A combination of two drugs could replace the daily intake of an HIV treatment with a single pill each week. This therapy is being studied in adults whose viral load is already undetectable. It therefore does not yet concern people who are starting their treatment.
HIV remains present in the body, even when medications prevent the virus from multiplying and make it undetectable in the blood. Treatment must then be continued regularly. A weekly intake could simplify daily life without changing the main goal: keeping the virus under control.
The pill combines islatravir, developed by Merck, and lenacapavir, developed by Gilead Sciences. These two molecules act in different ways, but their intended effect is similar: preventing HIV from producing new copies of itself. This combination thus targets several steps of the virus's replication cycle.
The announced results come from two Phase 3 clinical trials, called ISLEND-1 and ISLEND-2. This stage corresponds to studies conducted on a large number of participants, in order to compare the new treatment to already used therapies. Here, the weekly intake was compared to daily antiretroviral treatments.
After 48 weeks, the combination kept the virus under control in the participants concerned. The results were comparable to those of the daily treatments used as a reference in both trials. In other words, the reduced dosing frequency did not lead to a loss of efficacy under the studied conditions.
For people living with HIV, the benefit would be mainly practical. A single pill to take each week could replace a sometimes burdensome daily routine. This arrangement would not eliminate the treatment, but it could make its management simpler and reduce the space it takes up in everyday life.
A less frequent intake could also help some people avoid missing doses. However, the benefit would not be the same for everyone, because habits, health status, and needs vary from patient to patient. Medical follow-up would therefore remain necessary to verify the effectiveness and tolerability of the treatment.
The safety profile observed was generally comparable to that of the reference treatments. The companies indicate that no new concerning signal has been identified in these initial results. However, these data will need to be examined in detail, because clinical trials do not always allow predicting all the effects that would appear with longer-term use.
The combination remains experimental and is not yet approved. Health authorities will need to analyze all the results before deciding whether it can be offered to patients. If approved, it could become the first complete oral HIV treatment taken once a week, but this possibility still depends on this evaluation.