Study: Investigational PrEP Drug More Effective Than Daily Pills in Preventing HIV-1

Data from the HPTN 083 study has found that cabotegravir, an investigational, long-acting, injectable drug administered every 2 months, is 66% more effective than daily pre-exposure prophylaxis (PrEP) pills at preventing HIV-1 infection.

The study is a Phase IIb/III randomized, multicenter, double-blind, clinical trial that is evaluating the use of cabotegravir among men who have sex with men (MSM) and transgender women who have sex with men. In results announced at the virtual 23^rd International AIDS Conference, investigators found that cabotegravir is 66% more effective than daily oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) 200 mg and 300 mg tablets.

“This advancement has the potential to be a game-changer for HIV prevention, offering an option with very high rates of effectiveness and the convenience of reduced dosing from daily to just 6 times per year,” said Kimberly Smith, MD, MPH, head of research and development at ViiV Healthcare, in a statement.

The study enrolled HIV-negative men and transgender women who have sex with men, 2 populations at increased risk for acquiring HIV. According to a press release, two-thirds of the participants were under age 30 years, and 12% were transgender women. Half of the participants in the United States identified as Black or African American.

The final analysis found 52 cases of HIV, with 13 occurring in the long-acting cabotegravir arm and 39 occurring in the daily, oral FTC/TDF arm. According to a press release, this means an HIV incidence rate of 0.41% in the cabotegravir group compared with 1.22% in the FTC/TDF group. Preliminary assessment of adherence rates found a high adherence in the FTC/TDF arm.

Both treatments were well tolerated throughout the study, with mostly mild or moderate adverse events. Injection site reactions, pyrexia, and hypertension were more common in patients who received cabotegravir, while nausea was more common in the FTC/TDF arm.

“Medicines that help prevent new HIV incidence are essential to our ongoing global fight to end the HIV epidemic,” said Myron S. Cohen, co-principal investigator, in a statement. “It’s exciting to discover that with injectable, long-acting cabotegravir, we now have compelling clinical evidence of another effective PrEP option that could play a critical role in helping to reduce HIV transmission that will ultimately save lives.”

REFERENCE

ViiV Healthcare announces superior efficacy of investigational, long-acting injectable formulation of cabotegravir dosed every two months over daily oral PrEP [news release]. ViiV Healthcare; July 7, 2020. https://viivhealthcare.com/en-us/us-news/us-articles/2020/viiv-healthcare-announces-superior-efficacy-of-investigational--/. Accessed July 8, 2020.