Agios Provides Update on Phase 2b Trial of Tebapivat in Lower-Risk Myelodysplastic Syndromes

• Results did not meet predefined threshold to support further development in LR-MDS
• Tebapivat was well tolerated, with no new safety signals observed

CAMBRIDGE, Mass., May 29, 2026 — Agios Pharmaceuticals, Inc. (Nasdaq: AGIO), a commercial-stage biopharmaceutical company focused on delivering innovative medicines for patients with rare diseases, today announced that it will not advance tebapivat, a next-generation oral pyruvate kinase (PK) activator, in lower-risk myelodysplastic syndromes (LR-MDS). This decision follows results from its Phase 2b trial that did not meet the company’s predefined threshold to support further development in this indication.

The open-label, multicenter, 24-week dose-finding trial evaluated once-daily tebapivat at 10 mg, 15 mg, and 20 mg in 65 patients with LR-MDS and anemia, representing a heavily pretreated, heterogeneous population. The primary endpoint was transfusion independence, defined as eight consecutive weeks without a transfusion during the 24-week treatment period. While tebapivat demonstrated evidence of biological activity, clinical benefit was not observed in a sufficient proportion of patients or subgroup of patients to meet the company’s predefined threshold for advancement in LR-MDS. Tebapivat was well tolerated across all dose levels, with no new safety signals identified.

“The results from the Phase 2b trial underscore the biological complexity of lower-risk myelodysplastic syndromes and the challenges of identifying patients most likely to benefit. On behalf of the entire Agios team, I want to extend our sincere gratitude to the patients, caregivers, investigators, and broader community who made this research possible,” said Sarah Gheuens, M.D., Ph.D., Chief Medical Officer and Head of R&D, Agios. “PK activation remains a clinically validated mechanism, and we continue to see significant potential for tebapivat as a next-generation medicine in sickle cell disease. We look forward to sharing topline data from this Phase 2 trial in the second half of 2026.”

About Tebapivat

Tebapivat is a next-generation oral pyruvate kinase (PK) activator designed to provide optimized clinical benefits for patients with rare hematologic diseases. It is structurally differentiated by its potent dual activation of the PKR and PKM2 isoforms (or variants) of the PK enzyme, which are expressed in red blood cells. Clinical pharmacology data supports once-daily dosing of tebapivat, without the need for a dose taper. Tebapivat is currently being evaluated in a Phase 2 trial for the treatment of sickle cell disease, with topline data anticipated in the second half of 2026.

About Agios: Fueled by Connections to Transform Rare Diseases™

At Agios, our vision is to redefine the future of rare disease treatment. Fueled by connections, we build trusted partnerships with communities – collaborating to develop and deliver innovative medicines that have the potential to transform lives. With a foundation in hematology, we combine biological expertise with real-world insights to advance a growing pipeline of rare disease medicines that reflect the priorities of the people we serve. Agios is a commercial-stage biopharmaceutical company headquartered in Cambridge, Massachusetts. To learn more, visit www.agios.com and follow us on LinkedIn and X.

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Contacts

Investor Contact Morgan Sanford, Vice President, Investor Relations Agios Pharmaceuticals [email protected]

Media Contact

Eamonn Nolan, Senior Director, Corporate Communications Agios Pharmaceuticals [email protected]