Vaccine Victory (Of Sorts), Or "Yes, Only Not In My Backyard." Genentech's Don Francis Has the Last Word. WHO gave the green light to vaccine prevention studies in developing countries with the very products judged by US officials to be unlikely to confer protection. Southeast Asia and South America are lining up as the most likely testing grounds, and trials are expected to begin shortly. The US Department of Defense is said to be preparing trials of Chiron's gp120 product for Thailand, while Genentech is reported to have plans for a phase III study of its gp120 in Brazil.
Inching Closer To An Animal Model for HIV. Jay Levy and colleagues report progress towards the quest for a laboratory animal that can be infected (and made ill) with HIV. Although the success came with HIV-2 rather than HIV-1, four out of six baboons not only seroconverted but developed lymphadenopathy, cachexia, lymph node abnormalities and skin lesions. Chimpanzees and pig-tailed -macaques have been the principal nonhuman primates currently used to study HIV infection, but (for unknown reasons) infection in these species does not progress to AIDS-like disease or death. Harvard's Norman Letvin has also infected baboons.
Like Cattle Off the Cliff... G.D. Searle's lead protease inhibitor crashed and burned late last month. While it looked "promising" in pre-clinical work, SC-52,151 showed absolutely no anti-HIV activity in humans, after 2 weeks of study. What with the apparent potency of Roche's compound approaching that of the late lame duck Congress, this latest development leaves precious few protease inhibitors left for the final analysis. And, as a recent meeting with Merck has revealed, those that do remain can be expected to quickly encounter not only drug-resistant mutant virus but mutants cross-resistance to many other PIs in a big hurry. The field of a dozen or so potential agents may have been reduced overnight to only one or two.