Indinavir is the third drug in this class of AIDS protease inhibitors that this committee has recommended for approval. Protease inhibitors interrupt a key step in the chemical sequence by which HIV replicates.
The committee primarily discussed two controlled clinical trials that the agency has been reviewing to determine the drug's safety and effectiveness in treating HIV infection and AIDS. The trials involved a total of 490 patients and studied one group receiving indinavir alone, another group receiving the drug in combination with AZT, and a third group treated with just AZT. The committee also discussed the data from a small study that evaluated indinavir in combination with two nucleoside analogues, AZT and 3TC.
In the indinavir-only study arms, patients received 800 mg of indinavir three times per day. Patients" CD4 cell counts (the number of these infection-fighting cells per milliliter in patients' blood) and viral load (the amount of detectable virus in the blood stream) were monitored to determine the drug's effectiveness for 24 weeks of study.
Clinical data presented at the advisory committee meeting indicated that patients in the indinavir-only and combination therapy arms experienced a marked increase in their CD4 levels and had a marked decrease in their viral load.
Based on this data, the committee recommended that indinavir be granted accelerated approval, a regulatory mechanism under which the agency bases early marketing approval for a product on laboratory markers such as the CD4 cell counts until information about clinical endpoints such as delay in death or reduction of opportunistic infections is available.
Manufacturers of products granted accelerated approval must demonstrate within a reasonable period of time that the product provides true clinical benefit or the agency may withdraw the granted accelerated approval. Two trials are ongoing to evaluate the clinical benefits of indinavir.
Advisory committee recommendations are not binding, but the Agency often follows their recommendations.
Among, the major adverse events reported with indinavir therapy were infrequent kidney stones and frequent increases in bile production.
Information on other ongoing AIDS clinical trials are available through the Public Health Service's AIDS Clinical Trial Information Service at 1-800-TRIALS-A.