Treatment outcome for NRTI-sparing regimen consisting of dolutegravir and rilpivirine in HIV-1 infected patients

Objectives The nucleoside reverse transcriptase inhibitors (NRTI) have been an important 'back-bone' of an antiretroviral therapy (ART) for HIV-1 infected patients. However, these agents have been associated with both short and long-term toxicity. Therefore, there has been growing interest in evaluating NRTI-sparing regimens. Now we have administered dolutegravir (DTG) and rilpivirine (RPV) to HIV-1 infected patients as a new NRTI-sparing regimen. However, there are few data on the outcome of ART regimen consisting of DTG and RPV. In this study, we examined treatment outcome for this NRTI-sparing regimen in HIV-1 infected patients. Method We examined 27 HIV-1 infected patients treated with NRTI-sparing regimen consisting of DTG and RPV in Nagoya Medical Center, Japan. We checked efficacy and safety for this regimen from 2014 to 2015, retrospectively. Results Median duration of this NRTI-sparing regimen for 27 Japanese HIV-1 infected patients (26 males, 1 female; mean age 57 years) was 323 days. The reasons for changing to this regimen were pill burden (n=13), lipodystrophy related to NRTI (n=7), myelopathy (n=2), renal dysfunction (n=1), dyslipidemia (n=1), respectively. Finally, 25 patients have continued this regimen. After starting this regimen, HIV viral load were soon less than the detection limit for all patients. Virologic failure and regimen discontinuations by severe adverse reactions were not confirmed for individuals. In addition, abnormal laboratory data (ALT, AST, etc) were not shown for all patients. Conclusions Current UK and US treatment guidelines do not recommend NRTI-sparing regimens for people starting ART due to concerns about toxicity, treatment discontinuation, and drug resistance. In this study, 12 patients had been already treated with NRTI-sparing regimen (Raltegravir + RPV). As these patients were elder, it was essential to reduce pill burden. Therefore, a new NRTI-sparing regimen, DTG + RPV, will be available in the future because of reducing pill burden, few drug interactions and low toxicity.