FDA Partially Rescinds Indications for BeneFIX and Ixinity

Owing to conflicting market exclusivity rights, the U.S. Food and Drug Administration (FDA) has partially rescinded its decision to approve BeneFIX and Ixinity for additional indications both therapies received last year for the treatment of hemophilia B, according to the National Hemophilia Foundation.

Pfizer’s BeneFIX and Aptevo Therapeutics’ Ixinity are man-made (recombinant) forms of factor IX (FIX), the blood-clotting protein that is missing or defective in patients with hemophilia B. Both are designed to control or prevent spontaneous bleeds driven by the lack of FIX.

While BeneFIX was approved originally as an on-demand treatment to control spontaneous bleeding episodes and manage bleeds during surgery in adults and children, Ixinity initially was approved to be used as an on-demand and surgery management treatment in adults and children 12 and older.

Last year, the FDA approved two supplemental biologic license applications (sBLAs) submitted by Pfizer and Aptevo, which requested an expansion of regulatory approval of BeneFIX and Ixinity to cover routine prophylaxis, or preventive treatment, of bleeds in both adults and children with hemophilia B.

After reviewing its records, the FDA found that the approval of the added pediatric indications for both therapies should not have been granted due to the existence of orphan drug exclusivity rights that were still in effect for another product.

That product was Takeda’s Rixubis, the first recombinant FIX product to be approved in the U.S. as a routine prophylactic treatment for adults and children with hemophilia B, as well as to control and prevent bleeds, and manage those taking place during surgery.

A few years earlier, the FDA named Rixubis an orphan drug, a designation that allows for a medication to retain a seven-year period of market exclusivity for the approved indications.

In rescission letters sent to Pfizer and Aptevo, the FDA explained the market exclusivity rights for Rixubis will remain in effect until September. Until then, the U.S. agency will not be able to approve BeneFIX and Ixinity as routine prophylactic treatments for children with hemophilia B.

However, this rescission will not have any impact on the original indications for which BeneFIX and Ixinity had been approved for previously. In addition, both therapies will be allowed to be used as routine prophylactic treatments for adults with hemophilia B, as approved last year.

The FDA also alerted the companies for the need to review and update the label of both BeneFIX and Ixinity to reflect these alterations.