Live from ASCO 2024 | Ascentage Pharma Releases Updated Data Showing Promising Efficacy and Safety of Lisaftoclax in Patients with WM

SUZHOU, China, and ROCKVILLE, Md., June 5, 2024 /PRNewswire/ -- Ascentage Pharma (6855.HK), a global biopharmaceutical company engaged in developing novel therapies for cancer, chronic hepatitis B (CHB), and age-related diseases, announced today that it has released updated results from a global, multicenter Phase Ib/II study of the Bcl-2 inhibitor lisaftoclax (APG-2575) alone or in combinations for the treatment of patients with Waldenström macroglobulinemia (WM), in a poster presentation at the 60th American Society of Clinical Oncology (ASCO) Annual Meeting taking place in Chicago, IL. This is the second consecutive year in which this study of lisaftoclax, a key drug candidate in the company's apoptosis-targeted pipeline, was selected for presentations at the ASCO Annual Meeting.

The ASCO Annual Meeting showcases the most cutting-edge research in clinical oncology and state-of-the-art advanced cancer therapies and is the world's most influential and prominent scientific gathering of the clinical oncology community. Presenting clinical development progress at the ASCO Annual Meeting for the seventh consecutive year, Ascentage had four clinical studies of three of the company's proprietary drug candidates selected for presentations, including an oral report, at ASCO 2024.

The latest results from this clinical study validated the favorable safety and efficacy of lisaftoclax monotherapy and in combinations in WM. According to the data, lisaftoclax combined with ibrutinib showed an objective response rate (ORR) of 90.9% in treatment-naïve patients with WM (responses that were unaffected by the CXCR4 mutation), manageable adverse events (AEs), and a low risk of tumor lysis syndrome (TLS). In addition, no potential drug-drug interactions (DDIs) with ibrutinib were observed in the study.

"Lisaftoclax is a novel Bcl-2 selective inhibitor developed to treat malignancies by selectively blocking the antiapoptotic protein Bcl-2 and hence restoring the normal apoptosis process in cancer cells," said  Dr. Sikander Ailawadhi, the Principal Investigator of the Study from Mayo Clinic. "In this global Phase Ib/II study in patients with relapsed/refractory (R/R) WM, lisaftoclax both as a monotherapy and in combination with ibrutinib or rituximab has shown favorable efficacy that was not negatively affected by the presence of the CXCR4 mutation. In addition, lisaftoclax showed a manageable safety profile with low risk of TLS during daily dose ramp-up. We look forward to seeing more data from this trial."

"Lisaftoclax is the first pivotal-stage Bcl-2 inhibitor in China and the second globally that has demonstrated promising efficacy," said Dr. Yifan Zhai, Chief Medical Officer of Ascentage Pharma. "The updated clinical data of lisaftoclax in WM presented at this year's ASCO Annual Meeting underscore the drug's strong therapeutic potential, both as a monotherapy and in combinations, for the treatment of hematologic malignancies. We will continue to advance the clinical development of lisaftoclax with the hope to allow more patients to benefit from the drug as soon as possible."

Highlights of these data presented at ASCO 2024 are as follows:

Updated efficacy and safety results of BCL-2 inhibitor lisaftoclax (APG-2575) alone or combined with ibrutinib or rituximab in patients (pts) with Waldenström macroglobulinemia (WM)

Abstract#: 7078

Session Title: Hematologic Malignancies—Lymphoma and Chronic Lymphocytic Leukemia

Date and Time: June 3, 2024, Monday, 9:00 AM– 12:00 PM (Central Time)

First Author: Masa Lasica, MBBS, FRACP, FRCPA, St Vincent's Hospital, Melbourne, Victoria, Australia.

Highlights:

Background: Lisaftoclax is a novel, oral, highly selective, potent Bcl-2 inhibitor. In an ibrutinib-resistant patient-derived WM xenograft/preclinical model, lisaftoclax combined with ibrutinib has a strong synergistic effect.

Introduction: This was an open-label, multicenter, global Phase Ib/II study designed to evaluate the efficacy, safety, tolerability, and pharmacokinetics (PK) of lisaftoclax monotherapy or in combinations with agents such as ibrutinib/rituximab in patients with WM.

Patient enrollment and methods:

• In this study, patients with WM were enrolled in 3 arms, including Arm A: lisaftoclax monotherapy in patients resistant to or intolerant of prior treatment with Bruton's tyrosine kinase inhibitors (BTKis); Arm B: lisaftoclax combined with ibrutinib in treatment-naïve patients with WM; and Arm C: lisaftoclax combined with rituximab in BTKi-naïve patients with relapsed/refractory WM.
• Lisaftoclax was orally administered once daily in 28-day cycles. Lisaftoclax was gradually escalated from the starting dose of 400 mg to 1,200 mg. As of January 25, 2024, a total of 46 patients were enrolled in the study (Arm A [n=14] at doses of up to 1,000 mg; Arm B [n=24] at doses of up to 1,200 mg; Arm C [n=8] at doses of up to 800 mg).

