonal antibody pembrolizumab (KEYTRUDA^®[2]), were selected for oral presentation at the 2026 Society of Gynecologic Oncology (SGO) Annual Meeting in San Juan, Puerto Rico. The data were presented by Professor Xiaohua Wu of Fudan University Shanghai Cancer Center.

Ovarian cancer

This presentation reported, for the first time, important data on sac-TMT as maintenance treatment in breast cancer susceptibility gene (BRCA) wild-type, second-line platinum-sensitive recurrent ovarian cancer. Among the 40 patients enrolled in the ovarian cancer cohort, 27 received sac-TMT (4 mg/kg, every other week (Q2W)) in combination with pembrolizumab, and 13 received sac-TMT (5 mg/kg, Q2W) in combination with pembrolizumab. Among the enrolled patients, 70% had prior bevacizumab therapy, and 58% had prior PARP inhibitor therapy. The median follow-up was 22.2 months (data cutoff date: November 17, 2025).

The data showed that median progression-free survival (PFS) in the overall population was 20.9 months; median overall survival (OS) was not reached; and the 12-month OS rate was 92%. Additionally, the adverse events of sac-TMT in combination with pembrolizumab were manageable. The most common treatment-related adverse events (TRAEs) were anemia, stomatitis, and decreased neutrophil count. No deaths or discontinuations due to sac-TMT-related TRAEs was reported.

The study results showed that sac-TMT in combination with pembrolizumab as maintenance therapy for platinum-sensitive recurrent ovarian cancer demonstrated positive efficacy signals and a favorable safety profile, providing important evidence for further clinical exploration of this combination regimen in the ovarian cancer population.

Cervical cancer

A total of 68 patients with previously treated second-line or third-line recurrent or metastatic cervical cancer were enrolled in the cervical cancer cohort to receive sac-TMT at doses of 3 mg/kg, 4 mg/kg, or 5 mg/kg Q2W in combination with pembrolizumab. Among the enrolled patients, 57% had prior bevacizumab therapy, and 51% had prior immunotherapy. The median follow-up was 24.7 months (data cutoff date: November 17, 2025).

The data showed that after treatment with sac-TMT in combination with pembrolizumab, the objective response rate (ORR) in the total population was 51% and 54% in IO-pretreated population. The median PFS was 7.3 months and the median OS reached 18.9 months in the total population. Furthermore, the safety profile of sac-TMT in combination with pembrolizumab was manageable, with no new safety signals identified and no deaths due to TRAEs.

The study results demonstrated promising and durable antitumor activity with a manageable safety profile in patients with pre-treated second-line or third-line recurrent or metastatic cervical cancer receiving sac-TMT in combination with pembrolizumab, providing robust data to support further clinical development.

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor in the lysosome, with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) BC who have received prior ET and at least one line of chemotherapy in advanced setting. The first two indications listed above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinical benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing Phase III global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, April 9, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) today announced that following an application to The Stock Exchange of Hong Kong Limited (the "Stock Exchange") pursuant to Rule 18A.12 of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited (the "Listing Rules"), the Stock Exchange has approved the dis-application of Rules 18A.09 to 18A.11 of the Listing Rules to the Company. As the Company has satisfied the relevant requirements under the Listing Rules, it has been approved by the Stock Exchange to remove the "B" marker from its stock code, effective from April 14, 2026. The removal of the "B" marker signifies that Kelun-Biotech has met higher standards in key operating metrics, representing a new stage of development for the Company.

The essence of this "new stage of development" is reflected across three major dimensions: accelerated R&D and product launch, achievement of global collaboration milestones, and iteration of innovative assets.

