Washington Editor

In its largest financing yet, antiviral firm Chimerix Inc. raised $11 million in its third round.

The San Diego company plans to use the proceeds through 2006 to advance to the clinic its lead antiviral agent for smallpox, CMX001, and broaden the application of its technology to new therapeutic indications.

"The company is multidimensional, and there is more than one iron in the fire," Chimerix President and CEO George Painter told BioWorld Today. "We have our biodefense initiative moving forward, and are planning to begin clinical trials hopefully in the first quarter of '05. We've generated an enormous amount of data, and have had extensive interaction with the FDA, and in that process generated a lot of data that helped to support and broaden the application base of the technology."

Chimerix's technology conjugates a dietary lipid to a drug in order to enhance cell permeability and improve efficacy. As a result, it is designed to enhance oral availability, stabilize a drug in plasma and facilitate delivery into targeted tissues.

"We've gathered enough data that we understand how the compounds are picked up in the gut, how they're distributed, and how the chemistry of the conjugated lipid changes their distribution," Painter said. "We've also begun to get an understanding of how the lipids are metabolized, which helps us better understand when and how much to dose."

The technology comes from the University of California at San Diego, which is why the company maintains its research operations on the West Coast. Development operations are housed in Research Triangle Park, N.C.

The most notable product to stem from the technology to date is CMX001, whose further development will be supplemented by the latest funding. The smallpox program already is bolstered by a $36.1 million grant from the National Institutes of Health in Bethesda, Md. Awarded a little more than year ago, the grant is payable over four and a half years. (See BioWorld Today, Sept. 11, 2003.)

CMX001 derives from cidofovir, marketed in the U.S. as Vistide by Gilead Sciences Inc., of Foster City, Calif. Chimerix developed the product by applying its technology to the intravenously administered AIDS drug to create an orally available option. It was chosen for further development over another compound, CMX-002, as CMX001 proved safer in toxicology studies.

Painter said the company is about to file an investigational new drug application for CMX001 to test its safety in humans. Animal efficacy studies in mice pointed to the product's potential, protecting the animals from death by 100 percent. He noted that the infection's pathogenesis in mice, via the respiratory tract, is similar to what happens in humans. Future animal efficacy studies likely will evaluate CMX001 in nonhuman primates, but that model remains in development.

Privately held Chimerix, which was founded in July 2002, also plans to apply its latest funds to accelerate programs for treating drug-resistant HIV, cytomegalovirus infection, viral hepatitis and other discovery-stage preclinical programs.

A $600,000 Small Business Innovation Research grant has been used to advance the HIV program, and by the middle of next year the company expects to have selected a lead candidate for a 2006 IND. Chimerix has discovered several compounds with activity against cytomegalovirus, and also plans to evaluate CMX001 in that indication. Painter said the company would move that program to an IND stage by the end of next year, and is looking to eventually partner with hepatitis C companies that could use its technology to better target the liver.

To date, Chimerix has raised $16.1 million. A new backer, Frazier Healthcare Ventures in Seattle, led the latest private placement. Two founding investors also bought preferred stock - Sanderling Ventures in San Mateo, Calif., and Asset Management Co. in Palo Alto, Calif.

In conjunction with Frazier's investment, one of its general partners, Robert Overell, joined Chimerix's board.