Once-Monthly PrEP May Become a Viable HIV Option

Phase 3 trials for islatravir are underway. What are investigators considering with the Merck investigative drug?

New trial data from Merck showed investigative once-monthly pre-exposure prophylaxis (PrEP) islatravir was associated with good tolerability and predominately mild adverse events versus placebo among patients at low-risk of HIV-1 infection, in 24-week, phase 2A trial data.

The findings, presented this week at the International AIDS Society (IAS) 2021 Conference on HIV Science, alluded to the therapeutic potential of a longer-duration PrEP option among a broad patient population.

But ongoing phase 3 trials may better inform its absolute potential among other available PrEP.

In the second segment of an interview with Contagion during IAS 2021, study author Sharon Hillier, PhD, director of Reproductive Infectious Disease Research at UPMC Magee-Womens Hospital in Pittsburgh, discussed the 2 ongoing phase 3 studies for islatravir, in which the agent is being observed for HIV incidence versus available once-daily, fixed-dose marketed PrEP, as well as in populations such as men who have sex with men and transgender women.

As Hillier explained, the trials will help inform investigators as to whether a once-monthly PrEP is as good, if not better, than once-daily combinations.

“And ‘better’ can be a number of things,” Hillier explained. “Better at blocking HIV, or more tolerable, or easier to adhere to.”

Hillier also shared perspective on the aging HIV-risk population, and how research can continue to assure therapeutic prophylaxes are tailored to their needs.