US FDA approves treatment for anaemia in adults with rare inherited disorder

FDA has approved Pyrukynd (mitapivat) tablets to treat hemolytic anaemia in adults with Pyruvate Kinase (PK) deficiency, the health regulator notified in a statement.

The statement informed that the effectiveness of Pyrukynd was evaluated in two studies. One was a randomised, double-blind, placebo-controlled clinical study of 80 adults with PK deficiency who did not receive regular blood transfusions. The other was a single-arm study of 27 adults with PK deficiency who received regular blood transfusions. In these studies, patients received Pyrukynd up to 50 mg orally twice daily after an initial dose titration (adjustment) period. Participants received Pyrukynd for an average duration of about 24 weeks in the randomised study and an average duration of about 40 weeks in the single-arm study.

In the randomised study, the effectiveness of Pyrukynd was based upon haemoglobin response defined as a 1.5 g/dL or greater increase in haemoglobin concentration from the beginning of the study that was sustained at two or more scheduled assessments. At the end of the study, 40 per cent of participants receiving Pyrukynd had a haemoglobin response compared with no participants receiving placebo, the statement added.

In the single-arm study, effectiveness was based on reduction in transfusion burden, defined as at least a 33 per cent reduction in the number of red blood cell units transfused during the last 24 weeks of treatment compared with the historical transfusion burden on the individual participant (standardised to 24 weeks). Thirty-three percent of participants who received Pyrukynd met this reduction in transfusion burden, including 22 per cent of participants who did not require any transfusions over the last 24 weeks of treatment, it further noted.

This application received orphan drug designation, fast track designation, and priority review, concluded the statement.