• Accelerated product approvals and significant time-to-market efficiency: Within three years since its listing, Kelun-Biotech has already secured approvals for 4 products across 8 indications, among which 3 products with 5 indications have been included in China's National Reimbursement Drug List (NRDL), accomplishing a fully integrated platform spanning from R&D to commercialization. Leveraging this end-to-end drug development platform, the Company will further advance its pipeline to address unmet medical needs in oncology and other major disease areas.
• Steady progress in global partnerships with anticipated milestones: The Company continues to expand its global footprint through collaborations with world leading partners, including MSD and Crescent Biopharma, steadily advancing the global development of relevant assets. Notably, MSD has evaluated 17 global Phase III clinical trials for sacituzumab tirumotecan (sac-TMT, 佳泰莱^®), and multiple studies are approaching the data readout stage and further achieving more important milestones.
• Successive innovation from best-in-class (BIC) to first-in-class (FIC): Leveraging its leading technology platforms in ADC and novel conjugation drugs, biologics, and small molecules, the Company has built a differentiated innovative pipeline. So far, sac-TMT has demonstrated strong competitiveness worldwide as a representative BIC potential asset. Moreover, the Company is advancing a portfolio of potential FIC candidates integrating new targets, new mechanisms, and new technologies, continuously expanding the boundaries of original innovation and further strengthening its long-term sustainable development.

Dr. Michael Ge, CEO of Kelun-Biotech, said: "We are pleased that our company has met the relevant requirements under the HKEX Listing Rules and has successfully removed the 'B' marker from its stock code. This milestone reflects our strong capabilities in biopharmaceutical innovation and value realization. Supported by a solid financial position, we will continue to enrich our innovative and synergistic pipeline, accelerate product development, benefit a broader patient population and create long-term value for shareholders."

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/. 

CHENGDU, China, March 24, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) today announced that the Investigational New Drug (IND) application for SKB103, its self-developed novel bispecific antibody-drug conjugate with combined Tumor-Associated Antigen-targeting and Immuno-Oncology mechanisms (TAA-PD-L1 bsADC), has been approved by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the treatment of advanced solid tumors. The approval marks SKB103 as the Company's first TAA-PD-L1 bsADC candidate and its second bsADC program for tumor therapy to enter the clinical stage, following SKB571.

As one of the industry leaders in the ADC field, Kelun-Biotech has established a solid competitive advantage. Currently, the Company's self-developed TROP2 ADC and HER2 ADC have been approved for marketing, demonstrating significant clinical efficacy and competitive differentiation. Focusing on advances in oncology therapeutics, Kelun-Biotech continues to expand its innovative layout by building a diversified pipeline covering cutting-edge therapies such as RDCs and bsADCs and fully driving breakthroughs and innovations in existing cancer treatment paradigms.

SKB103 is a potential best-in-class novel bsADC developed using Kelun-Biotech's proprietary OptiDC™ platform. Designed as a single molecule, it is expected to realize targeted delivery of cytotoxic payloads to tumors and modulation of tumor immune microenvironment simultaneously. In preclinical studies, SKB103 demonstrated outstanding anti-tumor activity and a favorable safety profile. The therapeutic potential of SKB103 will support its subsequent clinical development.

"The IND approval for SKB103 represents another important milestone in our bsADCs pipeline and reflects the continued clinical translation of our novel DC strategy, further solidifying our core technical advantages in the ADC field," said Dr. Michael Ge, CEO of Kelun-Biotech. "Innovation in IO and ADC is currently reshaping the global cancer treatment landscape. Leveraging our systematic and platform-based R&D capabilities and extensive ADC development experience, we will advance the development of next-generation ADC drugs like SKB103, deeply explore the global clinical value of our portfolio, and fully promote innovation in cancer therapies, opening up broader prospects for the treatment of patients worldwide and the Company's sustainable development."

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

• Revenue amounted to approximately RMB2057.92 million, and gross profit amounted to approximately RMB1478.78 million, representing a year-on-year increase.
• R&D Expenses was approximately RMB1319.68 million.
• Loss for the period was RMB381.97 million, adjusted annual loss^[1] was approximately RMB211.28 million.
• Cash and financial assets^[2] amounted to approximately RMB4559.36 million, with ample cash reserves.
• The debt-to-asset ratio^[3] further declined to 18.7%.

CHENGDU, China, March 24, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Pharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", Stock Code: 6990.HK) announced its audited consolidated results for the year ended 31 December 2025 (the "Reporting Period").

Kelun-Biotech is leveraging its core strengths and proprietary OptiDC™ technology platform to continue deepening its presence in the ADC and novel DC drug field. The company is actively advancing cutting-edge modalities including bispecific ADCs, RDCs, iADCs, and DACs, building a differentiated pipeline with strong global competitiveness. At the same time, Kelun-Biotech is steadily advancing product commercialization, achieving transformational growth across its business. To date, the company has four products with eight indications approved for marketing in China, including Sacituzumab Tirumotecan (佳泰莱^®), Trastuzumab Botidotin (舒泰莱^®), Tagitanlimab (科泰莱^®), and Cetuximab N01 (达泰莱^®). Among them, three products with five indications have been included in the 2025 National Reimbursement Drug List (NRDL), establishing a fully integrated drug development ecosystem that spans R&D through commercialization.

