Immunological, virological and clinical response in patients infected with HIV after highly active antiviral therapy with nelfinavir:: prospective cohort study

INTRODUCTION. To assess the long-term effectiveness, safety and response-related factors in a cohort of HIV-infected persons receiving antiretroviral therapy containing nelfinavir. DESIGN AND SETTING. Prospective, non-randomized multicenter study. METHOD. A total of 792 patients were included: 254 (32.1%) treatment-naive patients and 538 (67.9%) patients previously treated with protease inhibitors who were switched to a nelfinavir-containing regimen due to virological failure or intolerance. Factors related to virological response and to treatment failure were assessed by standard survival techniques and Cox proportional risk models. RESULTS. Nelfinavir was well tolerated; treatment had to be interrupted in only 57 patients (7.1%) because of toxicity. During a median follow-up of 12 months, 31 patients (3.9%) experienced a new AIDS-defining event or death, and 463 (58.4%) showed immunological response. Overall, 52% patients achieved plasma HIV-1 RNA levels below 500 copies/mL (57% of naive and 49% of previously treated patients), but a high rate of virological rebound (24% and 49%, respectively) was observed. Low baseline viral load and few prior treatments were factors related to virological response. Naive treatment status and a high increase in CD4 cell count were predictive of longer viral response. CONCLUSIONS. Highly active antiretroviral therapy with a nelfinavir-containing regimen was associated with favorable virological response in nearly half of previously treated patients, and most experienced clinical and immunological benefits. Nevertheless, the limited duration of virological response indicates the need for new alternative drugs.