PARIS - The results of a Phase I clinical trial of a vaccine against prostate cancer, developed by the Strasbourg-based gene therapy company Transghne, indicate a good level of tolerance and some antitumor activity.

The VV-MUC1-IL2 therapy, which entails the use of a vaccinia virus vector for delivering Muc1 tumor antigens and the cytokine interleukin-2 that stimulates an immune system response, is undergoing trials at the University of California in Los Angeles.

The product is based on the fact that the Muc1 antigen is present in patients suffering from prostate, breast and lung cancers, as well as several other types of cancer, and is designed to trigger a reaction by the patient's immune system against cancer cells expressing the Muc1 antigen. In this trial, it was administered by intramuscular injection to prostate cancer sufferers who already had been given other treatments but whose cancer was showing signs of progression.

As well as being well tolerated by all the subjects, the therapy triggered an antitumor response in one patient that lasted for more than one year and resulted in the stabilization of the cancer in two other patients. These results confirm those obtained last year in a Phase II trial of the same therapy for the treatment of metastatic breast cancer. Transghne's head of medical and regulatory affairs, Michael Ross, welcomed these latest results, saying they "vindicate the company's investment in the development of the Muc1 vaccine for the treatment of both breast cancer and prostate cancer."

The VV-MUC1-IL2 anticancer vaccine is one of two antigen-specific immunotherapies for cancer developed by Transghne. The other, which uses a vaccinia virus vector derived from the MVA strain to deliver genes carrying the human papilloma virus antigen HPV-16 that is responsible for over half of all cervical cancers, also is in clinical trials.