Rilpivirine use in the Swiss HIV cohort study: a prospective cohort study.

Background: Rilpivirine is safe and effective in HIV-naïve patients with low baseline HIV-RNA or in switch strategy. It offers the advantages of few drug-drug interactions and a favourable toxicity profile. We aimed to determine the reasons for prescribing the rilpivirine (RPV)/tenofovir disoproxil (TDF)/emtricitabine (FTC) co-formulation within the Swiss HIV Cohort Study and to assess its effectiveness and safety over a 24 months period.
Methods: All individuals enrolled in the Swiss HIV Cohort Study who initiated a RPV/TDF/FTC co-formulation between April 2013 and March 2014 were included. Primary outcomes were the HIV-RNA viral load (copies/mL) and CD4 cell count (cells/mm ³ ) at 6, 12 and 24 months. Reasons for a switch to RPV/TDF/FTC were evaluated through a standardized questionnaire. We also assessed discontinuation and reasons for discontinuation of RPV/TDF/FTC until October 30, 2015.
Results: Of 644 individuals who started the RPV/TDF/FTC co-formulation, only 7.5% were treatment-naïve. At 24 months, viral suppression (HIV-RNA <50 copies/mL) was achieved in 100% and 96.7% of cART-naïve and cART-experienced patients respectively. The switch to RPV was mainly done for simplification (44.6%) and to overcome central nervous system toxicity symptoms due to efavirenz (24%). Six months after switch, 74.8% of patients reported an improvement of psycho-neurological symptoms with continued improvement at 12 months for almost 80%. However, one quarter of patients reported a discontinuation of RPV/TDF/FTC on October 30, 2015 after a median time of 18.4 months. Reasons for discontinuation included physician decision (5.3%) and side-effects (3.9%) mainly related to the central nervous system and to renal toxicity.
Conclusion: The RPV/TDF/FTC co-formulation was safe and effective throughout 24 months of follow-up but barely prescribed for HIV-naïve patients. Despite excellent virological suppression among both treatment-naïve and -experienced patients, we observed a high rate of treatment discontinuation.