Stribild safer, more effective than combination treatment in women with HIV
SAN DIEGO — An ART regimen consisting of once-daily Stribild may be safer and more effective in women with HIV-1 infection than a standard multidrug combination treatment, according to a study presented here at ICAAC 2015.
This is the first fully powered ART efficacy study to exclusively enroll women, and its results contrasted with those of a previous study of the drug which enrolled mostly men, according to Sally Hodder, MD, director of the West Virginia Clinical and Translational Science Institute.
“Historically, we’ve accepted 10% women in clinical trials,” Hodder said during a press event. “Regulatory agencies have made decisions based on very small populations of women, but obviously their approval is for the whole population. It’s really important to have this trial … I think it’s really a milestone because it was enrolling all women.”
In the international, randomized, double blind WAVES study, Hodder and colleagues evaluated the safety and efficacy of a single tablet of Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate, Gilead Sciences; EVG/COBI/FTC/TDF) among a cohort of women with HIV and no history of ART. A total of 575 participants from Africa, Asia, Europe, Latin America and North America were enrolled in the study, half of whom were randomly assigned daily EVG/COBI/FTC/TDF and half assigned a combination treatment comprising Norvir (ritonavir, AbbVie; RTV)-boosted Reyataz (atazanavir, Bristol-Myers Squibb; ATV) plus FTC/TDF (RTV+ATV+FTC/TDF). Efficacy was determined by the proportion of participants who achieved HIV-1 RNA fewer than 50 cells/mL at week 48, and subgroup analyses were performed by region.
Baseline characteristics were comparable across all regions. The median age of participants was 35 years; approximately half were black (48%). Most reported unprotected heterosexual intercourse as the source of their infection.
At week 48, EVG/COBI/FTC/TDF was associated with an 87.2% rate of viral suppression, as opposed to an 80.8% rate among those given RTV+ATV+FTC/TDF (adjusted difference = 6.5%; 95% CI, 0.4%-12.6%). Virologic response to both regimens was greatest in Uganda and lowest in the U.S., and according to Hodder, it was well correlated to adherence in these regions.
Virologic failure associated with the development of resistance was not seen among participants given EVG/COBI/FTC/TDF, although there were three such cases reported in the RTV+ATV+FTC/TDF arm. In addition, discontinuations due to adverse events were more frequent among those given RTV+ATV+FTC/TDF (19 vs. 5).
According to Hodder, results that prove the efficacy of a single-tablet treatment are especially important in light of the stigma facing many women with HIV.
“Despite the fact that we are more than 30 years into the HIV epidemic … in many communities in which women live they are not supported, and in fact I had women who really did not want anyone to know they were taking HIV medicine,” Hodder said. “The simple one tablet, once a day has made it much easier for patients to be able to handle.”
Hodder S, et al. Elvitegravir (EVG)/Cobicistat(COBI)/Emtricitabine(FTC)/Tenofovir Disoproxil Fumarate(TDF) is Superior to Ritonavir (RTV) Boosted Atazanavir (ATV) Plus FTC/TDF in Treatment Naïve Women with HIV-1 Infection (WAVES Study). Presented at: Interscience Conference on Antimicrobial Agents and Chemotherapy; Sept. 17-21, 2015; San Diego.
Disclosure: The study, in which Hodder was an investigator, was supported by Gilead Sciences. Please see the full study for a list of all other authors’ relevant disclosures.