We previously reported that after a public meeting held on May 25, 2017, the FDA’s Oncologic Drug Advisory Committee (ODAC) recommended Pfizer’s proposed biosimilar to Amgen’s Epogen®/Procrit® for approval across all indications. The ODAC committee voted 14-1 in favor of approval of Pfizer’s application.

Surprisingly, however, the FDA did not approve the application as expected. Rather, Pfizer announced last week that it had received a second complete response letter (“CRL”) from the FDA for its proposed epoetin alfa biosimilar.

As discussed in our prior post, this application has an unusual history. Hospira submitted the aBLA in December 2014 before it was acquired by Pfizer in 2015. The application was initially rejected by the FDA in October 2015, and afterwards very little was known about the status of the application until the ODAC committee meeting was announced earlier this year.

According to Pfizer’s press release, the most recent rejection “relates to matters noted in a Waring Letter issued on February 14, 2017 following a routine [FDA] inspection of the company’s facility in McPherson Kansas in 2016.” Importantly, Pfizer also stated that “the issues noted in the warning letter do not relate specifically to the manufacture of epoetin alfa.” Additionally, no further clinical data was requested by FDA in the CRL. Pfizer has not provided information regarding the timeframe for its response to FDA.

Amgen and Pfizer/Hospira are currently engaged in litigation over infringement of two patents related to this product. The litigation, which also alleges claims related to the disclosure requirements of the BPCIA, was filed in September 2015. A detailed summary of the litigation is available here as part of RFEM’s Litigation Spotlight series.