New HIV preventative 69% more effective than current treatments

In a significant development, the HIV Prevention Trials Network (HPTN) on Monday announced that global trials had shown that long-acting injectable cabotegravir (CAB LA) given once every two months lowered HIV incidence among cisgender men and transgender women who have sex with men.

ViiV Healthcare, GlaxoSmithKline’s global specialist HIV company, announced that interim analysis of the study revealed that cabotegravir was found to be 69 % more effective in preventing HIV when compared to the current standard care regimen of daily PrEP pills of emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg.

Glaxo said that the study will be presented at an upcoming scientific meeting. It is important to note that cabotegravir as a single agent has not yet been approved for the treatment or prevention of HIV.

“Demonstrating conclusively that long-acting injectable cabotegravir is highly effective almost two years earlier than originally expected is exciting news,” said Dr Raphael J. Landovitz,  protocol chair of the study.

“It is inspiring that we may soon have additional HIV prevention options for at-risk individuals who have difficulty with or prefer not to take pills, ” said Landovitz, a professor of medicine in the Division of Infectious Diseases at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA) and associate director of the UCLA Center for Clinical AIDS Research & Education (CARE).

“These study results demonstrate that long-acting injectable cabotegravir dosed every two months can successfully reduce HIV acquisition in at-risk MSM (men who have sex with men)  and transgender women,” said Dr Kimberly Smith, Head of Research & Development at ViiV Healthcare.

“We are thrilled with the results not only because of the high efficacy of cabotegravir but also because we have demonstrated high efficacy in a study that adequately represents some of the populations most disproportionately impacted by HIV — black MSM in the US, young MSM globally and transgender women,” said Smith.

A companion study on the effectiveness of cabotegravir in women is yet to be completed.

“If approved, this long-acting injectable has the potential to be a game-changer for HIV prevention by reducing the frequency of dosing from 365 days to six times per year,” added Smith.

The HPTN study was carried out in 4,570 cisgender men and transgender women who have sex with men in the United States, Argentina, Brazil, Peru, Thailand, Vietnam, and South Africa. Around two thirds of the participants were under 30 years of age, 12 % were transgender women and halF of the participants in the US identified as Black or African-American.

During the trial, 50 people acquired HIV, 12 from the randomised cabotegravir group and 38 in the oral FTC/TDF group. “Despite the high level of adherence to oral therapy, long-acting cabotegravir was 69% more effective than FTC/TDF in preventing HIV acquisition in the study population,” Glaxo said.

Dr Beatriz Grinsztejn, protocol co-chair said that a long-acting injection for PrEP was a “great addition to the HIV prevention toolbox. Prevention strategies have never been one-size-fits-all.”

The independent Data and Safety Monitoring Board (DSMB) recommended the study’s end and that the interim results should be announced. The HPTN study was jointly funded by  the National Institute of Allergy and Infectious Diseases (NIAID) and ViiV Healthcare.