Pharmexa: Promising Preliminary Results with Breast Cancer Vaccine

HORSHOLM, DENMARK


HORSHOLM, Denmark, Aug. 16, 2005 (PRIMEZONE) -- Summary: Pharmexa has seen promising preliminary results from a phase II trial of the company's breast cancer vaccine and received approval to start an additional phase II trial of the vaccine.

Signs of tumour effect with the HER-2 Protein AutoVac(TM) vaccine in breast cancer:

Pharmexa has now received data from the first seven breast cancer patients in a phase II trial of the HER-2 Protein AutoVac(TM) vaccine formulated together with the adjuvant Alhydrogel. All seven patients were recruited and treated in Poland. Two out of seven treated patients have shown signs of tumour effect (a reduction of the tumour). These patients are still in treatment and will remain in treatment until their tumours progress. Two additional patients showed stable tumours after eight weeks at which time the treatment was stopped according to the protocol due to a lack of a measurable antibody response, but the period was too short to say whether this constituted an effect. With due reservation for the numbers involved, the preliminary data are encouraging and compare favourably with results observed with the antibody Herceptin as monotherapy in a comparable patient population. No adverse events were observed in relation to the treatment.

Antibody response after eight weeks of treatment was a criterion for continued treatment in the trial protocol. However, the majority of the patients turned out to have high concentrations of circulating HER-2 receptor molecules in the blood, which interfered with the antibody assay and made it difficult to determine their antibody levels accurately. Consequently, the trial cannot continue under the current protocol. However, given the promising clinical results seen so far, Pharmexa is considering together with its advisors how the study may continue with a re-designed trial protocol.

Approval in Poland and Hungary:

Pharmexa has obtained approval from the relevant authorities in Hungary and Poland to start the second phase II trial where the HER-2 Protein AutoVac(TM) vaccine is induced together with the adjuvant QS-21. Pharmexa has extended the number of trial centres in Poland and will submit applications to the authorities in Romania and Russia in order to open centres in these two countries as well. It is expected that no centres in Hungary will be opened since a recent change in reimbursement rules will make patient recruitment difficult here.

New design as a consequence of promising results:

As a consequence of the promising preliminary results Pharmexa has changed the protocol design for the second planned phase II trial so that the patients can continue treatment until progression, irrespective of their measured antibody levels. This change constitutes a significant strengthening of the protocol design for the second phase II trial and reflects the company's increased expectations to the HER-2 Protein AutoVac(TM) vaccine. That means that the trial will now only require 40 patients rather than 50 in order to obtain statistically significant data. All in all Pharmexa still expects to finalise the phase II program late in 2006. It is expected that the recently approved trial where the vaccine is formulated together with QS-21 will be concluded first.

Briefly about the phase II program and the HER-2 Protein AutoVac(TM) vaccine:

The first phase II trial tests the HER-2 Protein AutoVaca vaccine formulated in Alhydrogel adjuvant. The second Phase II trial will test the same vaccine in combination with QS-21, a proprietary adjuvant Pharmexa has licensed from Antigenics. QS-21 is generally considered a stronger adjuvant than Alhydrogel and is likely to lead to a stronger immune response. The purpose of running two parallel phase II trials is to generate as much information as possible about the relationship between vaccine dose, adjuvant, immune response and effect.

Patients in the second phase II trial will receive four initial immunisations over a six week period with 1.25 milligram HER-2 Protein AutoVac(TM) formulated with Alhydrogel adjuvant and mixed with QS-21 adjuvant, followed by booster immunisations every four week for up to 26 weeks. The trial will be carried out at 10-15 cancer research centres in Poland, Romania and Russia. According to the plan the centres will recruit 40 patients with active HER-2 positive breast cancer. Applications will be filed in Romania and Russia in the next few weeks.

Jakob Schmidt, CEO says: "It is important to emphasise that these results are preliminary and that we need to await the conclusion of the entire phase II program before we can say with any degree of certainty that the AutoVac(TM) concept is effective in breast cancer. However, we had not expected to see signs of efficacy so early in the trial -- our trial design was not even geared for it, and therefore it has been adjusted. Generally speaking the new results have increased our chances of a positive result from our phase II program in breast cancer."

Hoersholm, August 16, 2005



 Jakob Schmidt
 Chief Executive Officer

 Further information:
 Jakob Schmidt, Chief Executive Officer
 Tel. +45 4516 2525

Note to editors: Pharmexa A/S (CSE:PHARMX) is a leading company in the field of active immunotherapy for the treatment of serious chronic diseases. Pharmexa's proprietary technology platforms are broadly applicable, but the company has focused its resources on cancer and chronic inflammatory diseases, with research and development programs targeted towards various cancer forms, rheumatoid arthritis, bone degeneration, Alzheimer's disease andothers. Its leading programs are GV1001, a peptide vaccine about to enter phase III trials in pancreatic cancer and HER-2 AutoVac(TM)Protein, a recombinant protein vaccine in phase II against breast cancer. Collaborative agreements include Schering-Plough, H. Lundbeck and Bavarian Nordic.

The HER-2 Protein AutoVac(TM) vaccine has been designed to generatean antibody response against the HER-2 protein, which is over-expressed in many cancer forms including some breast cancers. Pharmexa has previously reported promising Phase I data showing that the vaccine is safe and capable of generating an antibody response. This Phase I trial was not intended to investigate tumour response. As a next step in the development of the vaccine, the current Phase II clinical program will investigate the clinical benefit of the vaccine.