Agios Pharmaceuticals (Nasdaq: AGIO) reported Thursday that tebapivat failed to meet its predefined advancement threshold in a Phase II trial for lower-risk myelodysplastic syndromes. The news closes the door on that indication for the oral pyruvate kinase activator, meaning that hopes now rest on the molecule's ongoing development for sickle cell disease.
The Phase IIb study was an open-label, multicenter, dose-finding trial that enrolled 65 patients with LR-MDS and anemia — a heavily pretreated, heterogeneous population — and evaluated tebapivat at 10 mg, 15 mg, and 20 mg once daily over 24 weeks. The primary endpoint was transfusion independence, defined as eight consecutive weeks without a transfusion during the treatment period. Agios said tebapivat showed evidence of biological activity but that clinical benefit was not observed in a sufficient proportion of patients, or any identifiable subgroup, to clear the company's internal bar for further development. No specific response rates were disclosed. On safety, tebapivat was well tolerated across all dose levels with no new signals identified — a finding that offers little consolation given the efficacy outcome, but preserves the molecule's profile for its ongoing sickle cell program.
Tebapivat is structurally differentiated from Bristol Myers Squibb's Reblozyl (luspatercept), the erythroid maturation agent approved in LR-MDS, by its mechanism: dual activation of the PKR and PKM2 isoforms of pyruvate kinase, targeting red blood cell energy metabolism rather than TGF-β signaling. Whether that mechanistic distinction could have translated to a complementary or superior clinical profile in MDS now goes untested at scale. Agios said topline data from the Phase II sickle cell disease trial are expected in the second half of 2026, which now represents the molecule's sole remaining clinical pathway.
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