• RB042 Phase 1 trial advances into multiple ascending dose study cohorts, demonstrating safety and tolerability to date.
• Dr. Coulie brings more than 25 years of international biopharma leadership and deep expertise in pulmonary disease to the Atisama Board of Directors.

MELBOURNE, Australia, May 15, 2026 /PRNewswire/ -- Atisama Therapeutics (formerly Rage Bio) ("Atisama" or the "Company"), an Australian clinical-stage biotechnology company developing novel splice-switching oligonucleotide (SSO) therapeutics for chronic inflammatory disease, today reported progress in the Phase 1 study of its lead candidate, RB042, and announced the appointment of Dr. Bernard Coulie as Chair of the Board of Directors.

RB042 Phase 1 Clinical Update
The RB042 Phase 1 study (RB042_1001; NCT07285122), evaluating RB042 in healthy volunteers and healthy smokers, has advanced to multi-dose ascending (MAD) cohorts, and continues to demonstrate safety and tolerability. Three of four single ascending dose (SAD) cohorts are complete, and the first MAD cohort has been initiated, with higher-dose cohorts expected to readout in H2 2026.

"RB042 clinical progress is tracking to plan. Safety and tolerability across three SAD cohorts have supported advancement into MAD dosing. Higher-dose cohorts may provide early insights into target engagement to inform future development, with readouts expected later this year," said Dr. Ed Tucker, Chief Medical and Development Officer.

Appointment of Bernard Coulie as Chair of the Board
Dr. Coulie joins Atisama at a pivotal moment, as RB042 advances through early clinical development and the Company prepares for its next phase of growth.

Dr. Coulie currently serves as President and CEO of Pliant Therapeutics (NASDAQ: PLRX), a clinical-stage biopharmaceutical company focused on the development of integrin-based therapies, and holds board positions at several global biotech companies. His career includes senior executive roles at Johnson & Johnson and Actogenix. He has founded and led companies across a range of therapeutic areas, with particular expertise in pulmonary disease, directly relevant to Atisama's lead clinical programme.

As Chair, Dr. Coulie brings deep governance experience and operational leadership to the Atisama Board, with clinical, scientific and commercial acumen that aligns directly with the Company's mission.

"Bernard brings exactly the strategic depth and governance experience we need as we scale and advance our pipeline toward later-stage clinical development. His track record in pulmonary disease, his experience building companies, and his strong relationships across the global investment community make him an exceptional addition to our Board. We are delighted to welcome him," said Dr. Siro Perez, Chief Executive and Scientific Officer.

"Atisama is working on a genuinely differentiated scientific approach to one of the most important unmet needs in respiratory medicine. The biology is compelling, the team is strong, and the clinical progress to date is highly encouraging. I am excited to join the Board and to support the Company as it moves through the clinic and into its next chapter," said Dr. Bernard Coulie, Chair of the Board.

About Atisama Therapeutics
Atisama Therapeutics Pty Ltd (ACN 640 194 770, formerly Rage Bio Pty Ltd) is a clinical-stage biotechnology company developing novel splice-switching oligonucleotide (SSO) therapies for inflammatory disease. Founded on the principle of restoring molecular balance for lasting health, the Company's SSO platform is producing drug candidates that down-regulate disease-driving isoforms and upregulates their protective counterparts; a dual-action mechanism unique to the SSO modality. Atisama's lead asset, RB042, is an inhaled SSO currently in Phase 1 clinical development. Atisama has several other programmes leveraging the novel SSO platform. The Company is headquartered in Melbourne, Australia.

About RB042
RB042 is an inhaled splice-switching oligonucleotide (SSO) targeting the Receptor for Advanced Glycation End-products (RAGE), a genetically validated driver of inflammation in chronic obstructive pulmonary disease (COPD). RB042 redirects pre-mRNA expression to the protective soluble esRAGE isoform over pro-inflammatory membrane-bound mRAGE, potentially shifting the isoform balance disrupted in disease. RB042 is currently being evaluated in a Phase 1 study (RB042_1001; NCT07285122) in healthy volunteers and healthy smokers across single ascending dose and multiple ascending dose cohorts. COPD affects approximately 400 million people globally and is the third leading cause of death; approximately 70% of patients are non-eosinophilic and lack a targeted therapeutic option. RB042 is being developed across all COPD endotypes, with additional indications under evaluation.

For more information, visit www.atisama.com or contact media@atisama.com.