Continued indinavir versus switching to indinavir/ritonavir in HIV-infected patients with suppressed viral load

Objective: To compare continued indinavir (IDV) 8-hourly (q8h) with switching to indinavir/ritonavir (IDV/RTV) 12-hourly (q12h) in HIV-positive patients having suppressed viral load with IDV q8h plus two nucleoside reverse transcriptase inhibitors (NRTI). Design: Multicentre, international, randomized, open-label study enrolling HIV-1 infected patients on IDV 800 mg q8h plus two NRTI with CD4 cell counts greater than or equal to 100 X 10(6)/l and plasma HIV RNA < 500 copies/ml for greater than or equal to 3 months. Methods: Patients were randomized to continue on the same regimen or to switch to IDV plus liquid RTV (IDV/RTV 800 mg/100 mg q12h). Primary endpoint was the proportion of patients remaining < 500 copies/ml at 48 weeks. Results: A total of 323 patients (IDV/RTV, 162; IDV, 161) were evaluable. At 48 weeks, the proportions of patients with plasma HIV RNA < 500 copies/ml were 93%, 88% and 58% in the IDV/RTV arm versus 92% (P=1), 86% (P=0.87) and 74% (P = 0.003) in the IDV arm using on-treatment (OT) and intent-to-treat (ITT) [switches included (ITT, S = 1) and switches = failure (ITT, S = F)] analyses respectively. Mean increase in CD4 cell count was 88 X 10(6)/cells/l (IDV/RTV arm) and 60 X 10(6) cells/l (IDV arm) (P = 0.08). More patients discontinued study medication. due to adverse events in the IDV/RTV arm than in the IDV arm (P < 0.001). Conclusions: Equivalence of continuing IDV q8h versus switching to IDV/RTV (liquid) q12h in suppressed stable patients was demonstrated by OT and ITT S = I analyses. However, the IDV q8h arm performed better when discontinuations were classified as failures. IDV/RTV q12h can be convenient and equally effective for patients able to tolerate it. (C) 2003 Lippincott Williams Wilkins.