Here's Why Shares in Novo Nordisk Rival, Agios Pharmaceutical, Soared This Week

Agios Pharmaceuticals (NASDAQ: AGIO) stock rose by 13.8% during the week through Friday morning. It's a move driven by the Food and Drug Administration's (FDA) announcement that it would grant priority review for Agios' key drug, an oral pyruvate kinase (PK) activator, mitapivat, in sickle cell disease (SCD).

Agios and mitapivat

Mitapivat is already approved to treat PK deficiency and thalassemia in adults, and Agios is seeking approval as the first oral pyruvate kinase (PK) activator for sickle cell disease. PK activators work to improve the health of red blood cells and reduce sickle cell formation, resulting in a reduction in blood vessel blockages, anemia, and the sickle cell pain crises (SCPCs), events that create severe discomfort for sufferers.

Mitapivat trial results

It's here where it gets a bit complicated. In November, management released mixed results from the Phase 3 RISE UP trial of mitapivat in SCD.

• The primary endpoint, hemoglobin response, and the key secondary endpoint, change from baseline in hemoglobin concentration, were met.
• Mitapivat did "not meet statistical significance in the primary endpoint of annualized rate of SCPCs."

The failure to meet the primary endpoint of SCPC reduction is an obvious concern, especially given that Novo Nordisk later reported that its rival oral pyruvate kinase-R (PKR) activator improved hemoglobin response and demonstrated a statistically meaningful reduction in crisis events.

Fast forward to June, and Agios provided more detailed data from the RISE UP trial, noting that among patients in the mitapivat-treated group who reported a response in hemoglobin, there was a "clinically meaningful benefit across measures of sickle cell pain crises, fatigue, and other patient-reported outcomes."

Image source: Getty Images.

Where next for Agios Pharmaceuticals

An accelerated approval (decision due by Nov. 1) would be a major plus. Still, to gain full approval later, Agios has to demonstrate success in the confirmatory REIGNITE 3 trial, which the FDA requires as part of the accelerated approval process.

There's still plenty for Agios to do, and competition is coming from a formidable rival, but Agios appears to have good chances of getting mitapivat approved for SCD this year.

Lee Samaha has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Novo Nordisk. The Motley Fool has a disclosure policy.