Patients on failing HIV regimens achieve viral suppression w
Researchers at the International AIDS Society Conference on HIV Science reported more promising data on lenacapavir, the investigational, long-acting HIV-1 capsid inhibitor that is administered subcutaneously every 6 months.

Data from an ongoing phase 2/3 study of heavily treatment-experienced people with multidrug-resistant HIV showed that 81% of participants who received lenacapavir in combination with an optimized background regimen achieved sustained virologic suppression at week 26.

“Lenacapavir emerges as a new and potent antiretroviral for the treatment of patients with multidrug-resistant viruses,” researchers told. “Its long half-life allowing one subcutaneous injection every 6 months will also improve adherence in these difficult-to-treat patients.”

Researchers randomly assigned 36 participants in a 2:1 ratio to add either oral lenacapavir or placebo to their failing regimen for 14 days. They received 600 mg on days 1 and 2, and 300 mg on day 8.

On day 15, participants in the lenacapavir arm received a 927 mg subcutaneous injection of lenacapavir. Participants in the placebo arm started the oral lead-in, followed by 927 mg subcutaneous lenacapavir. All participants began an optimized background regimen on day 15 as well.

In a separate nonrandomized cohort, 36 participants began an optimized background regimen concurrent with lenacapavir. The authors reported the efficacy at week 26 of the randomized cohort, as well as safety and efficacy information from both cohorts.

Overall, 25% of participants were female, 38% were Black and the median age of participants was 52 years. Median CD4 count was 150 cells/µL among participants. Mean HIV-1 RNA was 4.17 log c/mL, and the rate of resistance to two or more antiretrovirals in each class was 99% for nucleoside reverse transcriptase inhibitors, 97% for non-nucleoside reverse transcriptase inhibitors, 81% for protease inhibitors and 69% for integrase strand transfer inhibitors.

At week 26, 81% (29 of 36) of participants in the randomized cohort had a viral load of less than 50 c/mL, according to the researchers. Among participants with data from both cohorts, through week 26, 79% (33 of 42) had a viral load of less than 50 c/mL and the median CD4 count increased by 82 cells/µL.

Four participants in the randomized cohort experienced emergent lenacapavir resistance. Three suppressed afterward, one with a changed optimized background regimen and two without, researchers reported.

No serious adverse reactions or adverse reactions leading to discontinuations were reported. Lenacapavir-related injection site reactions occurred in 56% of participants (40 of 72) and were mostly mild or moderate (38 of 40). Common injection site reactions were swelling (26%) and erythema (24%).