Primary and secondary analyses of emergent drug resistance through week 96 from the Phase III studies of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate

• Published in: Antiviral therapy Vol. 18; p. A103
• Main Authors: White, K L, Kulkarni, R, Abram, M, Rhee, M, dyce, M, Miller, M D
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: Human immunodeficiency virus 1
• ISSN: 1359-6535

Phase III studies of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (Stribild [STB]) in treatment-naive subjects showed non-inferior efficacy to efavirenz/ emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/ TDF; Atripla [ATR]) or ritonavir-boosted atazanavir (ATV+RTV)+FTC/TDF for HIV-1 RNA[lessthan]50 copies/ml at weeks 48 and 96. This study presents analyses of the 16 STB subjects with emergent resistance, pre-existing IN mutation effect on outcome, and analyses of subjects who discontinued before week 8 or with HIV-1 RNA 50-399 copies/ml. The resistance analysis population (RAP) had genotypic/phenotypic analyses at failure confirmation and baseline for PR/RT/IN. The primary RAP studied subjects with HIV-1 RNA[greater than or equal]400 copies/ml at virological failure, discontinuation, and week 48 or 96. Resistance development during firstline STB therapy was infrequent: 2.3% of STB-treated subjects through 96 weeks. Pre-existing INSTI mutations were rare and had no effect on treatment response. Secondary resistance analyses of discontinuations before week 8 or with HIV-1 RNA between 50-399 copies/ ml revealed no additional STB subjects with resistance development.