Treating Older HIV-1-infected Subjects With Cobicistat-boosted Darunavir in a 48-week Phase 3 Trial

Abstract

Background: An aging HIV-1-infected population warrants examination of the acceptability of individual antiretroviral regimens. In a previous study of ritonavir-boosted darunavir (ARTEMIS), similar safety/efficacy profiles were observed in younger (≤45 years) and older (>45 years) HIV-1-infected subjects.

Objective: To evaluate safety and efficacy outcomes in HIV-1-infected younger versus older subjects treated with cobicistat-boosted darunavir.

Method: In a 48-week, phase 3b, open-label trial, HIV-1-infected adults were administered darunavir 800 mg and cobicistat 150 mg once-daily with 2 nucleos(t)ide reverse transcriptase inhibitors (N[t]RTIs). Post hoc analyses examined safety and efficacy outcomes in subjects ≤45 and >45 years.

Results: Of 313 subjects, 76% were ≤45 years (median [range] age, 31 [18-45]) and 24% were >45 years (49 [46-72]). Baseline median (range) viral loads were 4.75 (2.6-6.8) and 4.83 (2.7-7.0) log10 copies/mL, and CD4+ counts were 379.0 (5-1473) and 310.5 (6-757) cells/mm3 in younger and older subjects, respectively. Through Week 48, similar proportions of younger and older subjects had ≥1 adverse event (AE; 93% vs 88%), ≥1 grade 2-4 AE possibly related to study drug (13% vs 15%), and discontinued study due to AE (3% vs 3%). At Week 48, 82% of younger and 78% of older subjects had viral load <50 copies/mL (95% CI of the difference: -7.4% to 13.8%). A higher proportion of older versus younger subjects took >4 concomitant medications during the study (69% vs 57%).

Conclusion: Safety and efficacy profiles of cobicistat-boosted darunavir with 2 N(t)RTIs were similar in HIV-1-infected subjects ≤45 and >45 years.

Keywords: Age; antiretroviral; cobicistat; darunavir; human immunodeficiency virus; polypharmacy; protease inhibitor.