Agios Pharmaceuticals’ sickle cell disease candidate didn’t prove any better than Novo Nordisk’s investigational PK activator or the biopharma’s own asset that is currently under FDA review for the indication.
Agios Pharmaceuticals is discontinuing its next-generation PK activator after midstage data in sickle cell disease failed to differentiate the asset from others in development, including Agios’ own mitapivat and Novo Nordisk’s etavopivat.
The axed candidate, dubbed tebapivat, was evaluated in a Phase 2 study of 59 patients with sickle cell disease (SCD) who were 16 years and older. At 12 weeks, daily doses of the oral drug were tied to a hemoglobin response—the study’s primary endpoint—for 43.8% of patients receiving 2.5 mg, 47.1% at 5 mg and 29.4% of patients receiving 7.5 mg, compared to 33.3% in the placebo arm.
The findings fail to reflect a dose response and missed Agios’ bar for continued development in SCD, according to a company release shared Tuesday. The asset isn’t currently being tested in any other indications, according to Agios’ online pipeline.
Meanwhile, Novo Nordisk’s investigational once-daily PK activator etavopivat led to a hemoglobin response in 48.7% of patients in the Phase 3 SCD trial HIBISCUS after 24 weeks, according to data released earlier this year. Etavopivat also elicited a 27% drop in vaso-occlusive crises. At the time, Novo said it planned to submit the drug for FDA approval in the second half of this year.
Analysts were largely unruffled by the discontinuation, with Leerink Partners writing Tuesday that the firm didn’t include tebapivat in its model, so that remains unchanged.
The discontinuation does put more pressure on Agios’ other assets, namely mitapivat, an oral PK activator that is currently under FDA review for SCD. In a Phase 3 trial, mitapivat demonstrated a hemoglobin response rate of 40.6%.
Given its priority review status and accelerated approval pathway, the FDA expects to make a decision on the candidate on or before Nov. 1. Agios said the fresh tebapivat findings don’t change its conviction in mitapivat’s SCD opportunity, according to Leerink Partners.
Mitapivat is already marketed in two other indications: as Pyrukynd for pyruvate kinase deficiency and Aqvesme for anemia in patients with alpha- or beta-thalassemia.
“We believe the update places greater importance on the commercial execution of mitapivat in thalassemia, a smooth regulatory review for mitapivat in SCD, the early pipeline (e.g., AG-181 in phenylketonuria, AG-236 in polycythemia vera), and any potential business development opportunities,” Leerink wrote.
Analysts at Truist agreed, writing Tuesday that tebapivat had held the potential to serve as a “narrative enricher for longer-term franchise durability.
“The discontinuation does remove AGIO’s second shot on goal in SCD, and puts more concentration risk on mitapivat, which to us could be relevant at a time when the bar for differentiation in the class continues to rise, with Novo Nordisk’s QD etavopivat (PK activator comp) bringing a strong showing in the ph. 3 HIBISCUS study,” Truist said.
