A Food and Drug Administration (FDA) advisory committee unanimously recommended approval of a biosimilar version of Neupogen (filgrastim). If the FDA follows the recommendation, the drug, EP2006, would become the first biosimilar approved in the United States.
Filgrastim is a man-made version of granulocyte-colony stimulating factor (G-CSF), a protein that stimulates production of neutrophils. When injected into the body, filgrastim has the same effect as G-CSF, increasing an individual’s ability to fight infections.
Filgrastim is approved for chemotherapy-induced febrile neutropenia in patients with nonmyeloid malignancies, for patients with acute myeloid leukemia receiving induction or consolidation chemotherapy, and for patients receiving bone marrow transplants to treat their cancer. The drug also has approved indications to treat patients with severe chronic neutropenia and patients undergoing peripheral blood progenitor cell collection and therapy.
US law defines biosimilars as biological products demonstrated to be “interchangeable” with an FDA-licensed biological product. As part of the Affordable Care Act, an expedited approval pathway was established for biosimilars that requires less product-specific data than the FDA’s traditional regulatory channels, allowing reliance on existing efficacy and safety data for the reference product.
By voting in favor of approving EP2006, the Oncologic Drugs Advisory Committee (ODAC) asserted that the drug met the criteria established under this biosimilar pathway. Specifically, the committee is stating that EP2006 is “highly similar” to Neupogen, “notwithstanding minor differences in clinically inactive components,” and that “there are no clinically meaningful differences between EP2006 and filgrastim in terms of [purity], safety, and effectiveness.”
“We have a lot of clinical data that these are very similar compounds and pharmacokinetics and pharmacodynamics are very comparable,” says Deborah K. Armstrong, chairperson of the ODAC meeting and professor of Oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins.
Among all the data considered for the recommendation, the key clinical study ODAC reviewed was the pivotal double-blind phase 3 PIONEER trial (EP06-302), which compared the efficacy and safety of EP2006 and US-licensed Neupogen in patients with breast cancer treated with myelosuppressive chemotherapy.
The results showed that the study met its primary endpoint. The data also showed that repeated switching at each cycle between the investigational biosimilar and Neupogen had no impact on efficacy, safety or immunogenicity.
In explaining her “yes” vote, Ginna G. Laport, clinical research director in the Division of Blood & Marrow Transplantation at Stanford University Medical Center, said the data supplied by the manufacturing company, Sandoz, was convincing. “What really moved me was the very strong evidence shown by the sponsor for biosimilarity in numerous studies.”
Sandoz already manufactures a biosimilar version of filgrastim under the brand name Zarzio in more than 40 countries. According to Sandoz, Zarzio is the leading daily G-GSF used daily in Europe.