Compound Therapeutics Inc. expanded its first financing round, raising $15.5 million to advance its lead cancer product, an AdNectin-based protein antagonist, into trials next year.

The latest round involved the same three venture capital firms - Atlas Venture, of Boston; Flagship Ventures, of Cambridge, Mass.; and Polaris Venture Partners, of Boston - that invested in May 2003. To date, Compound's total equity capital is $28 million.

Frank Lee, president and CEO of the Waltham, Mass.-based company, said the programs and technology Compound acquired during the last year spurred additional fund raising.

"Based on everything the company had done, the investors got involved in the expansion of the Series A round," he said. "It's going to really help us take the company forward."

The first part of the financing round, completed in May 2003, raised about $12 million for development of Adzymes, or addressable enzymes. (See BioWorld Today, May 29, 2003.)

At the time, those funds were estimated to sustain the company for two years, but "about a year ago we completed the acquisition of some intellectual property and a lead discovery platform that's allowed us to really accelerate our lead program," Lee told BioWorld Today.

Compound purchased for $4 million PROfusion, a lead discovery technology that isolates high-affinity binding proteins, along with the protein-antagonist platform AdNectin and an oncology candidate program, from Lexington, Mass.-based Phylos Inc. in December 2003. Compound began using the newly acquired technology in conjunction with its own drug discovery platform, which works with binding proteins linked to Adzymes to find lead drugs. (See BioWorld Today, March 10, 2004.)

"I expect this round of financing, plus other activities in business development, to last us well into mid-2006 and beyond," Lee said, adding that other areas of business development include "alliances and collaborations with other companies."

In September, Compound out-licensed its PROfusion technology to Abbot Laboratories, of Abbott Park, Ill., on a nonexclusive basis, for drug discovery research in human antibody products. Figures were not disclosed, though Compound received an up-front payment and is eligible for milestones and royalties from resulting products.

Lee said a potential "set of alliances will be based on our discovery technologies and discovery capabilities," using the company's two product platforms, AdNectin, which is a non-antibody protein antagonist, and Adzymes, catalytic protein antagonists.

Compound also expects to initiate product-based collaborations to commercialize and market products such as its lead oncology drug, CT-322.

CT-322 is an anti-angiogenic drug designed to restrict tumor growth. Based on the AdNectin platform, CT-322 works by inhibiting the vascular endothelial growth factor receptor-2 (VEGFR-2), Lee said, adding that the drug "modulates angiogenesis and has already shown efficacy in a variety of preclinical models."

He said CT-322 is advantageous to competitive products "because it is a small molecule, its pharmacological properties can be easily modulated, and it can be expressed and manufactured in E. coli."

Because it can be manufactured in E. coli, the company is able to save time and expense in development. The products also will be engineered to attack specific targets more directly than antibody products on the market, he said.

Compound expects to move CT-322 into clinical trials next year, to be funded by the recently raised $15.5 million. The money also goes toward advancing a second oncology product into preclinical development. Lee said the company is in discussions with potential partners for the product.

Last March, when Compound added PROfusion and other intellectual property to its resources, the company had about 20 employees. Since then, the number has doubled.

"We now have a research staff that covers discovery all the way through development," Lee said. "We don't anticipate any more resources going to the discovery area because the technology platform we have now is very efficient and should be adequate to discover lead candidates for our program."

Compound was founded in September 2002.