Early treatment discontinuation was more common in older compared to younger patients (36% vs 25%, respectively) and was more frequently due to AE (48% vs 37%) than lack of efficacy (22% vs 33%). Anemia, defined as Hgb <10g/dl, or use of EPO/transfusion/ribavirin dose adjustment, was more frequent (77% vs 63%), more severe (nadir Hgb <8.5g/dl in 35% vs 18%), and more likely to be considered an SAE BTK inhibitor research buy (8% vs 3%) in older patients. The use of EPO (55% vs 33%) and blood transfusions
(23% vs 10%) was also more frequent among the older population (table). Among treatment naīve patients on TVR, rates of on-treatment virological response were similar between the older and younger patients (Week 4 Age > 65 (n=74) Age < 65 (n=856) Ureohydrolase Male Gender 51% 62% Cirrhosis 54% 56% Treatment naϊve/ Treatment TVR/BOC 39%/72%/28% 42%/77%/23% SAE% 15% 9% Anemia %/ Anemia SAE 77% / 8% 63% / 3% Management of anemia (not exclusive): RBV dose reduction/EPO use/Transfusion 49%/30%/23% 49%/15%/10% Decompensating event 5% 4% Infection/ Infection SAE 24%/3% 22%/3% Discontinued all HCV drugs Due to AE/Due to lack of efficacy 36% 48%/22% 25% 37%/36% Disclosures: Tuesdae Stainbrook – Advisory Committees or Review Panels: Kadmon Pharmaceutical, Gilead, Janssen Therapeutics; Speaking and Teaching: Genetech, Merck, Vertex Smruti Mohanty – Grant/Research Support: Genentech; Speaking and Teaching: Genentech, Merck Abdullah Mubarak – Speaking and Teaching: Salix Pharmaceuticals, Genetech, Vertex, Merck Prashant K. Pandya – Advisory Committees or Review Panels: Gilead; Grant/Research Support: Genentech, Merck; Speaking and Teaching: Genentech, Vertex, Onyx, Bayer Michael W. Fried – Consulting: Genentech, Merck, Abbvie, Vertex, Janssen, Bristol Myers Squibb, Gilead; Grant/Research Support: Genentech, Merck, AbbVie, Vertex, Janssen, Bristol Myers Squibb, Gilead; Patent Held/Filed: HCCPlex Ira M.