After years of debate and regulatory hurdles, a milestone was achieved today when the FDA approved the first biosimilar in the United States.

Filgrastim-sndz (Zarxio) manufactured by Sandoz, Inc, is biosimilar to Amgen Inc’s Neupogen (filgrastim), which was originally approved in 1991.

Zarxio was approved for the same indications as Neupogen, for the treatment of patients receiving myelosuppressive chemotherapy; those with acute myeloid leukemia receiving induction or consolidation chemotherapy; patients undergoing bone marrow transplantation; those undergoing autologous peripheral blood progenitor cell collection and therapy; and those with severe chronic neutropenia, the FDA said.

“Biosimilars will provide access to important therapies for patients who need them,” FDA Commissioner Margaret A. Hamburg, MD, said in a press release. “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.”

Zarxio was approved following an evaluation of the structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamics data, clinical immunogenicity data, and other data that showed it is biosimilar to Neupogen. The drug is not an interchangeable product, however. A biological product approved as interchangeable may be substituted for the reference product without health care provider intervention.

On July 24, 2014, Sandoz, a Novartis company, became the first firm to file for approval of a biosimilar in the United States through the pathway created by the Biologics Price Competition and Innovation Act of 2009. On January 7, 2015, the FDA Oncologic Drugs Advisory Committee recommended approval of the biosimilar for filgrastim.

Common side effects of Zarxio include bones or muscles aches and redness, and swelling or itching at injection site. Serious side effects can include spleen rupture; serious allergic reactions that may cause rash, shortness of breath, wheezing and/or swelling around the mouth and eyes; ekevated pulse and sweating; and acute respiratory distress syndrome, according to the FDA.

"The FDA approval of Zarxio marks a significant milestone for the United States healthcare system and for patients who might suffer from neutropenia," Carol Lynch, global head of Biopharmaceuticals and Oncology Injectables at Sandoz, said in a press release. "As the global leader in biosimilars, we are honored to be the first company to successfully work with FDA to navigate the US biosimilar pathway and we look forward to making this high-quality biosimilar available to patients in the US."

The name filgrastim-sndz was designated by the FDA as a placeholder nonproprietary name for the product. The nonproprietary name for the product is not to be viewed as a reflection of the FDA decision on a comprehensive naming policy for biosimilar and other biological products, the agency noted in a press release. 

In an interview last year with Specialty Pharmacy Times, Javier Coindreau, MD, vice president of global medical affairs for Pfizer Biosimilars Business Unit, noted the importance of biosimilars being introduced to the US market for lowering the cost burden on patients.

“One of the things biosimilars provide is competition, and with that the potential for increased access,” he said. “One of the most important reasons biosimilars should be available is the need for these drugs are huge and in most cases, in these therapeutic areas, access is not easy. So by increasing competition, biosimilars increase access for patients requiring these drugs but who currently don’t have access.”