A new HIV prevention pill that offers protection for up to a month with a single dose is advancing to phase three clinical trials after promising early results. The drug, currently called MK-8527, is a long-acting nucleoside reverse transcriptase translocation inhibitor (NRTTI), designed to block a crucial step in the virus replication process.
Phase two trials, conducted in South Africa, the US, and Israel, tested three different dosages 3mg, 6mg, and 12mg over six months. Participants received a single pill monthly and were monitored for at least two months afterward. None of the 350 participants contracted HIV during the trial. The drug was well-tolerated, with a safety profile comparable to placebo, and showed no toxic drug accumulation in the body over time.
Increased attention was given to immune system indicators, including CD4 and lymphocyte counts, due to the drug’s similarity in action to Islatravir, a compound previously linked to declines in those values. No significant changes were observed, reinforcing the drug’s safety. The most common side effects were mild headache, fatigue, and nausea and occurred at similar rates in both the drug and placebo groups.
Importantly, the 6mg and 12mg doses maintained protective drug levels for over 28 days, with a potential one-week grace period for late dosing. The drug also appears to act quickly, potentially offering protection within an hour of ingestion.
Two large-scale phase three trials, EXPrESSIVE-10 and EXPrESSIVE-11, are now being launched across 16 countries, including South Africa, Kenya, Uganda, and the United States. These studies aim to enroll over 9,000 participants and will compare the monthly pill to the currently available daily oral PrEP.
The new option could be particularly valuable for individuals who find daily pills or injections inconvenient. A monthly pill could bridge gaps in adherence and expand prevention options. Experts believe it could also be more cost-effective than injectable alternatives, increasing accessibility, especially in low-resource settings.
As the studies continue, optimism remains high that MK-8527 could significantly strengthen the HIV prevention toolkit, offering a discreet, user-friendly, and affordable alternative that meets the diverse needs of global populations.
