Switch to Dolutegravir plus Rilpivirine Dual Therapy in cART-Experienced Subjects: An Observational Cohort

INTRODUCTION: Little information is available on the efficacy and safety of the dual combination of ripivirine plus dolutegravir. This work aims at beginning to fill this gap. METHODS: All HIV-1 infected subjects treated with ripivirine plus dolutegravir between October 2014 and September 2015 in eight Italian centres were included in an observational cohort. Data were collected at baseline and at weeks 4, 12, 24 and 48. RESULTS: One hundred and thirty-two subjects were followed for a median of 24 months, mean 33 months. One subject discontinued the study drug at week 24 for headache, one for drug interaction and one died after week 24 of illicit drug abuse. The mean age was 51.8, females 31.7% and non-caucasians 10%. Fifty-seven (43.2%) had at least one failure in their treatment history. Reasons for switching were simplification (53.0%), toxicity (34.8%), drug interactions (n = 7), persistent low-level viremia (n = 4), non-adherence (n = 3) and viral failure (n = 2). Sixty patients (45.5%) had reverse transcriptase (RT) mutations and 69 (44,7%) had protease (PR) mutations. Sixteen had baseline viral replication, 27 had < 50 HIV-1 RNA copies/mL and in 89 (67.4%) no virus was detected (NVD, 0 copies/mL). At w4, 114 (86.4%) had NVD, 15 had 1 to 49 HIV-1 RNA copies/mL and 3 had 50 to 57 copies/mL. At week 24 one subject had viral rebound without mutations due to missed drug refill, 19 had 1 to 49 copies/mL, and 112 had NVD. All 132 subjects were tested at weeks 4 and 24. Of the 50 subjects who had a 48-week follow-up, one had a treatment interruption, four had 1 to 49 copies/mL and 45 had NVD. Among the entire population, one subject had low-level, one intermediate and 4 high-level resistance to rilpivirine: none failed by week 48. Mean serum creatinine increased by +0.1 mg/dL. During the follow-up one patient reported headache and insomnia. CONCLUSIONS: Ripivirine plus dolutegravir proved safe and effective in this cohort of non-naïve HIV-1 infected subjects.