FDA Grants Orphan Drug Designation to Mitapivat for Treatment of Thalassemia

Mitapivat is an investigational, oral, small molecule allosteric activator of wild-type and a variety of mutated PKR enzymes that is not yet approved by the FDA.

The FDA has granted orphan drug designation to Agios Pharmaceuticals’ first-in-class pyruvate kinase-R (PKR) activator mitapivat for the treatment of patients with thalassemia. Mitapivat is an investigational, oral, small molecule allosteric activator of wild-type and a variety of mutated PKR enzymes that is not yet approved by the FDA.

Thalassemia is a serious hemolytic anemia with limited treatment options, according to Chris Bowden, MD, chief medical officer at Agios.

The FDA’s Office of Orphan Drug Products grants orphan status to support the development of medicines for underserved patient populations or rare disorders that affect fewer than 200,000 people in the United States.

Orphan drug designation provides certain benefits, including market exclusivity upon regulatory approval, if received, and exemption of FDA application fees and tax credits for qualified clinical trials.

Agios is conducting a phase 2 study evaluating the efficacy, safety, pharmacokinetics, and pharmacodynamics of treatment with mitapivat in adults with non-transfusion-dependent β- and α-thalassemia (NTDT). The trial is fully enrolled, and the primary endpoint is hemoglobin response.

Preliminary phase 2 data establishing proof-of-concept for mitapivat in thalassemia were disclosed at the end of 2019. The company plans to present updated data from its phase 2 study of mitapivat in both alpha- and beta-thalassemia patients at the virtual European Hematology Association Annual Congress, June 11-14, 2020.

In addition, Agios has 2 ongoing global, pivotal trials in adults with PK deficiency that are fully enrolled.

ACTIVATE: A placebo-controlled trial with a 1:1 randomization evaluating patients who do not receive regular transfusions. The primary endpoint of the trial is the proportion of patients who achieve a sustained hemoglobin increase of ≥1.5 g/dL.
ACTIVATE-T: A single arm trial of regularly transfused patients with a primary endpoint of reduction in transfusion burden over 6 months compared to individual historical transfusion burden over prior 12 months.

Mitapivat is also being studied in sickle cell disease under a Cooperative Research and Development Agreement (CRADA) with the U.S. National Institutes of Health.

REFERENCE

Agios Announces FDA Orphan Drug Designation Granted to Mitapivat for Treatment of Thalassemia [news release]. Cambridge, MA; June 8, 2020: Agios. [email] Accessed June 8, 2020.