FDA Plans to Rescind Breakthrough Therapy Designation for Protagonist’s PV Therapy

Shares of Protagonist Therapeutics fell more than 20 percent after the company said that the U.S. Food and Drug Administration notified it that it plans to rescind the Breakthrough Therapy designation for rusfertide in polycythemia vera, a rare blood cancer.

The company said it has requested a meeting with the FDA and submitted a briefing document explaining why the company believes rusfertide continues to warrant Breakthrough Therapy designation. Rusfertide is being developed to reduce erythrocytosis in those polycythemia vera (PV) patients who do not require further treatment for thrombocytosis and/or leukocytosis.

Breakthrough Therapy Designation requires that the drug candidate treat a serious or life-threatening disease or condition. It also requires preliminary clinical evidence that indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints. The designation has the potential to expedite the development and regulatory review process.

Protagonist revealed the news in a filing with the U.S. Securities and Exchange Commission. The FDA notification does not relate to the rusfertide Fast Track designation, which remains active.

The company has initiated a phase 3 study of rusfertide in polycythemia vera and no changes to the development plan or timeline are anticipated at this stage.

Author: Rare Daily Staff