As of now, the company has built a robust pipeline of more than 30 drug candidates, with over 10 in the clinical stage, and are gradually expanding into broader non-oncology therapeutic areas such as autoimmune diseases and metabolic disorders. Looking ahead, the company will leverage its innovative and differentiated pipeline to deliver high-quality therapeutic solutions for major unmet medical needs worldwide.

Core ADC Products' Commercialization Realized to Solidify Long-term Performance Foundation 

Sac-TMT (sacituzumab tirumotecan, TROP2 ADC) (also known as SKB264/MK-2870) (佳泰莱^®)

TNBC:

• The Company received marketing authorization in China from the NMPA for sac-TMT in adult patients with unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting).
• The Company has initiated a Phase 3 registrational study of sac-TMT monotherapy versus ICC for 1L advanced TNBC.

HR+/HER2- BC:

• In February 2026, a new indication application for sac-TMT for the treatment of adult patients with HR+/HER2- BC who have received prior endocrine therapy (ET) and at least one line of chemotherapy in advanced setting has been approved for marketing by the NMPA.
• A Phase 3 registrational study of sac-TMT versus ICC for treatment of patients with HR+/HER2- BC who received prior ET is in progress.

EGFR-mutant NSCLC:

• In March 2025, the Company received marketing authorization in China from the NMPA for sac-TMT for the treatment of adult patients with EGFR mutant-positive NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy. This is the first TROP2 ADC drug approved for marketing in LC globally.
• In October 2025, the company received marketing authorization in China from the NMPA for sac-TMT for the treatment of adult patients with EGFR mutant-positive NSCLC who progressed after treatment with EGFR-TKI therapy. This is the first ADC globally to show an OS benefit compared with platinum doublet chemotherapy and be approved for advanced NSCLC following progression on only TKI therapy (2L).
• The Phase 3 registrational study of sac-TMT combined with osimertinib as first-line treatment of EGFR-mutant NSCLC and a Phase 2 study of sac-TMT monotherapy or in combination with osimertinib as neoadjuvant therapy for EGFR-mutant NSCLC are in progress.

EGFR-wild type NSCLC:

• The Phase 3 registrational study of sac-TMT in combination with KEYTRUDA®^[1] (pembrolizumab) versus pembrolizumab as first-line treatment of PD-L1 positive NSCLC met its primary endpoint. This is the first Phase 3 clinical trial of ADC combined with immune checkpoint inhibitor to achieve its primary endpoint in the first-line treatment of NSCLC.
• In January 2026, sac-TMT in combination with pembrolizumab for the first-line treatment of PD-L1 positive NSCLC were granted Breakthrough Therapy Designation by the NMPA.
• The Phase 3 registrational study of sac-TMT in combination with pembrolizumab as first-line treatment of PD-L1 negative NSCLC is in progress.

Other indications: The company is actively exploring the potential of sac-TMT both as a monotherapy and in combination with other therapies for treating other solid tumors, including GC, EC, CC, OC, UC, CRPC, HNSCC, and TC, etc.

Trastuzumab botidotin (HER2 ADC, also known as A166, 舒泰莱^®)

• In October 2025, trastuzumab botidotin was approved for marketing by the NMPA for adult patients with HER2+ BC who have received one or more prior anti-HER2 therapy. This is the first domestically developed HER2 ADC approved for 2L+ HER2+ BC in China.
• An open, multicenter Phase 2 clinical study of trastuzumab botidotin in the treatment of HER2+ BC that previously received a topoisomerase inhibitor ADC is in progress.

