To further develop its tissue factor pathway inhibitor (TFPI) program, EntreMed Inc. tapped Affymax Inc. as a collaborative partner.

The companies entered a research collaboration for the synthesis and development of peptides that mimic certain fragments of TFPI, a naturally occurring anticoagulant protein that in preclinical models has been shown to inhibit tumor growth and the formation of new blood vessels. Terms call for EntreMed and Affymax to combine their capabilities in peptide design and drug development to identify lead candidates for cancer.

"TFPI has been an interest of ours for some time, and the goal of getting a candidate into the clinic requires somebody who is familiar with peptide synthesis and that's really where Affymax's strengths lie," Carolyn Sidor, EntreMed's vice president and chief medical officer, told BioWorld Today. "We felt quite comfortable partnering with them in this effort because it allows us to move the program forward at a much greater pace than we could do if we were on our own."

Given its drug development capacity, Affymax's role is directed at peptide synthesis. The Palo Alto, Calif.-based company's approach to peptide architecture and delivery imparts drug-like characteristics to peptides while preserving their specificity and potency. It uses a technology platform called Recombinant Peptide Diversity to create a number of peptides optimized as potential drug candidates.

"We're always looking for new, promising opportunities to leverage our peptide technology to design specific, desired product characteristics that address unmet clinical needs in cancer and hematology," Mary Fermi, Affymax's senior director of commercial development, told BioWorld Today. "This project is a very nice fit with our respective drug development capabilities."

For Rockville, Md.-based EntreMed, its primary focus will center on screening any Affymax-generated peptides for optimal activity. Both parties will share financial responsibilities as the program advances, Sidor said, adding that both also would share monetary benefits from resulting products. More specific financial terms were not disclosed.

As part of the foundation for the deal, EntreMed scientists some time ago identified a peptide fragment of TFPI that maintains the protein's anti-angiogenic and antitumor properties without adversely affecting normal blood clotting when tested in animal models, overcoming past limitations that have prevented the development of TFPI as a therapeutic agent for oncology. Those findings, which stem from a prior collaboration with the American Red Cross, were published in Blood.

"Our collaboration with EntreMed aims to develop a more potent anti-angiogenic compound that does not have the deleterious effect of altering normal blood clotting," Fermi said.

And that previous research represents the tip of the iceberg, so to speak.

"That's where Affymax's expertise comes into play," Sidor said. "They're experts at taking a specific receptor or target and modeling peptides that effectively bind and activate that target. Although we do have a fragment that we've identified that will help us get started in this regard, we expect that they will be able to come up with additional molecules that can be tested that will behave in a better fashion and are more active."

While the deal allows the program to advance with an attractive partner, it also allows EntreMed to focus on getting Panzem NCD (2-methoxyestradiol) into clinical studies early next year. A reformulated liquid version of its lead drug candidate, Panzem capsules, the small molecule is being developed for oncology indications.

The company's other investigational products include analogues of 2ME2, which stem from a program on track to produce an investigational new drug application by the end of this year for oncology and other diseases, and earlier-stage research on proteinase-activated receptor-2 for oncology and inflammatory diseases, such as rheumatoid arthritis.

Affymax's peptide-based pipeline already includes one clinical product, Hematide, a peptide-based erythropoiesis-stimulating agent being developed for anemia associated with chronic kidney disease, cancer and other diseases. The company also is advancing a preclinical peptide that is an agonist of the granulocyte-colony stimulating factor receptor for neutropenia. Other collaborative programs remain undisclosed.

On Tuesday, EntreMed's shares (NASDAQ:ENMD) gained 2 cents to close at $2.01.