Injectable cabotegravir effective as HIV PrEP when given every 2 months
Administered as an injection every 2 months, the investigational drug cabotegravir was 69% more effective at preventing HIV than currently approved pre-exposure prophylaxis, or PrEP, ViiV Healthcare said today.
The finding was part of an interim analysis of data from the HIV Prevention Trials Network (HPTN) 083 study. The data have not been peer reviewed, but ViiV said detailed results will be presented at an upcoming meeting. It plans to use the data for regulatory submissions.
HPTN 083 enrolled approximately 4,600 men who have sex with men and transgender women at more than 40 sites in the United States, Argentina, Brazil, Peru, South Africa, Thailand and Vietnam and randomly assigned them to receive an injection of cabotegravir every 8 weeks or daily oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF). Two-thirds of the study participants were aged younger than 30 years and 12% were transgender women, ViiV said. In the U.S., half of the participants identified as black or African American.
According to ViiV:
- Among 50 participants who acquired HIV, 12 were randomly assigned long-acting cabotegravir and 38 were randomly assigned to FTC/TD, for an HIV incidence rate of 0.38% (95% CI, 0.2%-0.66%) in the cabotegravir arm and 1.21% (95% CI, 0.86%-1.66%) in the FTC/TDF arm.
- Despite a high level of adherence to oral FTC/TDF — 87% of tested samples were positive for tenofovir — the study showed that long-acting cabotegravir was 69% (95% CI, 41%-84%) more effective than FTC/TDF in preventing HIV acquisition.
“This is a practice-changing study,” Carlos del Rio, MD, executive associate dean at Emory University School of Medicine, told Healio. Del Rio was a protocol team member and an investigator on the study.
After an independent data and safety monitoring board (DSMB) found that the study data “clearly indicated” cabotegravir was highly effective at preventing HIV, it recommended that the blinded, randomized portion of the phase 2b/3 study be terminated, ViiV said. The company said that participants in the FTC/TDF arm would be offered the chance to receive cabotegravir. Safety was similar in both groups.
Another trial, HPTN 084, is evaluating injectable cabotegravir as HIV PrEP among women who are at an increased risk for HIV. The trial, which started a year after HPTN 083, is being conducted in seven African countries. ViiV said the DSMB also reviewed data from that trial and recommended that it continue as planned.