FDA Panel Backs Approval of Deferiprone for Iron Overload

Yael Waknine

September 16, 2011

September 16, 2011 — The US Food and Drug Administration (FDA)'s Oncologic Drugs Advisory Committee has voted 10-2 in support of accelerated approval for second-line use of the iron chelator deferiprone (Ferriprox film-coated tablets; ApoPharma, Inc) in patients with transfusional hemosiderosis. The application will now go to the full FDA for consideration, with a decision expected by October 14, 2011.

"We are very pleased that [the committee] members responded positively to the totality of the clinical data and to [deferiprone]'s established track record," said Michael Spino, MD, president of ApoPharma in a company news release. "If approved, this drug will provide a critically important new treatment option to individuals whose current chelation is inadequate."

As part of the documentation, the company submitted data from study LA36-0310, a retrospective analysis of existing data pooled from previous safety and efficacy of deferiprone in patients with transfusion-related hemosiderosis refractory to chelation.

Findings represented 34,000 patient-years of exposure over more than a decade and primarily included patients with thalassemia; other underlying diagnoses included sickle cell disease and myelodysplastic syndrome.

Results for the intent-to-treat population showed that 52% of patients administered 75 to 100 mg/kg deferiprone daily achieved a 20% decrease in serum ferritin at 1 year (95% confidence interval [CI], 45% - 58%; 4416 ± 2288 to 3453 ± 2099 µg/L; P < .0001), representing the primary endpoint; 49% had a 20% decrease in liver iron concentration (95% CI, 33% - 51%); and 62% had a 20% decrease in cardiac iron concentration (95% CI, 45% - 77%).

There were 231 serious adverse events recorded in the various trials. Sixty of those incidents led to discontinuation. Agranulocytosis was the most clinically significant serious adverse event and occurred in 1.7% of patients.

According to the news release, the company has proposed to introduce an education program similar to that available in Europe in order to mitigate the potential risks of deferiprone therapy.

Approved in Europe in 1999 and used in 61 countries worldwide, deferiprone is indicated for treating iron overload in patients with thalassemia major when deferoxamine is contraindicated or inadequate.

Iron chelators currently approved by the FDA include subcutaneous deferoxamine infusion (Desferal, Novartis Pharmaceuticals Corp) and deferasirox tablets for oral suspension (Exjade, Novartis).