Efficacy and safety of raltegravir in switch strategies in virologically suppressed patients: long-term data from clinical practice

Sir, We appreciated the recently published work by d’Arminio Monforte et al.1 on the durability of integrase strand transfer inhibitors (INSTIs) in a large cohort of treatment-naive HIV-positive patients. Indeed, INSTI-based regimens have become the first choice for initial HIV therapy, but they are also very popular as part of three-drug or two-drug switching strategies. Eleven years have passed since the first-generation INSTI, raltegravir, was introduced. Despite the availability of the new INSTIs, such as dolutegravir (with higher genetic barrier) and elvitegravir (available as a single tablet regimen), raltegravir still plays an important role in combination ART (cART).2 The major advantages of using raltegravir are the virtual absence of potential interactions with concomitant drugs and its high bioavailability irrespective of food intake. To investigate the safety and efficacy of raltegravir in the setting of cART optimization, we performed a retrospective study enrolling HIV-1-infected, virologically suppressed (defined as HIV-RNA <50 copies/mL) patients switching to a raltegravir-containing dual or triple therapy. The study period ranged from September 2008 to May 2017. We evaluated the percentage of patients free from treatment discontinuation (TD; discontinuation of raltegravir for any reason regardless of whether the remaining antiretroviral drugs used in the combination had been stopped or not) and from virological failure (VF; defined as two consecutive counts of HIV-RNA ≥50 copies/mL or one of ≥1000 copies/mL) at weeks 48, 96 and 144. Kaplan–Meier curves and Cox regression models were performed to estimate the time to event and the predictors of TD and VF. Data analysed in the present study were selected from an internal observational database, which collects the main clinical and demographic characteristics of every patient who gave informed consent to personal data record since the time of HIV diagnosis. The creation of the database was approved by the Fondazione Policlinico Gemelli Ethics Committee (protocol number: 10978/15).