The FDA Approves Its First Biosimilar, Zarxio

The Food and Drug Administration has approved its first biosimilar, Zarxio (filgrastim-sndz), for all five of its counterpart Neupogen's authorized indications.

The Food and Drug Administration has approved its first biosimilar, Zarxio (filgrastim-sndz), for all five of its counterpart Neupogen's authorized indications.

The drug is now approved for patients with cancer who are receiving myelosuppressive chemotherapy, patients with acute myeloid leukemia receiving induction or consolidation chemotherapy, patients with cancer undergoing bone marrow transplantation, patients undergoing autologous peripheral blood progenitor cell collection and therapy, and those with severe chronic neutropenia.

"Biosimilars will provide access to important therapies for patients who need them," FDA Commissioner Margaret A. Hamburg, said in a statement. "Patients and the health care community can be confident that biosimilar products approved by the FDA meet the agency's rigorous safety, efficacy and quality standards."

Filgrastim, a man-made version of granulocyte-colony stimulating factor (G-CSF), was unanimously recommended for approval in early January by the FDA's Oncologic Drugs Advisory Committee (ODAC).

U.S. 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.

Zarxio, which is being developed by Sandoz Biopharmaceuticals, a unit of Novartis, is manufactured using recombinant technology in E. coli host cells. The production process involves various steps that isolate and purify met-C-GSF. The drug is produced in pre-filled syringes and at the same strengths as filgrastim.

"Filgrastim has proven clinical value in treating patients at increased risk of neutropenia, but it is underused in the U.S. for a variety of reasons, including price," Louis Weiner, chairman of the department of oncology and director of the Lombardi Comprehensive Cancer Center at Georgetown University, said in a statement. "Biosimilars have the potential to increase access and the approval of Zarxio may reduce costs to the healthcare system. The comprehensive data set supports its use in clinical practice."

In the study submitted to the FDA, all patients received six cycles of TAC chemotherapy (taxotere, adriamycin and cytoxan) and were randomized to either six cycles of EP2006, six cycles of filgrastim, or one of two six-cycle regimens that rotated between the two drugs.

The primary endpoint was duration of severe neutropenia (DSN), which the researchers defined as the number of consecutive days a patient's ANC was <0.5 Gi/L after the first cycle of chemotherapy. For this analysis, which included 204 patients, the researchers combined all patients who received Zarxio in the first cycle and compared them with all patients who received filgrastim in the first cycle.

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. There were no significant adverse event differences.