Subcutaneous formulation of long-acting CAB/RPV discontinued

A new subcutaneous (SC) formulation of long-acting cabotegravir and rilpivirine (CAB-LA/RPV-LA) unfortunately turned out to have poorer tolerability compared to the current intramuscular (IM) gluteal injections.

Results were presented from a substudy in 93 participants in the phase 3 FLAIR study who were given three SC abdominal injections before returning to IM.

Although plasma drug levels of cabotegravir and rilpivirine were generally comparable for both formulations, injection site reactions were more difficult to tolerate. This included nodules persisting for a median of 39 days compared to 9 days with IM.

Although there were no virologic failures, five participants discontinued the substudy due to injection site reactions.

Patient questionnaires reported significantly lower treatment acceptability and satisfaction with the SC formulation, although about one-third preferred the convenience of SC injections.

These results led to ViiV discontinuing this SC formulation although the presenter emphasised that ViiV remains committed to further research that would enable self-administration.

D’Amico R et al, Subcutaneous injections of cabotegravir + rilpivirine in virally suppressed adults with HIV-1: a substudy of the Phase 3 FLAIR study. AIDS 2024, 22–26 July 2024, Munich. Oral abstract OAB2604.
https://programme.aids2024.org/Abstract/Abstract/?abstractid=1785