OrbiMed Advisors, which invested in SGX Pharmaceuticals Inc. in 2000, has placed a new bet on the now-public cancer-drug maker.

OrbiMed and Great Point Partners have participated in a $25 million private placement for SGX, which raised $105 million from OrbiMed, BA Venture Partners (now Scale Venture Partners), Atlas Venture, Apple Tree Partners, Sprout Group and others before going public in February 2006, according to VentureOne, a research unit of Dow Jones & Co., publisher of VentureWire.

SGX is much different today from what it was when OrbiMed made its initial investment, taking part in a $45 million third round in September 2000. Then, it was a platform company known as Structural GenomiX Inc. that was establishing a structural biology-based drug-discovery platform.

Today, the San Diego company -- which changed its name to SGX in 2005 -- is advancing a pipeline of drug candidates discovered through that technology platform. Its most mature product, a solid-tumor cancer therapy, will enter clinical trials in early 2008.

This financing should enable SGX to put a total of three cancer therapies into clinical trials by mid-2009, according to Chief Executive Mike Grey. SGX is issuing 4.9 million shares of common stock at $5.05, plus seven-year warrants to purchase up to 1.4 million shares of common stock at an exercise price of $5.77. SGX closed at $5.05 yesterday, up 0.6% from Monday's closing price of $5.02.

OrbiMed officials were not available for comment, and it was not immediately clear if the firm still holds shares from its original investment. SGX's two largest shareholders are BA Venture Partners and Atlas Venture, which each holds just over 16% of the company, according to its most recent proxy statement. Sprout owns 9.2% of the common stock, and Index Ventures holds 5.5%, according to the regulatory filing.

With multiple drugs expected to enter clinical testing, SGX's stock price could be poised for an upswing. JMP Securities analyst Charles Duncan has a "market outperform" rating on the company and 52-week price target of $8. If its products show promise in the clinic, SGX could be an attractive target for corporate acquirers within the next two years, he said.