ViiV Healthcare announces investigational injectable cabotegravir is superior to oral standard of care for HIV prevention in women.

ViiV Healthcare, announced that an independent data safety monitoring board (DSMB) recommended the early unblinding of the HIV Prevention Trials Network (HPTN) 084 study evaluating the safety and efficacy of investigational, long-acting, injectable cabotegravir for HIV prevention in women. Following a pre-specified interim analysis, the DSMB indicated that cabotegravir met the primary objective of demonstrating superiority when compared to the current standard of care for women, daily oral emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg (FTC/TDF) tablets. The study showed cabotegravir was 89% more effective than daily oral FTC/TDF for pre-exposure prophylaxis (PrEP) . The early study unblinding for superior efficacy in this prevention trial in women follows results reported earlier this year from a companion study (HPTN 083) that also established long-acting cabotegravir’s superiority to daily oral PrEP in preventing HIV among men who have sex with men and transgender women who have sex with men. The HPTN 084 study , with 3,223 participants in 20 sites across seven countries in sub-Saharan Africa (Botswana, Kenya, Malawi, South Africa, eSwatini, Uganda and Zimbabwe), is the first study of long-acting injectable therapy for HIV prevention among women. The data showed that there was a statistically significant advantage for the women who received cabotegravir compared with the women who received FTC/TDF. While both were highly effective at preventing HIV in the study population, cabotegravir was superior. Among the 38 women in the trial who acquired HIV, four were randomised to the long-acting cabotegravir arm and 34 were randomised to the daily, oral FTC/TDF arm. This translated to an HIV incidence rate of 0.21% (95% confidence interval [CI] 0.06% – 0.54%) in the cabotegravir group and 1.79% (95% CI 1.24%-2.51%) in the FTC/TDF group. While both methods were highly effective at preventing HIV acquisition, long-acting cabotegravir was 89% (95% CI 68-96%) more effective than FTC/TDF. Preliminary assessment of adherence to oral FTC/TDF was higher than has been seen in prior HIV prevention studies in similar populations of women, based on a random subset of 362 FTC/TDF participants that measured any detectable tenofovir ( greater than 0.31 ng/ml) in 64% of participants with daily dosing levels (>40 ng/ml) in 48% of all samples tested. Long-acting cabotegravir and FTC/TDF tablets were both well tolerated throughout the study, with most adverse events being mild or moderate in severity and with the frequency largely balanced between both treatment arms. Injection site reactions (ISRs) were low in both groups and represented numerical improvements from what was demonstrated in the HPTN 083 study in men. ISRs in HPTN 084 occurred more frequently in the cabotegravir arm (32%) vs. the FTC/TDF arm (9%), which received placebo injections. There were no discontinuations due to injection site reactions or injection intolerance in either arm of the study. Gastrointestinal disorders and nausea were more common in the FTC/TDF arm.