Sirna Therapeutics Inc. is raising about $28 million through a private placement to advance its lead product, Sirna-027, through Phase II studies in wet age-related macular degeneration and move preclinical candidates for hepatitis C and dermatology into human trials.

The company did not release the number of shares, though the price has been fixed at $1.60 each. Part of the placement is expected to close this week, with the remainder to close at a later date.

"Next year, in 2006, we will have three programs in clinical trials," said Rebecca Robison, senior director of corporate strategy for the Boulder, Colo.-based company. "So that money is well needed for moving forward the development pipeline," while continuing to build up a preclinical pipeline using Sirna's short-interfering RNA (siRNA) technology.

Those funds are expected to "last beyond just a single year," she added.

Sirna's lead product, Sirna-027, a VEGF inhibitor designed to treat wet age-related macular degeneration, is set to begin Phase II studies during the first half of next year. VEGF has garnered attention lately in the wet AMD space - note the approval of New York-based Eyetech Inc.'s Macugen, a pegylated aptamer, in December, and promising Phase III results recently released for South San Francisco-based Genentech Inc.'s humanized antibody fragment, Lucentis - but Sirna said early results indicate that its own product could be a tough competitor.

A chemically modified siRNA, Sirna-027 aims to use the body's existing molecular mechanisms to halt the growth of blood vessels in the macula. The product targets VEGF receptor-1, and therefore plays into the placental growth factor, believed to be important in treating AMD, Robison said.

The company initiated a Phase I trial in November to evaluate the drug, which was administered in a single intravitreal injection to about 25 patients. Interim results were presented at the 2005 Association for Research in Vision and Ophthalmology meeting in Fort Lauderdale, Fla., in May.

"We released safety data on 14 patients and visual acuity data on 10 patients," Robison told BioWorld Today, adding that results from a few additional patients were released at the Biotechnology Industry Organization conference in Philadelphia last month.

In addition to data showing Sirna-027 to be safe and well tolerated, those early results also demonstrated that all patients experienced stabilization in visual acuity, and 31 percent of those showed significant improvement of greater than three lines, "which is better than either Lucentis or Macugen during their Phase I trials," she said. "We're very encouraged by those results to date."

Sirna's hepatitis C and dermatology programs are set to begin Phase I studies during the second half of 2006. The company advanced several stabilized siRNAs into preclinical testing to treat hepatitis C virus in 2003, and since then, has recorded some promising results regarding the reduction of viral load.

"We have to do an HBV surrogate for small animal models," Robison said, since there is no HCV model for small animals. Those models have demonstrated the ability of the company to overcome a "huge hurdle" to deliver siRNAs systemically in therapeutically relevant doses.

"Right now, we are demonstrating with our current formulations over a 3-log knockdown of the virus at day seven," she added. Sirna plans to take the HBV program, running in primates, and translate it to an HCV program in humans with the start of clinical trials.

Sirna's third program focuses on dermatology, specifically the "hairless program," Robison said, "where we're knocking down the hairless transcription factor."

The company's pipeline also includes an oncology program partnered with Indianapolis-based Eli Lilly and Co. The agreement calls for Sirna to use its RNAi technology against Lilly's targets for cancer indications.

A program aimed at developing therapies for Huntington's disease is partnered with Targeted Genetics Corp., of Seattle. Sirna also has ongoing preclinical programs in asthma and diabetes.

The company ended the first quarter with a net loss of $8 million, or 19 cents per share. As of March 31, the company has cash, cash equivalents and marketable securities totaling $24.9 million.

Sirna recently appointed J. Michael French senior vice president for corporate development. French will lead activities such as partnerships, collaborations, product licensing, and mergers and acquisitions.

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