Key Clinical Data Highlighted at International Academic Conferences and in Top Journals

• Results from the Phase 3 study of sac-TMT for the treatment of 2L EGFR-mutant NSCLC were selected for LBA and presented as an oral report in the Presidential Symposium session at the 2025 ESMO Congress. Sac-TMT achieved statistically significant and clinically meaningful improvements in ORR, PFS, and OS compared to chemotherapy. The study findings were published simultaneously online at the New England Journal of Medicine and in the first issue of 2026.
• Results from the study of sac-TMT for the treatment of 3L EGFR-mutant NSCLC were presented as an oral report at the ASCO Annual Meeting and published at the British Medical Journal. The final OS analysis of this study will be selected for LBA and presented as a mini oral report at the 2026 ELCC.
• Results from the Phase 3 study of sac-TMT for the treatment of 2L+ HR+/HER2-BC were selected for LBA and presented as an oral report at the 2025 ESMO Congress.
• Results from the Phase 3 study of trastuzumab botidotin for the treatment of 2L+ HER2+ BC were selected for LBA and presented as an oral report at the 2025 ESMO Congress.

Sustained Value Release of ADCs Under Development with Tiered Advancement of Innovation Pipeline

Phase 2 clinical stage

SKB315 (CLDN18.2 ADC):

• The Phase 1b clinical trial of SKB315 is in progress, for the treatment of GC/GEJC/PDAC, etc.
• Results of a Phase 1 study of SKB315 in patients with advanced solid tumors including GC/GEJC were presented at 2025 ESMO Congress in October 2025.

SKB410/MK-3120 (Nectin-4 ADC):

• Its partner MSD has launched 4 global Phase 1/2 clinical trial of SKB410/MK-3120 in advanced solid tumor including bladder cancer, etc.

SKB571/MK-2750 (novel bsADC): The Phase 2 clinical trial in China is ongoing.

SKB518 (novel ADC with a potential FIC target): The Phase 2 clinical trials are ongoing in China.

SKB500 (novel ADC): The Phase 2 study is ongoing in China.

Phase 1 clinical stage

SKB107 (RDC)^[2]: The Phase 1 study is ongoing.

SKB535/MK-6204 (novel ADC with potential FIC target): The Phase 1 clinical trial for SKB535 is ongoing in China.

SKB445 (novel ADC with potential FIC target): The Phase 1 clinical trials for SKB445 is ongoing in China.

SKB105/CR-003 (ITGB6 ADC): In January 2026, an IND application was approved by the CDE of NMPA for the treatment of advanced solid tumor. A Phase 1/2 trial is ongoing in China.

Strategic Layout of Non-DC Assets with Focus on Combination Therapy & Indication Expansion

Drug candidates for oncology

• Tagitanlimab (PD-L1 mAb, also known as A167) (科泰莱^®): In January 2025, the Company received marketing authorization of tagitanlimab used in combination with cisplatin and gemcitabine for the first-line treatment of NPC from NMPA. Tagitanlimab is the first PD-L1 mAb globally to receive authorization for the first-line treatment of NPC.
• In May 2025, the results of a Phase 3 clinical study of tagitanlimab in combination with cisplatin and gemcitabine for the first-line treatment of NPC were presented at the ASCO Annual Meeting.

Cetuximab N01 (EGFR mAb, also known as A140) (达泰莱^®):

• In February 2025, the Company received marketing authorization in China from the NMPA for Cetuximab N01 Injection used in combination with FOLFOX or FOLFIRI regimens for first-line treatment of RAS wild-type mCRC.

Lunbotinib Fumarate Capsules (RET inhibitor, also known as A400/EP0031)(宁泰莱^®)^[3]：

• An NDA was accepted for review by the CDE of the NMPA of China for the 1L+ treatment of RET-fusion positive NSCLC.
• The company is also conducting a Phase 1b/2 clinical study for RET+ MTC and solid tumor in China.
• Ellipses Pharma is progressing their phase 2 clinical study globally outside of China.
• In May 2025, results from the Phase 1 study of Lunbotinib Fumarate Capsules in patients with advanced RET-mutant MTC were presented at the ASCO Annual Meeting.

SKB118/CR-001 (PD-1/VEGF bsAb):

• In January 2026, Crescent Biopharma announced the regulatory clearance of the IND application for SKB118 by FDA to initiate its global ASCEND Phase 1/2 clinical trial for the treatment of advanced solid tumors, and the first patient has been dosed in February, 2026.
• The company is planning to initiate the Phase 1/2 clinical study for SKB118 in China in the first half of 2026.