Efficacy results:

• The median (range) durations of treatment were 11 (1-28), 23.5 (1-34), and 11.5 (5-33) months for Arms A, B, and C, respectively.
• The ORRs (PR, very good partial response [VGPR], CR) were 41.7%, 90.9%, and 37.5% for Arms A, B, and C, respectively.
• In Arm A, patients with wild-type CXCR4 (n =7) had better overall responses to lisaftoclax than the CXCR4 mutation group (n = 3).
• In Arms B and C, no significant differences between patients with/without CXCR4 mutation were observed.

Safety results:

• In Arm B, 1 dose-limiting toxicity (DLT, grade 3 clinical TLS), in the setting of anticipated renal impairment, occurred at 1,200 mg; and 1 grade 3 laboratory TLS, primarily attributed to dehydration and concomitant symptomatic therapies, occurred at 1,000 mg. Abnormal electrolytes was resolved without recurrence after 1 day of drug interruption.
• Grade ≥ 3 lisaftoclax-related AEs included neutropenia (15.2%), thrombocytopenia (4.3%), decreased leukocytes (4.3%), TLS (4.3%), anemia (2.2%), weight loss (2.2%), and septic shock (2.2% in the setting of neutropenia).
• Ventricular arrhythmia was not observed.
• One patient required dose reduction because of neutropenia.
• The maximum-tolerated dose (MTD) was not reached.
• Lisaftoclax combined with ibrutinib showed a PK exposure comparable to lisaftoclax or ibrutinib alone, indicating no potential DDIs.

Conclusions: Lisaftoclax alone or combined with ibrutinib or rituximab was well tolerated and demonstrated measurable effects in patients with treatment-naïve or BTKi-treatment-failed WM.

*Lisaftoclax is an investigational drug that has not been approved in any country and region.

Appendix: The four clinical studies of Ascentage Pharma's three drug candidates, including lisaftoclax, presented at this year's ASCO Annual Meeting.

About Ascentage Pharma

Ascentage Pharma (6855.HK) is a globally focused biopharmaceutical company engaged in developing novel therapies for cancers, chronic hepatitis B, and age-related diseases. On October 28, 2019, Ascentage Pharma was listed on the Main Board of the Stock Exchange of Hong Kong Limited with the stock code 6855.HK.

Ascentage Pharma focuses on developing therapeutics that inhibit protein-protein interactions to restore apoptosis, or programmed cell death. The company has built a pipeline of 9 clinical drug candidates, including novel, highly potent Bcl-2, and dual Bcl-2/Bcl-xL inhibitors, as well as candidates aimed at IAP and MDM2-p53 pathways, and next-generation tyrosine kinase inhibitors (TKIs). Ascentage Pharma is also the only company in the world with active clinical programs targeting all three known classes of key apoptosis regulators. The company is conducting more than 40 Phase I/II clinical trials, including 5 global registrational phase III studies, in the US, Australia, Europe, and China. Ascentage Pharma has been designated for multiple Major National R&D Projects, including five Major New Drug Projects, one New Drug Incubator status, four Innovative Drug Programs, and one Major Project for the Prevention and Treatment of Infectious Diseases.

Olverembatinib, the company's core drug candidate developed for the treatment of drug-resistant chronic myeloid leukemia (CML) and the company's first approved product in China, has been granted Priority Review Designations and Breakthrough Therapy Designations by the Center for Drug Evaluation (CDE) of China National Medical Products Administration (NMPA). To date, the drug had been included into the China 2022 National Reimbursement Drug List (NRDL). Furthermore, olverembatinib has been granted an Orphan Drug Designation (ODD) and a Fast Track Designation (FTD) by the US FDA, and an Orphan Designation by the EMA of the EU. To date, Ascentage Pharma has obtained a total of 16 ODDs from the US FDA and 1 Orphan Designation from the EMA of the EU for 4 of the company's investigational drug candidates.

Leveraging its robust R&D capabilities, Ascentage Pharma has built a portfolio of global intellectual property rights and entered into global partnerships with numerous renowned biotechnology and pharmaceutical companies and research institutes such as UNITY Biotechnology, MD Anderson Cancer Center, Mayo Clinic, Dana-Farber Cancer Institute, MSD, and AstraZeneca. The company has built a talented team with global experience in the discovery and development of innovative drugs and is setting up its world-class commercial manufacturing and Sales & Marketing teams. One pivotal aim of Ascentage Pharma is to continuously strengthen its R&D capabilities and accelerate its clinical development programs, in order to fulfil its mission of addressing unmet clinical needs in China and around the world for the benefit of more patients.

Forward-Looking Statements

The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law, Ascentage Pharma undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events, or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article, statements of, or references to, our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development.