Viral rebound and emergence of drug resistance in the absence of viral load testing: a randomized comparison between zidovudine-lamivudine plus Nevirapine and zidovudine-lamivudine plus Abacavir.

BACKGROUND: We investigated virological response and the emergence of resistance in the Nevirapine or Abacavir (NORA) substudy of the Development of Antiretroviral Treatment in Africa (DART) trial. METHODS: Six hundred symptomatic antiretroviral-naive human immunodeficiency virus (HIV)-infected adults (CD4 cell count, <200 cells/mm(3)) from 2 Ugandan centers were randomized to receive zidovudine-lamivudine plus abacavir or nevirapine. Virology was performed retrospectively on stored plasma samples at selected time points. In patients with HIV RNA levels >1000 copies/mL, the residual activity of therapy was calculated as the reduction in HIV RNA level, compared with baseline. RESULTS: Overall, HIV RNA levels were lower in the nevirapine group than in the abacavir group at 24 and 48 weeks (P < .001), although no differences were observed at weeks 4 and 12. Virological responses were similar in the 2 treatment groups for baseline HIV RNA level <100,000 copies/mL. The mean residual activity at week 48 was higher for abacavir in the presence of the typically observed resistance pattern of thymidine analogue mutations (TAMs) and M184V (1.47 log(10) copies/mL) than for nevirapine with M184V and nonnucleoside reverse-transcriptase inhibitor mutations, whether accompanied by TAMs (0.96 log(10) copies/mL) or not (1.18 log(10) copies/mL). CONCLUSIONS: There was more extensive genotypic resistance in both treatment groups than is generally seen in resource-rich settings. However, significant residual activity was observed among patients with virological failure, particularly those receiving zidovudine-lamivudine plus abacavir.

Early antiretroviral therapy in children perinatally infected with HIV: a unique opportunity to implement immunotherapeutic approaches to prolong viral remission.

From the use of antiretroviral therapy to prevent mother-to-child transmission to the possibility of HIV cure hinted at by the Mississippi baby experience, paediatric HIV infection has been pivotal to our understanding of HIV pathogenesis and management. Daily medication and indefinite antiretroviral therapy is recommended for children infected with HIV. Maintenance of life-long adherence is difficult and the incidence of triple-class virological failure after initiation of antiretroviral therapy increases with time. This challenge shows the urgent need to define novel strategies to provide long-term viral suppression that will allow safe interruption of antiretroviral therapy without viral rebound and any associated complications. HIV-infected babies treated within a few days of birth have a unique combination of a very small pool of integrated viruses, a very high proportion of relatively HIV resistant naive T cells, and an unparalleled capacity to regenerate an immune repertoire. These features make this group the optimum model population to investigate the potential efficacy of immune-based therapies. If successful, these investigations could change the way we manage HIV infection.

Nevirapine use in HIV-1-infected children.

OBJECTIVES: To evaluate the safety, efficacy, and clinical, virological, and immunological responses in HIV-1-infected children receiving nevirapine as part of combination antiretroviral therapy (ART). METHODS: A review of case notes of all HIV-1-infected children 96 weeks after starting nevirapine, under a national compassionate access scheme between August 1997 and March 1999 in the UK. Nevirapine was dosed according to the manufacturer's guidelines. RESULTS: Seventy-four children (36 boys, 28 naive to ART) were enrolled, with a median age of 5.2 years, viral load of 5.1 log copies/ml and CD4 lymphocyte count of 13.5%. The liquid formulation and tablets of nevirapine were well tolerated. The proportions of patients achieving undetectable viral load levels at weeks 12, 24, 48 and 96 were 30, 40, 36 and 33%, respectively (intention-to-treat analysis). Of children not on a protease inhibitor who received more than 300 mg/m2/day of nevirapine, 60% had undetectable viral loads at week 96, compared with 17% on recommended doses. Outcomes were similar for patients receiving nevirapine once or twice daily. CD4 cell count percentages increased significantly, with median values sustained above 25% by week 48 onwards. Z-scores for weight and height increased significantly during 96 weeks of treatment. Rash occurred in 20%, of which four (5%) were severe. There were no cases of Stevens-Johnson syndrome. CONCLUSION: Nevirapine was mostly well tolerated, and was associated with encouraging clinical and immunological responses. Virological responses in this cohort support the use of nevirapine doses greater than 300 mg/m2/day, which is higher than currently recommended by the manufacturers.