Front-Line AIDS Drugs Show Staying Power: Study

A new study offers encouraging news about first-line HIV/AIDS treatments and the development of drug-resistant virus.

British researchers examined data on 7,916 HIV patients taking the standard three-drug cocktail of nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. They found that 167 had developed extensive resistance to all three drug classes. The study population had a 9.2 percent chance of developing three-drug resistance after 10 years, the authors reported.

The study's findings are particularly welcome news for the developing world. When primary treatment fails, doctors must turn to second- and third-line drugs. In resource-poor locales, these are much more expensive and difficult to obtain. "In such settings, only one or two regimes are normally available, which results in disastrous consequences when these regimes fail," according to a commentary published with the study.

The news, however, comes with caveats:

• While the British patients typically started therapy early, the rate of failure was higher for those who started treatment after their CD4 cell levels fell below 200. In developing nations, AIDS drugs are rarely administered before CD4 cells fall below 200.
• Among patients who failed on the three-drug cocktail, 90 percent showed resistance to seven first-line drugs, and 58 percent of those failed on second-line therapies as well.

The full report, "Risk of Extensive Virological Failure to the Three Original Antiretroviral Drug Classes over Long-Term Follow-up from the Start of Therapy in Patients with HIV Infection: An Observational Cohort Study," and the commentary, "A Wake-Up Call for Global Access to Salvage HIV Drug Regimens," were published in The Lancet (2007;370(9603):1923-1928 and 1885-1887).

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