BioWorld International Correspondent

PARIS - Serono SA reported positive preliminary results from a multicenter trial evaluating the long-term safety and tolerability of continuous administration of Raptiva (efalizumab) for moderate to severe psoriasis.

The study, in which 64 percent of the 228 patients treated for the full 15 months showed 75 percent or better improvement in their condition (and 79 percent showed a 50 percent improvement), confirms the outcome of three earlier Phase III trials of Raptiva. The drug was administered by subcutaneous injection once a week.

Earlier this month Serono submitted a marketing authorization application for Raptiva to the European Medicines Evaluation Agency in London for the adult treatment of moderate to severe psoriasis, and is due to file the drug in Canada, Australia and Switzerland very shortly.

Serono is developing and marketing Raptiva under an exclusive license agreement signed with Genentech Inc. in August. The companies signed a second agreement in February expanding the geographical scope of the license to include an additional 15 Asian countries, which means Serono now has rights to develop and commercialize the drug for all markets outside the United States and Japan. Developing and marketing rights in the U.S. remain with Genentech and its American partner, XOMA Ltd., and in December the companies filed a biologics license application for Raptiva with the FDA.

Raptiva is a recombinant humanized monoclonal antibody designed to inhibit the adhesion of T lymphocytes to other cell types by inhibiting the binding of LFA-1 to ICAM-1. As a targeted T-cell modulator, it is designed to block the activation of the T cells that cause psoriasis, without destroying them. The drug also is in Phase II trials for rheumatoid arthritis and is being evaluated for psoriatic arthritis.