Efficacy and safety of tenofovir-containing antiretroviral therapy in women who acquired HIV while enrolled in tenofovir gel prophylaxis trials.

Background: We assessed whether women who acquired HIV during tenofovir gel prophylaxis trials can be safely and effectively treated with tenofovir-containing anti-retroviral therapy (ART). Methods: Between May 2011 and October 2014, HIV seroconvertors from two tenofovir gel trials were recruited when eligible for ART (CD4(+) T-cell count <350 cells/mu l, pregnancy or AIDS-defining illness). Women were randomized to tenofovir-containing (tenofovir + lamivudine/emtricitabine + efavirenz) or tenofovir-sparing (zidovudine + lamivudine/emtricitabine + efavirenz) antiretroviral treatment regimens. The proportion with virological suppression, adverse events and drug switches were compared. Results: Fifty-nine women were enrolled and followed-up for median 18 months (IQR 6-24). Twenty-nine women (7 tenofovir gel exposed, 22 tenofovir gel unexposed) were randomized to a tenofovir-containing and 30 (9 tenofovir gel exposed, 21 tenofovir gel unexposed) to a tenofovir-sparing regimen. Median baseline CD4(+) T-cell count and viral load (VL) were 345 cells/mu l (IQR 280-423) and 4.5 log copies/ml (SD 0.79), and did not differ by ART assignment. Overall VL suppression rates were 88.0% and 78.3% at 6 months (P=0.454) and 85.7% and 79.0% at 12 months (P=0.689) in women on the tenofovir-containing and tenofovir-sparing regimens, respectively. Toxicity-related drug switches were more frequent in women on the tenofovir-sparing than tenofovir-containing regimen (36.7% versus 0.0%, P<0.001). Conclusions: Preliminary data show that tenofovir-containing ART was effective and more tolerable in HIV seroconvertors from tenofovir gel prophylaxis trials and may be considered for use in women with prior tenofovir gel exposure.