‘Reassuring’: No interaction between long-acting HIV drug, contraceptives
Click Here to Manage Email Alerts
Key takeaways:
- HIV PrEP agents, including long-acting cabotegravir, had no effect on hormonal contraceptives.
- ViiV Healthcare will increase the doses of cabotegravir available to lower income countries.
LIMA, Peru — In a finding described as “reassuring,” researchers detected no interaction between the long-acting HIV prevention drug cabotegravir and hormonal contraceptives among women enrolled in a large trial.
The results were from a substudy of the HIV Prevention Trials Network 084 study (HPTN 084), which was conducted in seven sub-Saharan countries. In 2021, results from the trial showed that cabotegravir — which is administered by injection every 2 months — reduced HIV infections among cisgender women by around nine times compared with daily oral PrEP.
Additional HPTN 084 results presented at a conference last year showed that cisgender women preferred cabotegravir to daily oral PrEP by a margin of nearly 4 to 1.
In the substudy, Mark A. Marzinke, PhD, professor of pathology and medicine at the Johns Hopkins University School of Medicine, and colleagues assessed whether there were pharmacologic interactions between cabotegravir or the daily oral PrEP medication emtricitabine/tenofovir disoproxil fumarate and three hormonal contraceptive agents commonly used in eastern and southern Africa: etonogestrel implants, medroxyprogesterone acetate and injectable norethindrone.
Specifically, they looked to see if the PrEP agents affected the levels of contraceptive concentrations associated with preventing pregnancy, or whether the contraceptives affected the PrEP medications, Marzinke told reporters during a press conference at the HIV Research for Prevention meeting.
The researchers enrolled 170 participants in the substudy from Feb. 24 to Oct. 26, 2020, and randomly assigned 90 of them to the oral PrEP arm and 80 to receive cabotegravir. They measured each participant’s contraceptive and PrEP drug concentrations at enrollment, then at weeks 25, 49 and 73.
Testing showed that the proportion of participants with contraceptive concentrations sufficient to prevent pregnancy remained high in both groups (P = 0.423-1).
Levels of cabotegravir were similar regardless of which contraceptive method women used, but the researchers could not assess oral PrEP concentrations in the same way because adherence in that study arm was low — 36% did not have measurable levels of tenofovir in their system, Marzinke said.
“Based on our analysis, we can conclude and confirm that there were no relationships between cabotegravir and the hormonal contraceptive agents,” he said. “But additional associations between [oral PrEP] and those contraceptive agents could not be determined due to low adherence.”
Results of the study were reported on the same day that ViiV Healthcare announced it would triple the supply of cabotegravir that will be available for low- and middle-income countries in 2025 and 2026 to at least 2 million doses.
International AIDS Society President Beatriz Grinsztejn, MD, PhD, was encouraged by the new findings.
“These are very important and reassuring results as we move forward with long-acting cabotegravir scale-up,” said Grinsztejn, director of the HIV/AIDS clinical research unit at the Evandro Chagas National Institute of Infectious Diseases in Rio de Janeiro, who was not involved in the research.
[Editor’s note: Gallagher’s attendance at the conference was partially funded by a journalism fellowship awarded by the International AIDS Society.]
Reference:
- Marzinke MA, et al. Abstract PRC140. Presented at: HIV Research for Prevention; Oct. 6-10; Lima, Peru.
- ViiV Healthcare to triple annual supply of long-acting HIV PrEP for low- and middle-income countries. https://viivhealthcare.com/hiv-news-and-media/news/press-releases/2024/october/triple-annual-supply-of-long-acting-hiv-prep-for-low-and-middle-income-countries/. Published Oct. 7, 2024. Accessed Oct. 9, 2024.
Collapse
Press Conference
Read more about
Click Here to Manage Email Alerts