GENENTECH AND BIOCINE GP120 AIDS VACCINES ENTERING NIAID- SPONSORED PHASE II

GENENTECH AND BIOCINE GP120 AIDS VACCINES ENTERING NIAID- SPONSORED PHASE II trials that will soon start accruing subjects at five sites in Seattle, Baltimore, St. Louis, Nashville and Rochester, the National Institute of Allergy and Infectious Diseases announced Dec. 1. Conducted through NIAID's AIDS Vaccine Evaluation Units, the double-blind, placebo-controlled study will test the ability of Genentech's and Biocine's respective envelope- based gp120 vaccine candidates to prevent HIV infection in 320 seronegative adult men and women between 18 and 60 years of age. Both the Genentech and the Biocine products, which are based on AIDS isolates similar to strains commonly found among infected individuals in the U.S., have been shown to be safe and well- tolerated in Phase I trials. Results of the Phase I trials were presented at the VIII International AIDS Conference in Amsterdam in July by investigators from San Francisco General Hospital (for Biocine, a Chiron/Ciba-Geigy joint venture) and from Johns Hopkins Center for Immunization Research for Genentech ("The Pink Sheet" Aug. 3, T&G-9). All subjects will be randomly assigned to receive either one of the candidate vaccines or one of two adjuvants -- alum, which is included in Genentech's product, or MF59, an experimental immune system stimulator used in the Biocine formulation. MF59 has been studied in early clinical trials. Commenting on the NIAID trial at the Robertson, Stephens Healthcare Conference in New York City Dec. 2, Chiron CEO Ed Penhoet, PhD, called the trials a "shoot-out" between Chiron and Genentech in which he claimed Chiron has the advantage due to its proprietary adjuvant. Genentech's use of an alum adjuvant, Penhoet asserted, requires the use of "about 25 times more antigen than we do to get responses which still are not as high as what we are seeing. So we think we get higher antibody response and we get those antibody responses with a much lower quantity of material," the Chiron exec told the investor conference. In a press statement on the status of its gp120 vaccine, Genentech noted that all volunteers in the Hopkins study receiving the vaccine showed increases in antibodies to gp120 and that nine of 10 volunteers receiving a high dose of the vaccine (300 mcg) "produced antibodies capable of neutralizing the HIV-1 virus." In the trial, an initial intramuscular inoculation will be given to participants at the start of the study, followed by booster injections at one and six months. Follow-up of study volunteers will be about one year post-immunization. NIAID noted that "minorities and people representing several different populations hardest hit by the epidemic will especially be encouraged to enroll." Specifically, teens and young adults who have attended sexually transmitted disease clinics within the last three months will be included in the trial, as well as individuals who have used intravenous drugs within the last three years, homosexual males and heterosexual individuals with HIV- seropositive partners. Men and women at low risk of acquiring HIV will also be enrolled, and all study participants will be counseled to avoid behavior that puts them at risk for HIV infection.