Time to Viral Rebound and Safety After Antiretroviral Treatment Interruption in Postpartum Women Compared with Men

Objective(s): The short-term safety of treatment interruptions, a necessary part of cure studies, is not well established, particularly in women. We explored viral rebound kinetics and safety in a group of postpartum women discontinuing ART and compared results to men in historical interruption trials.

Design: Prospective evaluation of time to virologic rebound.

Methods: One thousand and seventy-six asymptomatic, virally suppressed, postpartum women living with HIV enrolled in the PROMISE trial with baseline CD4 cell counts at least 350 cells/μl underwent antiretroviral treatment (ART) discontinuation. Proportion with virologic suppression at weeks 4 and 12 were compared with participants in ACTG treatment interruption trials (91% male population).

Results: In PROMISE, using interval censored methods, the estimated median time to HIV viral rebound was 2 weeks. An estimated 6% of women would remain virally suppressed at 30 weeks. Of those who had viral rebound by 30 weeks (N = 993), less than 4% experienced grade 3 or higher laboratory events, and 1% experienced WHO stage 2 or higher clinical events. Overall, less than 1% of participants progressed from WHO Stage 1 to Stage 2 or higher after discontinuation of ART, and 3.9% experienced a decline in CD4 cell count to less than 350 cells/μl or local treatment guidelines. A significantly higher proportion of women in PROMISE (25.4%) were virologically suppressed (<400 copies/ml) at 12 weeks compared with ACTG NWCS 371 participants (6.4%).

Conclusion: Temporary treatment interruptions in healthy, HIV-infected women with high CD4 cell counts can be well tolerated. Potential sex differences need to be considered in cure studies examining time to virologic rebound.