New AIDS Drugs Are Working, but More R&D Still Needed
Anonymous, Drug Topics
Scientists gathered in Washington, D.C., for the 4th Conference on Retroviruses & Opportunistic Infections continued to express optimism about the outcome for patients on the new triple-therapy regimens containing protease inhibitors. But researchers believe that the pharmaceutical industry must still think about adding new drugs, which hit different molecular targets such as integrase, to try to outwit the HIV virus.
Some highlights from the meeting reported by researchers: A vaccine against HIV-1 is considered the ultimate goal, but it is not ready for prime time as yet. The AIDS Vaccine Evaluation Group, however, reported on a canarypox vaccine generating neutralizing antibodies in 31 of 37 people tested, at up to a year, indicating that a vaccine in high-risk populations may not be too far off.
Studies continue to confirm the efficacy of triple-therapy cocktails for people within all stages of HIV infection including AIDS. In the first such report on the use of triple therapy in patients with far-advanced AIDS, Martin Hirsch of Harvard Medical School said that 55 out of 85 people with fewer than 50 CD4 cells/mm, a laboratory result indicating very advanced disease, showed a remarkable response to a combination of indinavir (Crixivan, Merck), zidovudine (Retrovir, Glaxo Wellcome), and lamivudine (Epivir, Glaxo Wellcome). In the 65% of the group responding, blood levels of HIV became undetectable after 24 weeks of the combination therapy. This group is part of a group of 320 long-infected patients with CD4 counts at or below 500 mm who have now been followed for six months, and who were on this three-drug cocktail. In the overall group there was an 85% response rate.
There's been a significant drop in AIDS mortality. In New York City, which has about one-sixth of all AIDS cases in the country, deaths from AIDS dropped 30% between 1995 and 1996. Health department researcher Mary Ann Chaisson attributed the reduction in mortality to the greater availability of new drugs and predicted that deaths could drop further with the recent advent of the protease inhibitors as part of the AIDS armamentarium. …