The VIRGO Study: nevirapine, didanosine and stavudine combination therapy in antiretroviral-naive HIV-1-infected adults

The virological and immunological efficacy of the triple regimen containing nevirapine (once or twice daily), didanosine (once daily) and stavudine, i n antiretroviral-naive patients infected with HIV-1, was evaluated in an op en-label, prospective, non-randomized, multi-centre, 52-week study. The fir st 60 patients (VIRGO I) received nevirapine as the standard dose, 200 mg t wice daily; the subsequent 40 patients (VIRGO II) received nevirapine at a dose of 400 mg once daily. All patients received 400 mg of didanosine once daily and 40 mg of stavudine twice daily, adjusted for body weight. At base line, the median CD4 cell count and plasma viral load (pVL) were 414 cells/ mm(3) and 4.59 log(10) copies/ml in VIRGO I, and 412 cells/mm(3) and 4.87 l og(10) copies/ml in VIRGO II. Using an intent-to-treat, 'non-completer equa ls failure', analysis, 78% (95% CI, 68-88%) of patients in VIRGO I and 68% (95% CI, 53-83%) of those in VIRGO II had a pVL <500 copies/ml at 24 weeks; the proportions achieving a pVL of <50 copies/ml were 62% (95% CI, 50-74%) and 50% (95% CI, 35-65%), respectively. The week 24 median CD4 cell count increase was 168 cells/mm(3) (VIRGO I) and 139 cells/mm(3) (VIRGO II). At w eek 52, 39/45 (87%) of VIRGO I patients had pVL <500 copies/ml and 30/45 (6 7%) <50 copies/ml. Of the 100 patients, 44 experienced grade 2 to 4 adverse events; 20 permanently discontinued study medication because of an adverse event. Combination therapy with the three reverse transcriptase (RT) inhib itors stavudine, once-daily didanosine and either once- or twice-daily nevi rapine could be considered as an alternative option for first-line antiretr oviral therapy.