Berlex Laboratories on Friday filed suit against the FDA in the U.S. District Court for the District of Columbia, to prevent the agency from granting marketing approval for Biogen Inc.'s Avonex beta interferon for multiple sclerosis. According to the complaint, Berlex is seeking a temporary restraining order, preliminary and permanent injunctions and a declaratory judgment to prevent the FDA from granting a PLA and ELA for Avonex.

According to the complaint, Berlex (Wayne, N.J.) claims that if the FDA approves Avonex, it will "unlawfully deprive Berlex of its statutorily-mandated right to the exclusive marketing of its recombinant interferon beta, Betaseron, for treatment of multiple sclerosis (MS). Moreover, approval of Biogen's product would violate the Public Health Service Act (PHS Act) and the agency's own regulations for the approval of biological products."

Biogen's response

BGEN issued a statement saying it considers the suit to be without merit and doesn't expect that Berlex's action will impede its marketing of Avonex. BGEN said that Avonex and Berlex's Betaseron beta interferon are different products, based on their different clinical and safety profiles, molecular structures, methods of manufacturing, dosing regimens and routes of administration. The Cambridge, Mass., company declined further comment.

Betaseron, which is manufactured by Chiron Corp. (Emeryville, Calif.) was approved on July 23, 1993. CHIR isn't a party to the suit. An FDA panel recommended approval of Avonex on Dec. 4, 1995.

Based on a reading of the complaint, as well as the relevant Orphan Drug and biologics regulations, Berlex appears to be following a two-pronged strategy in questioning the FDA's approval process for Avonex.

In a nutshell, the company's arguments are as follows: First, Avonex and Betaseron are sufficiently similar that the Orphan Drug regulations preclude approval of Avonex for the same indication. Second, the compound actually tested in BGEN's clinical trials and reviewed by the FDA and its advisory panel is a different product than the drug that will be marketed as Avonex. Thus, to establish the safety and efficacy of Avonex, additional trials would be required.