A French national observatory of people with HIV initiating lenacapavir-based treatment after regulatory approval.

There is limited data on lenacapavir (LEN) use, the newest capsid inhibitor, in observational settings. We describe population characteristics and pharmaco-virological outcomes of people with HIV-1 (PWH) who initiated LEN-based treatment. We conducted a national retrospective observational study of PWH initiating LEN-based treatment in France after its approval (December 2022). Virological failure (VF) was defined as two consecutive viral loads (VLs) ≥50 c/mL, and a non-virological response as a VL decrease of <1 log10 c/mL or still >50 c/mL at W24. Ninety-six PWH were included; 49 were virologically suppressed at initiation. Median follow-up on LEN was 12 months (IQR = 8-17). Genotypic susceptibility score was <1 in 59 cases (61%). Twelve participants (12.5%) discontinued LEN-based treatment. Among the virologically suppressed and viremic PWH at initiation, 94% and 64% had VL <50 c/mL at the last follow-up visit, respectively. VF occurred in 8 PWH (3 in virological success and 5 viremic at baseline), and a non-virological response was observed in 12 PWH. Capsid sequence at VF was available for eight subjects, showing the emergence of N74D mutation in one. LEN plasma concentrations were available for 13 of the 20 PWH presenting with VF or non-response with adequate concentrations in 90% of cases. Twenty-four participants received cabotegravir + LEN, 18 having VL <50 c/mL at the last follow-up visit. Our observational findings confirm that LEN-based regimens are effective among heavily treatment-experienced individuals with advanced resistance. In this population, LEN-based treatments were associated with high rates of sustained virological suppression and a low incidence of capsid emergent resistance.