ViiV Healthcare is conducting a phase III, randomized, multicenter, parallel-group, non-inferiority, open-label study evaluating the efficacy, safety, and tolerability of CAB ULA + RPV ULA or CAB LA + RPV LA in adults and adolescents with HIV who are virologically suppressed on antiretroviraltherapy (ART). As part of the trial, ViiV Healthcare/GSK also wants to investigate the implementation feasibility of the different treatment regimens. This research involves rigorous methods to assess the implementation context and facilitate the systematic integration of research findings into routine clinical practice.