Withdrawing inactive NRTIs in HIV-1 subjects with suppressed viraemia: a randomized trial.

Background: Extensively pretreated subjects with virological failure (VF) may receive salvage regimens containing NRTIs with only residual or no activity. Once virological suppression is achieved, their contribution remains elusive.

Methods: This was a multicentre, randomized, prospective study. Subjects with at least one prior VF, HIV-1 RNA 50 copies/mL for ≥6 months and receiving a regimen with at least two active drugs (one of them a boosted PI) were randomized 1:1 to stop (experimental arm) or maintain (control arm) NRTIs. EudraCT: 2012-000198-21.

Results: Ninety subjects were randomized (experimental, n = 45; and control, n = 45). The mean age was 50 years, 80% were male, the mean CD4+ cell count was 542 cells/mm(3) and the median number of prior VFs was 3. Seventy-four subjects (82%) harboured the mutation M184V/I and the median number of thymidine-associated mutations was 3 (IQR: 0-4). In the experimental arm, thirty-two (71%) subjects removed one NRTI and 13 (29%) subjects removed two. Twenty-two of 45 (49%) discontinued tenofovir disoproxil fumarate. Forty-one of 45 (91.1%, experimental arm) and 44 of 45 (97.8%, control arm) had HIV-1 RNA 50 copies/mL at 48 weeks (difference: -6.7%; 95% CI: -17.4, 4.1). In a post-hoc analysis allowing NRTI reintroduction, efficacy rates were 95.6% and 97.8%, respectively (difference: -2.2%; 95% CI: -7.2, 2.7). Rates of discontinuation at 48 weeks were 2% in both arms. One subject developed a late VF with resistance selection.

Conclusion: Ninety subjects were randomized (experimental, n = 45; and control, n = 45). The mean age was 50 years, 80% were male, the mean CD4+ cell count was 542 cells/mm(3) and the median number of prior VFs was 3. Seventy-four subjects (82%) harboured the mutation M184V/I and the median number of thymidine-associated mutations was 3 (IQR: 0-4). In the experimental arm, thirty-two (71%) subjects removed one NRTI and 13 (29%) subjects removed two. Twenty-two of 45 (49%) discontinued tenofovir disoproxil fumarate. Forty-one of 45 (91.1%, experimental arm) and 44 of 45 (97.8%, control arm) had HIV-1 RNA 50 copies/mL at 48 weeks (difference: -6.7%; 95% CI: -17.4, 4.1). In a post-hoc analysis allowing NRTI reintroduction, efficacy rates were 95.6% and 97.8%, respectively (difference: -2.2%; 95% CI: -7.2, 2.7). Rates of discontinuation at 48 weeks were 2% in both arms. One subject developed a late VF with resistance selection.