BioWorld International Correspondent

PARIS - Serono SA now owns 91.8 percent of the equity and voting rights of Genset SA, following the extension of the offering period for its takeover bid from Sept. 12 to Oct. 31.

The French Financial Markets Council said on Friday that the French subsidiary of the Geneva-based biotechnology company, Serono France Holding SA, held 7,557,702 Genset shares, out of a total of 8,232,350, as well as 515,931 convertible bonds (98.8 percent of the 522,223 bonds outstanding), and all outstanding Genset warrants.

Serono France added that it would continue to purchase Genset shares on the Nouveau Marché in Paris at €9.75 per share and would inform the market when it stopped buying them.

Meanwhile, Serono signed a worldwide drug development agreement with IVAX Corp., of Miami, for the development and commercialization of the U.S. company's cladribine as potentially the first effective oral treatment for multiple sclerosis.

Cladribine is a purine analogue that disrupts the proliferation of certain white blood cells, such as monocytes and lymphocytes, that are involved in the pathological process of MS. Using clinical and magnetic resonance imaging data from Phase II trials that showed intravenous cladribine could be effective in treating some MS patients, Serono and IVAX plan to optimize an oral formulation of the drug and test it in further trials.

The agreement provides for IVAX to receive a series of unspecified milestone payments from Serono, as well as royalties on sales of the product once it reaches the market.

Serono CEO Ernesto Bertarelli described the deal as "part of our long-term strategy for developing novel therapies in neurology. With cladribine, we plan to offer patients an oral therapy which complements Rebif, our leading treatment for multiple sclerosis."