FDA approves Rebif. (News).

This March, the U.S. Food and Drug Administration (FDA) approved Rebif, a form of interferon beta-1a manufactured by Serono, for treatment of relapsing forms of MS. With the addition of Rebif, there are now five drugs--Avonex, Betaseron, Copaxone, Novantrone, and Rebif--approved in the United States for modifying the course of major forms of MS. Avonex, Betaseron, Copaxone, and Rebif are approved for relapsing forms of MS; Novantrone is approved for progressive as well as rapidly worsening relapsing forms of MS.

The FDA approval was based on results from two clinical trials: the PRISMS study and the EVIDENCE study. (See story on page 45.) Since the results from the PRISMS trial were first announced in 1997, Rebif has been prescribed for MS in over 60 countries worldwide. Rebif is taken by subcutaneous (under the skin) injection three times a week.

Avonex, which is also interferon beta-la, was given a seven-year exclusive U.S. market under the provisions of the Orphan Drug Act. This law provides incentives for pharmaceutical companies to research and develop medications for conditions that affect a limited number of people. Rebif was initially not to be available in the United States until mid-2003, unless clinical superiority of Rebif over Avonex could be demonstrated.

To gain earlier approval in the U.S., Serono sponsored a direct "head-to-head" comparison of Rebif and Avonex in the EVIDENCE trial. In approving Rebif prior to mid-2003, the FDA signaled its view that Rebif showed superiority over Avonex within the confines of the EVIDENCE trial.

Side effects for both Rebif and Avonex--including flu-like symptoms--were in line with what had been reported previously for interferon betas. According to Serano, the approximate price of Rebif is $13,875 annually.

Each of the approved treatments has pros and cons. The choice of therapy for any particular individual should be made in consultation with his or her personal physician.