Drug candidates for autoimmune diseases

SKB378/WIN378 (TSLP mAb):

• In January 2025, an IND application for SKB378 for the treatment of COPD was approved by the NMPA.
• Its collaboration partner, Windward Bio, has launched the Phase 2 POLARIS global trial in patients with asthma.

SKB575 (TSLP/undisclosed target bsAb): In March 2026, an IND application for SKB575 for the treatment of atopic dermatitis was approved by the NMPA.

Drug candidates for other non-oncology diseases

SKB336 (FXI/FXIa mAb): The company completed Phase 1 clinical trial in China.

Multiple Products First Included in National Reimbursement Drug List with Accelerated Market Coverage 

In 2025, the Company witnessed an explosive growth in the commercialization of its innovative achievements. The Company has also filed an NDA for Lunbotinib Fumarate Capsules and expects to commence its commercialization in the second half of 2026 or the first half of 2027, subject to regulatory communications and marketing approval. To date, the company's initial commercial product portfolio, consisting of five products, has taken shape.

Supported by national innovation policies, the Company has successfully secured the first-time inclusion of three of its commercialized products, namely 佳泰莱^®, 科泰莱^® and 达泰莱^®, in the National Reimbursement Drug List (國家醫保藥品目錄), which officially took effect on January 1, 2026, and is expected to benefit more patients faster and better.

Steady Advancement of Global Collaboration and Comprehensive Strength Authoritatively Recognized

Collaboration with MSD: As at the date of this announcement, MSD is evaluating initiated 17 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other agents for several types of cancer, including BC, LC, gynecological cancers, GI cancer and GU cancer. In addition to sac-TMT, the company is also collaborating with MSD on certain ADC assets to continuously explore favorable ADC pipeline portfolios.

Collaboration with Ellipses Pharma: The Company has deepened its collaboration with Ellipses Pharma on A400/EP0031, which has cleared by the FDA to progress into Phase 2 clinical development. As at December 31, 2025, a total of 39 clinical sites in the United States, Europe and UAE were set up for Lunbotinib Fumarate Capsules.

Collaboration with Windward Bio: In January 2025, the Company and Harbour BioMed had entered into an exclusive license agreement with Windward Bio, under which the Company and Harbour BioMed granted Windward Bio an exclusive license for the research, development, manufacturing and commercialization of SKB378/WIN378 globally (excluding Greater China and several Southeast and West Asian countries). Windward Bio has launched the Phase 2 POLARIS global trial in patients with asthma.

Collaboration with Crescent Biopharma. In December 2025, the company and Crescent Biopharma entered into a strategic collaboration for SKB105/CR-003 and SKB118 (a PD1 x VEGF bsAb, also known as CR-001). Under the collaboration, the company granted Crescent Biopharma exclusive rights to research, develop, manufacture and commercialize SKB105/CR-003 in the United States, Europe and all other markets outside of Greater China. In return, the compamy obtained exclusive rights from Crescent Biopharma to research, develop, manufacture and commercialize SKB118/CR-001 in Greater China.

In January 2026, Crescent Biopharma announced the regulatory clearance of the IND application for SKB118 by FDA to initiate its global ASCEND Phase 1/2 clinical trial for the treatment of advanced solid tumors, and the first patient has been dosed in February, 2026.

Continuous Improvement of ESG Capabilities to Consolidate the Foundation for Sustainable Development

Through the establishment and continuous improvement of the ESG governance structure, the Company comprehensively enhances ESG performance ability and ensures the Company's sustainable development. In May 2025, the company was awarded "Best ESG" by Extel. In March 2026, the Company had received a rating of "AA" in the MSCI ESG Rating Assessment.

Outlook

In 2026, Kelun-Biotech will continue to drive innovation and strengthen its operational capabilities, steadily advancing towards becoming a world-class biopharmaceutical company. Specifically, the Company will implement the following development strategies: advancing differentiated pipelines targeting indications with significant medical needs; innovating on and optimizing payload-linker strategies and novel DC designs and structures, while expanding applications in non-oncology diseases; enhancing its end-to-end drug development and commercialization capabilities; expanding business landscape and strategic partnerships and improve our capabilities for the development, registration and commercialization of our products in ex-China market; and optimizing its operational systems with the aim of becoming a leading global biopharmaceutical company.

About Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.

Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (referred to as "Kelun-Biotech" Stock Code: 6990.HK) is a subsidiary of Sichuan Kelun Pharmaceutical Co., Ltd., specializing in the R&D, manufacturing, commercialization, and global collaboration of innovative biological drugs and small molecule drugs. The Company focuses on addressing unmet clinical needs both globally and in China, with a strategic emphasis on major disease areas such as oncology, autoimmune disorders, and metabolic diseases. It is dedicated to building an international platform for drug R&D and industrialization, with the aim of becoming a global leader in the innovative drug sector. Currently, Kelun-Biotech has over 30 key innovative drug projects, including 4 projects covering 8 indications that have received market approval, 1 project at the NDA stage, and more than 10 projects in clinical trials. The Company has also successfully established its internationally renowned proprietary ADC and novel conjugated drug platform, OptiDC^TM, with 2 ADC projects covering 5 indications approved for market launch, and several ADC or novel conjugated drug projects in clinical or preclinical development.

CHENGDU, China, March 18, 2026 /PRNewswire/ -- The 2026 European Lung Cancer Congress (ELCC) will be held in Copenhagen, Denmark, from March 25 to 28, 2026 (local time). At this congress, the final OS analysis from the pivotal study (OptiTROP-Lung03) of sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®), a TROP2 ADC developed by Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK), has been selected as a Late-Breaking Abstract (LBA) (Presentation Number: LBA4). Professor Yunpeng Yang from the Sun Yat-sen University Cancer Center will present the findings to the global research community during a Mini Oral Session. The abstract was published on the ESMO Open.

The OptiTROP-Lung03 study was designed to evaluate the efficacy and safety profile of sac-TMT monotherapy (5 mg/kg every other week) versus docetaxel for the treatment of patients with locally advanced or metastatic EGFR-mutant NSCLC who have previously treated  with an EGFR-TKI and platinum-based chemotherapy. Previously reported results presented at the ASCO 2025 meeting in 137 randomized participants demonstrated that sac-TMT achieved statistically significant and clinically meaningful improvements in progression-free survival (PFS) and overall survival (OS) compared to docetaxel——the hazard ratio (HR) for BICR-assessed PFS was 0.30 (95% CI: 0.20–0.46, one-sided p<0.001) and HR for OS was 0.49 (95% CI: 0.27–0.88, one-sided p=0.007)^[1]. Based on these positive results, sac-TMT received approval from the National Medical Products Administration (NMPA) for this indication, which has also been included in China's National Reimbursement Drug List (NRDL).

At the 2026 ELCC, the final OS analysis, along with updated PFS and additional data from the OptiTROP-Lung03 study will be presented. As of December 11, 2025, the median follow-up was 23.8 months. Key highlights are as follows:

• In the docetaxel control group, 41.3% of patients crossed over to receive sac-TMT after disease progression.
• Considering the impact of OS from crossover treatment in the control group, adjusted and analysed by the pre-specified rank-preserving structural failure time (RPSFT) model, the median OS was 20.0 months in the sac-TMT group vs 11.2 months in the docetaxel group (HR 0.45, 95% CI: 0.28–0.73), with 18-month OS rate of 54.7% vs 9.1%. Without adjustment for subsequent sac-TMT treatment in the control group, median OS was 20.0 months vs 13.5 months (HR 0.63, 95% CI: 0.40–0.98).
• Median PFS assessed by investigators (INV) was 7.9 months vs 2.8 months (HR 0.23, 95% CI: 0.15-0.35).

Notably, based on another study, the OptiTROP-Lung04 study, sac-TMT has been approved by the NMPA for the treatment of advanced or metastatic EGFR-mutant NSCLC after progression on EGFR-TKI therapy, with the findings concurrently published in The New England Journal of Medicine^[2]. In this study among the EGFR-mutant NSCLC population who have progressed after prior EGFR-TKI and platinum-based chemotherapy, sac-TMT demonstrated a statistically significant and clinically meaningful increase in overall survival，with a median OS of 20 months. The consistent positive findings from two pivotal registrational studies further reinforce sac-TMT's leading position in the treatment landscape for pre-treated EGFR-mutant NSCLC, offering a more definitive and long-term survival benefit option for patients with advanced lung cancer.

About Sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) BC who have received prior ET and at least one line of chemotherapy in advanced setting. The first two indications listed above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinical benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing Phase III global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.