Sandoz’s Zarxio Becomes First Biosimilar in U.S. History

The FDA last Friday gave a green light to the first U.S. biosimilar, finding Sandoz’s Zarxio clinically comparable to Amgen’s blockbuster chemotherapy product Neupogen.

Approval came exactly 10 months after the FDA accepted Sandoz’s application — the first under the 2010 biosimilars pathway — and is in line with the agency goal to respond to 80 percent of biosimilar applications within 10 months. The therapy was approved as biosimilar, rather than the higher designation of interchangeable, which Sandoz didn’t seek. Unlike biosimilars, interchangeables can be directly substituted by the pharmacist without a new prescription.

Approved under the brand name Zarxio (filgrastim-sndz), the biosimilar was granted all five indications of Neupogen. Approval had been widely anticipated after an FDA advisory committee unanimously recommended the agency sign off on the product in January, largely based on millions of days of exposure the biosimilar has seen in patients across Europe, where it is marketed under the name Zarzio.

With Zarxio’s approval, there remain four publicly disclosed biosimilar applications pending with the FDA.

Perhaps the most closely watched aspect of the FDA’s approval is the international nonproprietary name, or INN, granted the biosimilar. Rather than allowing Sandoz’s version to simply take Neupogen’s (filgrastim) INN, the FDA assigned the biosimilar a four-letter qualifier. That appears to be in line with the naming convention proposed by the World Health Organization and endorsed by BIO last summer, possibly foreshadowing the approach the FDA will take in its official biosimilars naming policy.

The FDA declined to say when the naming guidance will be published, noting only that it is due sometime this year. The agency cautioned that the Zarxio qualifier is merely a placeholder and shouldn’t be seen as reflecting the agency’s decision on a comprehensive naming policy.

While Sandoz is now free to market the therapy, the placeholder INN could theoretically be changed after the guidance comes out, said John Jenkins, CDER’s director of new drugs.

Sandoz is among companies that have argued for biosimilar names to be treated the same as generics, which are indistinguishable from their reference product.

The brand name, rather than a unique INN qualifier, is the most effective way to identify pharmaceutical products, Sandoz parent company Novartis said. The firm notes there have been no issues with traceability for other standalone biologic products with the same INN approved in the U.S.

The FDA’s sign-off doesn’t ensure smooth sailing for Zarxio. Amgen continues to challenge Sandoz’s bid in court, with a hearing on a preliminary injunction sought by the brandmaker scheduled for March 13.

Sandoz has promised not to market Zarxio until either April 10 or a ruling in its favor in that lawsuit, whichever comes first.

According to an SEC filing, Amgen had $839 million in U.S. sales last year from Neupogen, plus another $320 million outside the U.S. — Bryan Koenig