AIDS therapy: new push for clinical trials.
There is clearly a long way to go before an effective therapy is developed for acquired immunodeficiency syndrome (AIDS). However, in the US, federal efforts in this area have stepped up in recent months. The US Congress has approved a massive infusion of funds--a budget of US$240 million, of which a substantial portion has been earmarked for testing drugs that show some promise against the AIDS virus. The National Institute of Allergy and Infectious Diseases (NIAID) is establishing a network of medical centers to carry out phase II trials of promising compounds that have undergone limited toxicity testing, and 2000 patients are expected to be enrolled in these trials by late 1986. In addition, to provide coordination and focus to the effort, the National Institutes of Health (NIH) has established a drug evaluation committee. 3 major difficulties face AIDS researchers. First, the AIDS virus becomes part of the cell it infects, suggesting that it may never be removed entirely from the body. Second, the virus is now known to infect the brain, meaning that drugs must cross the blood-brain barrier. Third, even if a drug can be found to interrupt the life cycle of the virus, the patient's immune system may already have been destroyed, indicating a need for additional therapy to reconstitute the immune system. It appears likely that drugs will have to be administered on an intermittent basis throughout an AIDS patient's life. Of the 4 compounds currently in limited clinical trials in the US (suramin, azidothymidine, ribavirin, and HPA-23), none seems to offer much clinical improvement when given in the late stages of AIDS. In the future, it may be possible to develop drugs that are targeted toward specific features of the life cycle of the AIDS virus. The hope is that, if a safe and effective antiviral drug can be given to AIDS patients before their immune systems are destroyed, their immune functions may regenerate spontaneously or be reconstituted through additional drug therapy.