Continuing a string of pipeline misfortune, Gilead Sciences ( GILD -0.55% ) reported lackluster late-stage trial data yesterday for momelotinib, a therapy under development for the treatment of myelofibrosis, a bone marrow disease. Momelotinib's underwhelming efficacy compared with Incyte Corporation 's ( INCY -1.65% ) Jakafi suggests the new drug is unlikely to displace Jakafi as the go-to therapy in the indication. That's bad news for Gilead Sciences, especially at a time when management is struggling to offset its sliding hepatitis C drug sales, but it's good news for Incyte because it means Jakafi isn't likely to lose market share.