Peregrine Pharmaceuticals announced the issuance of US Patent No. 6,696,276 that covers its Vasopermeation Enhancement Agent (VEA) technology. The patent, titled “Vasopermeability-Enhancing Conjugates,” further expands Peregrine’s patent coverage for general concepts of using agents that localize to tumours and induce tumour blood vessels to become more permeable in order to make chemotherapy drugs and diagnostic agents more effective.

Vasopermeation Enhancement Agents are sensitizing agents that enhance the effectiveness of cancer therapy or diagnosis by allowing a greater amount of an administered drug or diagnostic agent to reach the target tumour cells. VEAs are pre-treatments that use a targeting agent, such as a monoclonal antibody, to deliver an effector that works to make tumour blood vessels more leaky. As a result, chemotherapy and tumour cell targeted therapeutics are better able to move beyond the tumour blood vessels and reach the tumour cells, resulting in improved anti-tumour effects. The Company has successfully used its proprietary Tumour Necrosis Therapy (TNT) technology as the targeting agent and the cytokine interleukin 2 (IL-2), or fragments and mutants of IL-2, as the basis of its VEA technology platform.

In published reports, VEA pre-treatment increased by almost 400 per cent the normal amount of chemotherapeutic agent taken up by solid tumours. In pre-clinical studies, Peregrine’s VEA technology has been shown to significantly improve the effectiveness of chemotherapeutic agents including Doxorubicin, Taxol, Vinblastine, VP-16 and Taxotere in tumour therapy experiments. Peregrine’s VEAs utilize its human TNT targeting platform to make it possible to use a single VEA as a pre-treatment for a variety of different tumour types and chemotherapeutic agents. Data related to the VEA technology platform has been published in a number of peer reviewed journals including, most recently, the Journal of the National Cancer Institute, and the technology has been reviewed in Lancet Oncology and Nature Reviews Cancer.