Breakthrough in Preventing HIV Infection: Injectable PrEP

LOS ANGELES—While studio productions of adult movies have vanished during the state-ordered lockdowns of non-essential businesses, there may be good news for adult performers (and all sexually active people) when porn shooting returns. ViiV Healthcare, a global company established in November 2009 by GlaxoSmithKline and Pfizer that specializes in creating HIV treatment and prevention drugs, has announced that after a three-year study, the company's long-acting, injectable HIV prevention (PrEP) medication cabotegravir (CAB LA) is 69% percent more effective than daily pills in preventing HIV. In fact, the study is considered so successful that ViiV announced this past Sunday that it would end the 153-week-old study early, known as HPTN 083, and would offer the drug to all those who had been involved in the study and were taking oral PrEP medication.

"The HPTN 083 study, with approximately 4,600 participants across more than 40 sites in North and South America, Asia, and Africa, is one of the first-ever clinical trials to directly compare two active prevention agents," the company stated in a press release on May 18, noting that both cis males and transgender women were studied. "In a planned interim review, the independent Data and Safety Monitoring Board (DSMB) found the study data clearly indicated that long-acting injectable cabotegravir was highly effective at preventing HIV in the study population. Among the 50 people in the trial who acquired HIV, 12 were randomized to the long-acting cabotegravir arm and 38 were randomized to the daily, oral FTC/TDF [PrEP] arm. ... Adherence to oral [PrEP] was high, based on a random subset sampling that detected [oral PrEP tablet] tenofovir (> 0.31 ng/ml) in 87 percent of all samples tested. Despite this high level of adherence to oral therapy, long-acting cabotegravir was 69 percent more effective than [oral PrEP] in preventing HIV acquisition in the study population."

While other companies and agencies will continue to study the new injectable, at least one of the researchers involved in the ViiV study was hopeful that cabotegravir would be shown to be a breakthrough.

"Each year, an estimated 1.7 million people are newly diagnosed with HIV," noted Dr. Myron S. Cohen, Yeargan-Bate Distinguished Professor of Medicine, Microbiology and Immunology and Epidemiology at the University of North Carolina (UNC) at Chapel Hill, and co-principal investigator of the drug. "To lower that number, we believe more prevention options are needed in addition to currently available oral tablets for daily use. If approved, a new injectable agent, such as long-acting cabotegravir administered every two months, could play an important role in reducing HIV transmission and helping to end the HIV epidemic."

One of the failings of taking PrEP medication orally has been that users sometimes forget to take it regularly, leading to lower-than-effective levels of the chemical in their bloodstreams. Cabotegravir, with its once-every-two-month regimen, is expected to sidestep that problem, since appointments to receive the injections can be scheduled in advance so users' irregular self-dosages are no longer a problem.

"We commend ViiV Healthcare for its tremendous breakthrough with cabotegravir and thank the company for suspending its study to make CAB LA readily available to all study participants," said Michael Wohlfeiler, MD, JD, Chief of Medicine, US for AIDS Healthcare Foundation (AHF). "As an injectable, two-month dosed medication that’s demonstrated significantly greater efficacy than the current form of pre-exposure prophylaxis, cabotegravir offers an exciting way forward to far simpler and more effective HIV prevention."

Notably, AHF previously downplayed the use of PrEP as a "party drug," but the company has changed its tune, now that PrEP has proved effective in preventing HIV infections.

"From the very beginning of this debate, AHF voiced significant concerns about PrEP’s reliance on patient adherence to a daily pill regimen to achieve its preventive benefit," said Michael Weinstein, president of AHF, in a press release today. "ViiV’s remarkable study results here validate many of our earlier criticisms and concerns about PrEP. Cabotegravir looks to be an exciting new addition to the world of HIV prevention."

It is unclear just when cabotegravir will be available in the U.S.