October 3, 2006
HIV morbidity and mortality have been greatly reduced by antiretroviral therapy, yet the best sequence of regimens and implications of initial regimen for long-term therapeutic success are not well defined. In INITIO -- a large international randomized trial -- the study authors compared antiretroviral therapy with two nucleoside analogue reverse transcriptase inhibitors (didanosine + stavudine) plus either a non-nucleoside reverse transcriptase inhibitor (efavirenz, EFV) or a protease inhibitor (nelfinavir, NFV), or both (EFV/NFV) in HIV-1-infected patients who had not previously received antiretroviral therapy. Primary outcomes were proportion with undetectable HIV RNA in plasma and change in CD4 count from baseline at three years; analyses were by intention-to-treat.
In the study, 911 patients (297 EFV, 311 NFV, 303 EFV/NFV) were followed. At three years, the EFV group had the highest proportion of HIV RNA less than 50 copies per mL (188 [74 percent] EFV, 162 [62 percent] NFV, 155 [62 percent] EFV/NFV; p=0.004). Mean (95 percent confidence interval) increases in CD4 count were 316x106 cells per L (288-343) for EFV, 289x106 per L (262-316) for NFV, and 274x106 cells per L (231-291) for EFV/NFV (p=0.1). Compared to other groups, fewer EFV participants stopped adequate therapy for more than 30 days (p=0.005). The EFV/NFV group had shorter time to halting the initial regimen (p"Starting antiretroviral therapy with a three-drug/two-class regimen including efavirenz was better than starting with regimens including nelfinavir or efavirenz plus nelfinavir in terms of virological suppression and durability of the initial regimen. The shorter time on adequate antiretroviral therapy or to a treatment-modifying adverse event might explain the absence of additional benefit for the four-drug regimen," the authors concluded.