NRTI-sparing regimen in clinical practice: the SCOLTA cohort

Background: HIV guidelines do not support the indication to offer a nucleoside-sparing (NUCs) regimen, especially in experienced patients. However, in the clinical setting NUCs regimens are quite common. The aim of this study was to evaluate the use of NUCS sparing regimens in a cohort of treatment-experienced patients. Methods: The Surveillance Cohort Long-Term Toxicity Antiretrovirals (SCOLTA) Project is a prospective, observational, multicenter study created to assess the incidence of adverse events in patients receiving new antiretroviral drugs raltegravir (RAL) and darunavir (DRV), enrolment is still ongoing. Results: Out of 668 patients enrolled in the RAL or DRV cohort, a total of 202 (30.2%) patients were prescribed NUCS sparing regimens. They were based on RAL (57 patients, 28.2%), DRV (14, 6.9%) or DRV/RAL (131, 64.8%). Patients' baseline characteristics were: 69.0% males, 92.2% Caucasian, 38.3% stage C, 38.9% lipodistrophy, 37.3% HCV coinfected. At the enrolment, the median age was 46 years (20-78), and the median duration of HIV treatment was 12.4 years (range 0-21); median CD4+ were 361 cells/mmc (range 6-1318), median HIV-RNA 3.3 log10 (range 0.9-6.1). Only 3 patients were naïve at enrolment date. From 2005 to 2010 we identified an increase of NUCs sparing schemes (5.9% to 30.6%) (p=0.001). DRV/ritonavir plus RAL is the most prescribed regimen (33,1%). Comparison between patients on NUCS regimens and patients treated with backbone showed a significant difference in the proportion of HCV-coinfection: 36.6% and 26.2% respectively (p=0.005). Conclusion: This analysis provides an important information about the frequency of regimens NUCs sparing use in the clinical practice. In our cohort RAL and DRV were often used without the backbone. Patients with co-infection with hepatitis C therapy were administered NUCs sparing regime more frequently than HCV-negative subjects, presumably to limit the toxicity.