Pharmexa vaccine is designed to induce antibody responses against the HER-2 protein

Pharmexa presents data from the HER-2 Protein AutoVac™ breast cancer trial at a Conference in Hamburg Summary: Pharmexa is presenting data from the first clinical trial in USA with the HER-2 Protein AutoVac™ vaccine at the 4th European Breast Cancer Conference (EBCC) in Hamburg, Germany.

The data presented show that the vaccine is well tolerated and safe and that it induces significant HER-2 specific antibodies in breast cancer patients. Based on these results, Pharmexa plans the continued development of the vaccine through additional clinical investigations in the second half of 2004.

Pharmexa is presenting the full results from the clinical phase I trial with the HER-2 Protein AutoVac™ vaccine conducted at the Ireland Cancer Center in Cleveland, Ohio and the Magee Women’s Hospital in Pittsburgh, Pennsylvania. The vaccine is designed to induce antibody responses against the HER-2 protein that is over expressed in many human cancers, including some cancers of the breast.

Breast cancer patients received 4 injections of the vaccine formulated in a standard aluminium adjuvant. HER-2 specific antibody responses were detected in 6 out of 10 patients in the trial. The first responses were detected after only 2 injections and were significantly boosted following subsequent immunisations. Additional responders were also detected after the 3rd and 4th immunisations.

The peak antibody concentration detected in patient sera was approximately 2 micrograms per millilitre and the average for all 6 responders was 0.8 micrograms per millilitre with a decline to approximately half the peak value within 4 weeks following cessation of treatment. The vaccine was well tolerated and there were no serious safety concerns associated with the treatment. Dr. Adam Brufsky, principal investigator at Magee Women’s Hospital in the US said of the trial: “These are very promising phase I results, with a good safety profile, as well as significant immune responses. This could lead to the development of an effective vaccine for HER-2 positive breast cancer patients. I am looking forward to the results from Pharmexa’s planned Phase II study starting later this year that is designed to evaluate the clinical efficacy of the vaccine.” Jakob Schmidt, Chief Executive Officer says: ”We are very pleased with these results from our first trial with the HER-2 Protein AutoVac™ product.

These are significant immune responses that demonstrate the power of the AutoVac™ technology to bypass tolerance to the HER-2 protein in cancer patients. The results also show that the treatment is safe and well tolerated by the patients.” Pharmexa is currently planning a phase II trial, which is expected to commence in the second half of 2004. Preliminary results from this study are expected by mid 2006.