557. Evaluation of Clinical Response of a Two Tablet Once Daily Antiretroviral Regimen in Antiretroviral Experienced HIV-Infected Patients

BACKGROUND: The benefits of antiretroviral therapy (ART) are compromised by virologic failure and drug resistance. To maintain virologic suppression, these patients have traditionally required multitablet “salvage” regimens. We retrospectively analyzed data to assess virologic efficacy of a two-tablet, once daily combination of Elvitegravir/Cobicistat/Emtricitabine/TAF plus Darunavir (G/D) in HIV-infected adults with history of prior resistance and regimen failure. METHODS: Electronic Medical Records of HIV-infected adults with history of prior resistance and regimen failure in our HIV-Clinic were analyzed to assess efficacy of a two-tablet ART regimen of G/D. Efficacy was defined as percentage of participants with HIV-1 RNA <50 copies/mL. Statistical analysis included descriptive summary of all patients. Categorical variables (gender, mode of transmission, the presence of undetected viral load, the presence of viral load <50, class resistance number, and the presence of M184V mutation) were compared between the two outcome groups (success vs. failure) using the Fisher exact test. The two groups were also compared using Student’s two-sample t-test for normally distributed numerical variables (age and number of years from diagnosis to regimen change) and the Wilcoxon rank-sum test for non-normally distributed numerical variables (CD4 level at diagnosis and CD4 level at regimen change). RESULTS: Thirty-four patients were included in the study, of which 70.6% were men, majority MSM: 64.7%. Patients had been diagnosed with HIV for a median of 13.8 ± 7.3 years. More than 50% of patients at time of switch were on four pills and 53% were on a BID regimen. 61.7% patients were virologically suppressed with the regimen of G/D. There was no difference between virologic success vs. failure group when following variables were compared: CD4 at the time of regimen change, undetectable HIV VL vs. viremic patients at regimen change, the number of drug class resistance, the presence of M184 V mutation. Only statistically significant variable was age, virologic failure arm patients were younger; 35.8 vs. 48.2 years. CONCLUSION: Despite the small numbers of patients, our results demonstrate that in a clinical setting a two tablet regimen provides substantial efficacy in ART-experienced patients harboring resistant virus. DISCLOSURES: I. Brar, Gilead: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium. Janssen: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium. Viiv: Research Contractor, Research grant.