Alternation of antiretroviral drug regimens for HIV infection. A randomized, controlled trial.

Background: Mathematical modeling has suggested that alternating antiretroviral regimens while patients' viral load remains suppressed would minimize HIV resistance mutations.

Results: Patients receiving standard-of-care regimens A and B did not differ. Virologic failure over 48 weeks was delayed in the alternating therapy group compared with the pooled standard-of-care group (incidence rate, 1.2 events/1000 person-weeks [95% CI, 0.3 to 3.6 events/1000 person-weeks] vs. 4.8 events/1000 person-weeks [CI, 2.9 to 7.4 events/1000 person-weeks]; P = 0.01). Genotypic drug resistance emerged in 79% of patients in the standard-of-care group who experienced on-therapy treatment failure. Patients in the standard-of-care and alternating therapy groups had similar CD4 cell counts, frequency of adverse events, reported drug adherence, and quality of life.

Conclusion: Patients receiving standard-of-care regimens A and B did not differ. Virologic failure over 48 weeks was delayed in the alternating therapy group compared with the pooled standard-of-care group (incidence rate, 1.2 events/1000 person-weeks [95% CI, 0.3 to 3.6 events/1000 person-weeks] vs. 4.8 events/1000 person-weeks [CI, 2.9 to 7.4 events/1000 person-weeks]; P = 0.01). Genotypic drug resistance emerged in 79% of patients in the standard-of-care group who experienced on-therapy treatment failure. Patients in the standard-of-care and alternating therapy groups had similar CD4 cell counts, frequency of adverse events, reported drug adherence, and quality of life.