Agios Provides Update on Phase 2 Trial of Tebapivat in Sickle Cell Disease

• Hemoglobin response rates for tebapivat, a PK activator, were consistent with the class of medicine, but Phase 2 results did not establish a differentiated profile to support continued development in sickle cell disease
• Safety and tolerability of tebapivat were consistent with prior sickle cell disease trials
• sNDA for mitapivat, company’s foundational PK activator, is under FDA Priority Review in sickle cell disease; PDUFA goal date is November 1, 2026

CAMBRIDGE, Mass., July 21, 2026 — Agios Pharmaceuticals, Inc. (Nasdaq: AGIO), a commercial-stage biopharmaceutical company focused on delivering innovative medicines for patients with rare diseases, today announced topline results from the Phase 2 trial of tebapivat, an oral pyruvate kinase (PK) activator, in patients aged 16 years or older with sickle cell disease.

The Phase 2 trial was designed to characterize the dose-response relationship of tebapivat in sickle cell disease and evaluate whether its profile was meaningfully differentiated relative to other PK activators. The trial included a 12-week, double-blind, placebo-controlled period in which 59 participants were randomized 2:2:2:1 to receive one of three once-daily (QD) tebapivat doses (2.5 mg, 5.0 mg, or 7.5 mg) or placebo.

Over the 12-week treatment period, improvements in hemoglobin levels and hemolysis were observed across all tebapivat dose levels, consistent with the established PK activation mechanism. The trial’s primary endpoint of hemoglobin response (≥1.0 g/dL increase in average hemoglobin concentration from Weeks 10 through 12 compared with baseline) was achieved by 43.8% (n=7/16), 47.1% (n=8/17), and 29.4% (n=5/17) in the 2.5 mg QD, 5.0 mg QD, and 7.5 mg QD tebapivat arms, respectively, and 33.3% (n=3/9) in the placebo arm. The safety and tolerability of tebapivat in the Phase 2 trial were consistent with that observed in prior sickle cell disease trials. The trial did not demonstrate the level of differentiation required to support continued development; therefore, Agios has decided not to advance tebapivat in sickle cell disease.

“These Phase 2 data further reinforce PK activation as a clinically validated mechanism in sickle cell disease, with tebapivat demonstrating hematologic activity consistent with this class of medicine. However, the results did not establish the level of differentiation we believe is necessary to support continued development,” said Sarah Gheuens, M.D., Ph.D., Chief Medical Officer and Head of R&D, Agios. “We remain focused on mitapivat, our foundational PK activator, which is under FDA Priority Review in sickle cell disease with an expected U.S. approval later this year. We look forward to bringing this first-in-class medicine to the sickle cell community and building on the extensive clinical experience generated to date as we work to address the significant unmet need in this debilitating disease.”

Earlier this month, Agios announced that the U.S. Food and Drug Administration (FDA) accepted its supplemental New Drug Application (sNDA) for the accelerated approval of mitapivat, an oral PK activator, in sickle cell disease with a Priority Review. The Prescription Drug User Fee Act (PDUFA) goal date for this sNDA is November 1, 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]