ENOUGH EVIDENCE may exist to approve two analogues of zidovudine ([AZT] Retrovir, Burroughs Wellcome, Research Triangle Park, NC).
At issue is whether surrogate markers of disease progression, like CD4 cell counts, can substitute for clinical end points like death.
If so, data from ongoing trials might be collated into a convincing case. If not, it could be 2 years or more before traditional criteria are met.
The drugs ddC (dideoxycytidine, Hoffmann-LaRoche Inc, Nutley, NJ) and ddI (didanosine [formerly called dideoxyinosine], Bristol-Myers Squibb Company, Princeton, NJ) inhibit viral replication as does zidovudine, which is still the only licensed drug that fights the human immunodeficiency virus (HIV) linked with the acquired immunodeficiency syndrome (AIDS).
"Preliminary data show clear-cut drug activity," says Margaret Fischl, MD, who studies all three drugs as an investigator for the National Institutes of Health (Bethesda, Md) AIDS Clinical Trials Group.
All three can cause peripheral neuropathy. But ddI