Affitech AS, the human antibody therapeutics company has successfully completed milestone in its long-term antibody discovery partnership with Peregrine Pharmaceuticals.

At 2008 Annual Meeting of the American Association for Cancer Research (AACR), Peregrine presented preclinical studies demonstrating that PGN635, a fully human antibody discovered as part of their collaboration, exhibits anti tumour efficacy by targeting phosphatidylserine (PS).

Peregrine currently has an anti-PS antibody, bavituximab, that is in phase II clinical trials for the treatment of breast and lung cancers and in a phase I study for the treatment of chronic HCV infection.

PGN635 was isolated using Affitech unique methods for selection and improvement of fully human antibodies from large libraries. In vitro studies demonstrate that by blocking the anti-inflammatory signals of the phosphatidylserine found on the surface of targeted cells, PGN635 could create a unique tumour microenvironment through enhanced production of the pro-inflammatory cytokines TNF-alpha and GM-CSF, while decreasing production of anti-inflammatory cytokines such as interleukin 10. The studies also show that PGN635 promotes the migration of tumour-killing macrophages and induces antibody-dependent cell-mediated cytotoxicity. In addition to the in vitro studies, in vivo studies showed that, the antibody localizes to tumour blood vessels, but not to blood vessels of healthy tissue.

Peregrine will continue to assess the potential of this antibody for the treatment of solid tumours and other diseases. "These excellent results mark another milestone in our collaboration with Peregrine and our ability to discover fully human antibodies with excellent properties. They follow our recent announcement on R84, a fully human anti-VEGF antibody that we have also identified for Peregrine which has performed well in preclinical studies compared to Avastin, comments Martin Welschof, CEO of Affitech.

We are building a strong track record of generating antibodies with superior properties and functionality for our collaboration programs. In addition, we are building up our own oncology pipeline with the help of our innovative CBAS (Cell Based Antibody Selection) discovery system.

Commenting on the milestone achievement Steven King, president and CEO of Peregrine Pharmaceuticals said, "We have been very pleased with the teamwork and productivity of our collaboration with Affitech. Through this collaboration we have been able to generate human antibodies against several targets that we believe may have significant future potential. We look forward to continuing our fruitful collaboration with Affitech".