Just a month after FDA staff and an advisory committee gave a ringing endorsement to Pfizer's biosimilar for Amgen's blockbuster Epogen, the agency has rejected the drug for the second time.

This time around, an FDA complete response letter (CRL) cited concerns about the same Pfizer fill-finish plant whose problems led the FDA to deny approval of a highly anticipated copy of Teva’s Copaxone that was to be finished there.

Pfizer late Thursday announced (PDF) the FDA had issued the CRL for its proposed epoetin alfa biosimilar, a drug that has been on the market in Europe for a decade. It said the CRL relates to matters noted in a warning letter in February for the company’s facility in McPherson, Kansas.



The drugmaker pointed out that the FDA did not ask for additional clinical data to support a further approval. The FDA had asked for more data when it rejected the same drug in 2015.

RELATED: Pfizer plant slapped with FDA warning letter for not learning from earlier mistakes



Just last month, FDA staff found the Pfizer product nearly identical to the Amgen drug, a product that last year generated nearly $1.3 billion for the California-based biotech. That was followed by an advisory committee review which recommended approval in a 14-1 vote.

RELATED: Pfizer's Epogen biosim scores solid backing from FDA staff ahead of panel review

But the agency couldn’t approve it given that the potential manufacturing site in the BLA for the biosimilar was the same Hospira unit plant which was responsible for an FDA rejection of Glatopa, the highly anticipated long-lasting generic version of Teva’s Copaxone. Developed jointly by Momenta and Novartis, the companies have been told approval, which may not happen for some time now, is dependent upon Pfizer resolving issues at the Hospira fill-finish plant. Pfizer was handling fill-finish on a contract basis for Momenta and Novartis' Sandoz unit.

RELATED: Teva catches break as warning letter looks to delay Momenta Copaxone generic

The problems at the plant were laid out in a scathing warning letter that chastised Pfizer for repeated failings throughout the Hospira manufacturing network. It said Pfizer should have recognized long ago there were issues that needed addressing because the agency had cited five other Hospira plants for similar problems in four warning letters issued in 2010, 2013, 2014 and 2015. Pfizer bought Hospira in 2015 in a $15 billion deal.