Deferiprone is approved as a second-line treatment for transfusional iron overload when the condition has not been resolved by chelation therapy in patients with thalassemia, the Food and Drug Administration announced Oct. 14.
The new agent will be marketed as Ferriprox by ApoPharma. The FDA said the Toronto-based company has agreed to several postmarketing requirements and commitments, including further study in patients who have transfusional iron overload after treatment for sickle cell disease.
The FDA’s Oncologic Drugs Advisory Committee recently voted 10-2 that treatment with deferiprone had a favorable benefit-risk profile for treatment of patients with transfusional iron overload when current chelation therapy is inadequate.
As the decision date approached, however, the consumer advocacy group Public Citizen announced that it had sent the FDA a letter opposing approval. Public Citizen contended that APO Pharma had failed to demonstrate the drug is safe and effective in its intended population. The group noted that the FDA had refused to approve deferiprone in 2009 without an additional prospective, randomized, controlled study, but that no such study had been conducted.
"Ferriprox represents the first new FDA-approved treatment for this disorder since 2005."
The FDA announcement said its decision on safety and effectiveness was based on 12 clinical studies in which participating patients had not responded to prior iron chelation therapy.
"Ferriprox was considered a successful treatment for patients who experienced at least a 20% decrease in serum ferritin, a protein that stores iron in the body for later use. Half of the patients in the study experienced at least a 20% decrease in ferritin levels," the agency said.
Thalassemia is a genetic blood disorder that causes anemia. It is treated with frequent blood transfusions, but these can lead to excess iron in the body, a serious, potentially fatal condition. Chelation therapy, a process in which chemical agents remove heavy metals from the body, is the standard of care for transfusional iron overload.
"Ferriprox represents the first new FDA-approved treatment for this disorder since 2005," Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in the FDA announcement.
Deferoxamine (Desferal), an iron chelator administered via a subcutaneous infusion pump (usually 6 nights a week), was approved in 1968, and deferasirox (Exjade), an oral chelator, in 2005. The new agent was approved in Europe in 1999, but had not been able to secure a U.S. go-ahead until the current "accelerated approval."
Ferriprox’s most common side effects have included nausea, vomiting, abdominal and joint pain, chromaturia, neutropenia, and "an increase in the level of a liver enzyme that may be indicative of tissue or liver damage at unsafe amounts," according to the FDA.
The agency said the most serious side effect was the development of agranulocytosis in about 2% of patients treated with Ferriprox.