NEW YORK (AP) ¿ BioSante Pharmaceuticals Inc. said it is adjusting its exchange ratio with Cell Genesys Inc. as the companies prepare to complete their all-stock tie up.

BioSante agreed to acquire Cell Genesys in June in a deal then valued at $38 million. Late Tuesday, the company said Cell Genesys shareholders will get 0.1828 shares of BioSante for every Cell Genesys share held. It raised that rate from 0.1615 shares because Cell Genesys has $23.8 million on hand, or $1.7 million more than expected.

The two companies will hold meetings on Sept. 30 where shareholders will vote on the deal. Pending approval, they said the deal will close shortly after that. If the deal is completed, the company will retain the BioSante name, and current BioSante shareholders will own 62 percent of the combined company.

BioSante of Lincolnshire, Ill., said the combined company would focus primarily on LibiGel, a topical testosterone gel intended to treat sexual dysfunction in women. The company will also look to develop Cell Genesys' cancer treatment GVAX. That may include testing GVAX in combination with BioVant, a BioSante product designed to make vaccines more effective. It could also license Cell Genesys technologies to other companies.

Cell Genesys, based in South San Francisco, Calif., was developing GVAX, an immune treatment for prostate cancer, but discontinued testing last year after one trial was likely to fail and another had an unexpectedly high rate of patient deaths.

In midday trading, BioSante shares were unchanged at $2, and Cell Genesys stock added 3 cents, or 7.5 percent, to 39 cents.

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