4% (56) were receiving stable OST. The majority were male (66.1%, 37/56) and white (94.6%, 53/56), and the mean age was 47.9 years. Nine patients (16.1%) were treatment-experienced. One patient had compensated cirrhosis. Of the 56 patients, 54 (96.4%) achieved SVR12. A majority of patients (89.3%, 50/56) experienced at least 1 adverse event (AE), most of which were mild. Two patients (3.7%) experienced a serious AE. None of the patients on OST experienced virologic failure; 1 patient (1.8%) discontinued due to an AE at day 26, and 1 patient discontinued for non-compliance. Grade 3 bilirubin elevation occurred in 1 patient (1.8%); there were no grade 3 or greater

elevations in ALT, AST, or alkaline phos-phatase. Conclusions: In agreement with previous reports, the 3D regimen

with or without RBV was well tolerated Acalabrutinib ic50 in patients on stable OST, with a high SVR12 rate of 96.4%, and a favorable toxicity profile. check details These data suggest that this interferon-free regimen may be a suitable treatment option for this patient population. Disclosures: Massimo Puoti – Advisory Committees or Review Panels: GSK, Abbott, Janssen, MSD, Roche, Gilead Sciences, Novartis, GSK, Abbott, Janssen, MSD, Roche, Gilead Sciences, Novartis, GSK, Abbott, Janssen, MSD, Roche, Gilead Sciences, Novartis, GSK, Abbott, Janssen, MSD, Roche, Gilead Sciences, Novartis; Speaking and Teaching: BMS, BMS, BMS, BMS Curtis Cooper – Advisory Committees or Review Panels: Vertex, MERCK, Roche; Grant/Research Support: MERCK, Roche; Speaking and Teaching: Roche, MERCK Mark S. Sulkowski – Advisory Committees or Review Panels: Merck, AbbVie, Idenix, Janssen, Gilead, BMS, Pfizer; Grant/Research Support: Merck, AbbVie, BIPI, Vertex, Janssen, Gilead, BMS Graham R. Foster – Advisory Committees or Review Panels: GlaxoSmithKline, Novartis, Boehringer Ingelheim, Amino acid Tibotec, Chughai, Gilead, Janssen, Idenix, GlaxoSmithKline, Novartis, Roche, Tibotec, Chughai, Gilead, Merck, Janssen, Idenix, BMS; Board Membership: Boehringer Ingelheim; Grant/Research

Support: Chughai, Roche, Chughai; Speaking and Teaching: Roche, Gilead, Tibo-tec, Merck, BMS, Boehringer Ingelheim, Gilead, Janssen Thomas Berg – Advisory Committees or Review Panels: Gilead, BMS, Roche, Tibotec, Vertex, Jannsen, Novartis, Abbott, Merck; Consulting: Gilead, BMS, Roche, Tibotec; Vertex, Janssen; Grant/Research Support: Gilead, BMS, Roche, Tibotec; Vertex, Jannssen, Merck/MSD, Boehringer Ingelheim, Novartis; Speaking and Teaching: Gilead, BMS, Roche, Tibotec; Vertex, Janssen, Merck/MSD, Novartis, Merck, Bayer Erica Villa – Advisory Committees or Review Panels: Abbvie, GSK; Grant/ Research Support: MSD, Roche Federico Rodriguez-Perez – Advisory Committees or Review Panels: Merck, Bristol, Abbive Vinod Rustgi – Advisory Committees or Review Panels: Abbvie, Gilead; Grant/ Research Support: Abbvie, Gilead, BMS; Speaking and Teaching: Gilead, Genentech David L.