Long-Term Effectiveness of Rilpivirine-Based Single-Tablet Regimens in a Seven-Year, Two-Center Observational Cohort of People Living with HIV

Data on the long-term durability of rilpivirine (RPV) are still scarce. A two-center retrospective study was performed, including all people living with HIV (PLWH) treated with tenofovir disoproxil fumarate/emtricitabine (TDF/FTC)/RPV or tenofovir alafenamide (TAF)/FTC/RPV in the period January 2013-December 2019. Aims of the study were to assess the rate of discontinuation of the RPV single-tablet regimen (STR) and identify factors associated with the risk of discontinuation according to Cox's regression analysis. A total of 684 PLWH were enrolled. Mean duration of RPV-STR treatment was 192.5 (+/- 99.5) weeks for 123 antiretroviral therapy (ART)-naive participants (18%) and 173.3 (+/- 85.6) weeks for 561 ART-experienced study participants (82%). During the study period, the incidence of discontinuation was 7.7 per 100 person-years. The estimated proportions of discontinuation after 48 and 96 weeks were 5.6% and 13.4%, respectively. Causes of discontinuation were loss to follow-up (30%), side effects (15%), ART optimization (14%), virological failure (VF) (12%), death or transfer to another center (9%), low adherence (7%), drug interactions (6%), simplification to dual therapy (3%), and unknown (3%). No differences were observed in cumulative probability of discontinuation between ART-naive and -experienced PLWH. Heterosexual (hazard ratio [HR] 3.0, 95% confidence interval [CI] 1.4-6.8) and mother-to-child (HR 5.3, 95% CI 1.8-15.3) transmission of HIV infection and history of previous VF (HR 1.7, 95% CI 1.2-2.5) were associated with higher risk of discontinuation. High RPV-STR effectiveness and durability were confirmed in our real-life population of PLWH. Given these data, RPV has the potential to be a drug for life in patients selected according to current guidelines.