Today, the FDA announced that it approved Retacrit (epoetin alfa-epbx) as a biosimilar to Epogen® for the treatment of anemia caused by chronic kidney disease, chemotherapy, or use of zidovudine in patients with HIV infection. The FDA also approved Retacrit for use before and after surgery to reduce the chance that red blood cell transfusions will be necessary due to blood loss during surgery. The FDA’s approval was granted to Hospira, which is now a Pfizer company by virtue of Pfizer’s acquisition of Hospira in 2015.
According to the FDA, approval “is based on a review of evidence that included extensive structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamic data, clinical immunogenicity data and other clinical safety and effectiveness data that demonstrates Retacrit is biosimilar to Epogen/Procrit.” The FDA further noted that although Retacrit has been approved as a biosimilar, it has not been approved as interchangeable with Epogen®.
Retacrit is the first epoetin alfa biosimilar to be approved by the FDA, and just the tenth biosimilar approved overall. In announcing the approval, Pfizer stated that “[a]s the first approved epoetin alfa biosimilar in the U.S., RETACRIT may provide patients and their physicians with increased access to a high-quality, lower-cost alternative treatment option for anemia and the reduction of allogeneic red blood cell (RBC) transfusions in certain patients.” Pfizer also stated that “RETACRIT is expected to be available in the U.S. at a significant discount to the current wholesaler acquisition cost (WAC) of Epogen and Procrit.”
The FDA’s approval of Retacrit comes nearly a year after it issued a complete response letter (“CRL”) to Pfizer regarding the then pending application. As we previously reported, Pfizer stated that the CLR did not specifically relate to the manufacture of Retacrit, but was in response to matters noted in a Warning Letter following a routine inspection of a manufacturing facility that was identified as a potential manufacturing site for its epoetin biosimilar.
Hospira and Amgen are currently involved in litigation over patents that Amgen has asserted over this biosimilar. Last September, a jury in the District of Delaware found Hospira liable for infringing one of the two patents at issue and awarded Amgen 70 million dollars in damages. However, post-trial motions filed by both Hospira and Amgen are still pending, and so the judgment is not final. In addition, the patent that Hospira was found to infringe has now expired.