Gilead Sciences Inc. reported another late-stage pipeline setback after a pair of phase III trials evaluating JAK inhibitor momelotinib (formerly GS-0387) in myelofibrosis missed key endpoints. SIMPLIFY 1 and 2 were designed to compare momelotinib to Jakafi (ruxolitinib, Incyte Corp.) or best alternative therapy (BAT) in patients with primary myelofibrosis, post-polycythemia vera myelofibrosis or post-essential thrombocythemia myelofibrosis. In the double-blind, active-controlled SIMPLIFY 1 study, 432 myelofibrosis patients who were not previously treated with a JAK inhibitor were randomized (1-to-1) to momelotinib or ruxolitinib for 24 weeks. In SIMPLIFY-2, 156 patients previously treated with but not refractory to ruxolitinib were randomized (2-to-1) to momelotinib or BAT for 24 weeks.