Antiretroviral Therapy Prescribing Practices and Virologic Response in HIV-Infected Individuals with the M184V Mutation: Results from the 550 Clinic Cohort Study

BACKGROUND: Human immunodeficiency virus (HIV) treatment guidelines recommend using a regimen that contains three fully active antiretroviral agents in patients with drug resistance mutations. However, some evidence suggests that protease inhibitor (PI) based regimens containing less than three fully active drugs may be as efficacious in achieving viral suppression (VS) as a three-drug regimen in the presence of a M184V mutation. The purpose of this study was to identify current prescribing practices and determine if VS can be achieved with regimens containing less than three fully active agents in patients with a M184V mutation. METHODS: A single-center retrospective chart review was conducted on patients receiving treatment at the 550 Clinic from January 2003 to July 2016. Patients were screened for a M184V mutation. Patients were excluded for lack of a genotype and inadequate documentation of viral load (VL) prior to initiating or changing therapy. Regimens were characterized as containing three fully active agents or less and evaluated for VS success (VL less than 200 copies/mL). Data was analyzed using descriptive statistics, Chi-square tests, and Fischer’s exact tests. RESULTS: A M184V mutation was identified in 100 of the 754 patients screened for inclusion. 90% of the 167 regimens evaluated contained less than three fully active drugs. PI-based regimens (n = 86) and integrase strand transfer inhibitor (INSTI)-based regimens (n = 25) were the most commonly prescribed regimens containing less than three fully active drugs. VS was achieved with 72% of regimens containing less than three fully active agents compared with 69% of those containing three fully active agents (P = 0.108). In patients with a baseline VL greater than 100,000 copies/mL, VS was achieved with 80% of INSTI-based regimens compared with 21% of PI-based regimens (P = 0.040). VS was achieved with 85% of INSTI-based regimens and 78% of PI-based regimens in those with a baseline VL less than 100,000 copies/mL (P = 0.513). CONCLUSION: Regimens containing less than three fully active drugs may be as efficacious as regimens containing three fully active drugs in those with a M184V mutation. In those with a high baseline VL, INSTI-based regimens may have better efficacy compared with PI-based regimens. DISCLOSURES: All authors: No reported disclosures.