Stressgen Biotechnologies Corporation announced a ruling from the European Patent Office, Opposition Division (OD) related to European Patent 0419569B1 filed by the Whitehead Institute. This patent represented the earliest filings from Whitehead covering the use of stress proteins to prepare vaccines for treatment of disease and is exclusively licensed by Stressgen to complement its core intellectual property filings on stress protein fusion technology.

The OD ruled to revoke the patent. This ruling has no impact on Stressgen's core intellectual property filings on stress protein fusion technology and specific fusions such as HspE7, as well as other applications of stress proteins. Additional applications filed by Whitehead covering the use of stress proteins are pending and have also been exclusively licensed by Stressgen, adding to the company's existing intellectual property filings.

"The ruling does not prevent Stressgen from commercialising or further expanding its intellectual property position around the core stress protein fusion technology, now in clinical trials. This patent opposition is a clear indication that stress proteins are increasingly becoming recognized as important commodities in the development of novel immunotherapeutics," said

Daniel L. Korpolinski, president and CEO of Stressgen. "Stressgen has a solid intellectual property position and exclusive rights to commercialise its stress protein fusion technology and specific products, such as HspE7. The Company continues to build upon and around its intellectual property applications."

Stress proteins, also known as heat shock proteins (Hsps), are powerful natural stimulants of the immune system and have many critical biological functions. They offer a number of opportunities for the discovery and development of novel therapeutics. Recent studies have demonstrated that they potently activate the immune cells required to combat virally induced infections and cancers. There is also evidence that they play a key role in the presentation of disease-specific markers, called antigens, to the immune system. These critical immune-stimulating activities, as well as their fundamental roles in several vital cellular functions, make stress proteins valuable tools for therapeutic development.

Stressgen is currently conducting clinical trials for HspE7 in the treatment of sexually transmitted diseases caused by the Human Papillomavirus (HPV). The company has a Phase III trial for HPV-related anal dysplasia, and active Phase II trials in cervical cancer and cervical dysplasia. Stressgen also plans to initiate a Phase II trial in genital warts.

HspE7 is based on Stressgen's proprietary Hsp fusion technology. HspE7, a recombinant fusion product, is composed of heat shock protein 65 (Hsp65) from Mycobacterium-bovis BCG and the protein E7. As a member of the family of stress proteins, Hsp65 is known to elicit a powerful immune response. The E7 protein is derived from the HPV and is involved in the malignant transformation of epithelial cells. E7 is a tumor-specific antigen and represents a precise target for the immune system attack on abnormal cells.