Jenner Technologies Announces Phase I/II Clinical Results of Prostate Cancer Vaccine.

SAN RAMON, Calif.--(BW HealthWire)--July 8, 1997--Jenner Technologies Inc. Tuesday announced results from four Phase I/II clinical trials of OncoVax-P(TM), a vaccine for therapy of prostate cancer.

The vaccine was well tolerated and demonstrated clinical benefit in half of patients with advanced hormone refractory prostate cancer, according to Lynn E. Spitler, M.D., the company's chief scientific officer.

OncoVax-P consists of recombinant Prostate Specific Antigen (PSA) combined with an adjuvant (lipid A) formulated into liposomes to target the immune system and induce a potent immune response to patients' tumors.

"These trials have shown it is possible to induce an immune response to PSA, even though PSA is a 'self antigen' to which the body would not normally respond," said Spitler.

The results were presented at the 10th Annual Meeting of the Cancer Biotherapy Research Group in Omaha, Neb. The OncoVax-P clinical trials were conducted by Principal Investigator David Harris, M.D., at The Lankenau Hospital, Wynnewood, Pa.

The first trial involved administration of the vaccine by traditional intramuscular injection. In the second trial, the vaccine was administered intravenously in order to gain wider access to the sites of the immune response. In these two trials no serious side effects were seen and immune responses to PSA were induced.

In the third trial, an adjuvant (GM-CSF) was added to stimulate antigen presentation. In the fourth trial, patients were pretreated with cylophosphamide to diminish suppressor cell activity. The vaccine was administered intracutaneously with addition of BCG (Bacillus Calmette-Guerrin) at the site of vaccine administration. These two regimens showed further enhancement of immune responses compared with the first two trials.

Five patients in each trial received three immunizations over 30 to 60 days, each consisting of 100 micrograms of recombinant PSA with 200 micrograms lipid A in a 1 ml liposomal formulation.

The first two patients who entered the first trial, which began in 1995, had advanced hormone refractory prostate cancer. They are receiving continuing courses of the vaccine, have stable disease, and are able to carry on normal activities more than 1-1/2 years after starting vaccine therapy, according to Spitler.

Expanded Phase II trials are expected to commence in the fourth quarter of 1997 to further evaluate safety and efficacy of OncoVax-P and define the patient population for the Phase III pivotal trial expected to begin in 1998.

In 1994, the company filed the earliest patent application for vaccines for the prevention or therapy of prostate cancer using antigens over-represented in prostate cancer including PSA, prostate specific membrane antigen (PSMA), prostatic acid phosphatase (PAP) and peptide fragments thereof.

"The patent application was prescient in that it was filed before it was generally recognized in the scientific community that an antigen produced intracellularly and secreted could be used in an effective vaccine to induce cytotoxic T-cells which would kill tumor cells," said Anthony E. Maida, CEO of Jenner Technologies.

"Our strategy to fortify and protect our proprietary position regarding vaccines for prostate cancer involves early filings and diligent pursuit of the patent applications worldwide," Maida said.

Jenner Technologies of San Ramon is involved in the development and clinical evaluation of immunotherapies for patients with cancer. The focus is on treating patients who have a minimal tumor burden in an effort to slow disease progression and improve survival and quality of life in patients with cancer.

The company has two product platforms for cancer immunotherapy, one involving the use of recombinant vaccines and the other involving macrophage activators. One of the macrophage activators is in a pivotal Phase III trial nationwide in patients with osteogenic sarcoma, and a second macrophage activator is in preclinical development.

Jenner Technologies is located at 2010 Crow Canyon Place, Suite 100, San Ramon, Calif. 94583-1344; phone [phone]; fax [phone]; e-mail [e-mail]; Web site http://www.jennertech.com .

CONTACT: Jenner Technologies Inc., San Ramon

Anthony E. Maida III, 510/824-3150

Lynn E. Spitler, 415/435-9861