Zarxio becomes first approved biosimilar in US
The FDA approved filgrastim-sndz, making it the first biosimilar product to receive regulatory approval in the United States.
Filgrastim-sndz (Zarxio, Sandoz) is used primarily to decrease the incidence of infection — manifested by febrile neutropenia — in patients with nonmyeloid malignancies who also receive myelosuppressive anticancer drugs.
Filgrastim-sndz — first approved for use in Europe in 2009 and now available in 60 countries worldwide — is approved for the same five indications as its reference product, filgrastim (Neupogen, Amgen).
Those indications are:
Margaret A. Hamburg
Filgrastim is a biologic agent, an increasingly popular classification of novel drugs that are more complex than chemical drugs. They are typically more expensive than chemical drugs because they can control the market and do not face competition from generic drugs.
To receive regulatory approval, biosimilars — which also are biological products — must be shown to be highly similar to an already-approved biological product. The biosimilar must demonstrate it has no clinically meaningful differences in terms of safety and effectiveness from the reference product. Only minor differences in clinically inactive components are allowable in biosimilars.
The FDA was not permitted to consider approval of biosimilars until the passage of the 2010 Patient Protection and Affordable Care Act.
Although biosimilars are not generics because living organisms cannot be copied absolutely, they are nearly identical to the biologic originators. Generics often gain approval without clinical trials, but biosimilars will require some time in trials.
Approval of alternatives to the biologics would cause competition in the marketplace and, as such, could keep costs down.
“Biosimilars will provide access to important therapies for patients who need them,” Margaret A. Hamburg, MD, commissioner of the FDA, 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.”
In January, the FDA’s Oncologic Drugs Advisory Committee unanimously recommended the approval of filgrastim-sndz.
The advisory committee based its recommendation primarily on data presented by Sandoz, a subsidiary of Novartis.
Those data included the results of the PIONEER study, a phase 3 randomized double blind trial in which the efficacy and safety of the biosimilar were compared with the original version of filgrastim in patients with breast cancer.
In that trial, 218 patients from 27 centers received either filgrastim-sndz or its reference product. Results indicated the efficacy and safety of the biosimilar was comparable to that of the reference product for the prevention of neutropenia, and that repeated switching between the two agents had no impact on outcomes.
The FDA also reviewed evidence that included comparative structural and functional characterization, animal studies, and pharmacokinetic, pharmacodynamic and clinical immunogenicity data.
The most common adverse effects associated with filgrastim-sndz include aching in the bones or muscles, as well as redness, swelling or itching at the injection site.
Serious adverse effects may include spleen rupture; serious allergic reactions that may cause rash, shortness of breath, wheezing and/or swelling around the mouth and eyes; fast pulse and sweating; and acute respiratory distress syndrome.
The recommended dose and schedule of filgrastim-sndz is the same as for its reference product.