The US Food and Drug Administration's (FDA) Oncologic Drugs Advisory Committee (ODAC) on Thursday voted 14-to-1 in support of approving Pfizer subsidiary Hospira's proposed biosimilar to Amgen's anemia drug Epogen (epoetin alfa) for all four of its indications.
While Hopsira's epoetin alfa biosimilar has been approved in Europe since 2007, FDA rejected the company's first attempt at US approval in October 2015, just after Pfizer completed its acquisition of Hospira. At the time, Pfizer said it had additional evidence it could use to support the application and signaled its intent to refile.
Epogen was first approved by FDA in 1989, and it is currently licensed to treat anemia in patients with chronic kidney disease, human immunodeficiency virus (HIV) and certain cancers, as well as to reduce the need for red blood cell transfusions as a result of loss of blood from surgery.
If approved, epoetin alfa would be Pfizer's second US biosimilar, after the company received approval for its copy of Janssen's Remicade (infliximab) in April 2016. That biosimilar, known as Inflectra (infliximab-dyyb), hit the market in late 2016. Another Remicade biosimilar was approved by FDA last month.
In a briefing document released ahead of the committee meeting, FDA reviewers said the biosimilar was "highly similar" to the reference product and that there were "no clinically meaningful differences in efficacy and safety" between the two products.
The advisory committee members largely agreed, breezing through questions about the analytical comparability of the two products and whether there were any clinically meaningful differences.
However, some panelists expressed concerns about whether the data presented by Pfizer, especially surrounding immunogenicity, could be extrapolated to support approval for all four of epoetin's indications.
That said, only one panelist, Dr. Thomas Uldrick, clinical director of the HIV & AIDS Malignancy Branch at the National Cancer Institute, voted against approving the biosimilar, though he noted that he "strongly" supports approval for two of the four indications.
"I have residual concerns about lack of immunogenicity and basic safety data in patients with HIV and cancer, and for that reason I voted 'no' for the broader indication," Uldrick said.
Other panelists agreed there is some residual uncertainty related to immunogenicity and extrapolation to all indications, but said that a clearer picture will emerge as a result of postmarket surveillance.
"I think that's when we'll get the clearest picture of whether there really is any uncertainty in how these drugs perform," Scott Waldman, chair of the department of pharmacology and experimental therapeutics at Philadelphia-based Thomas Jefferson University, said.