JAK1 and myelofibrosis: Phase II trial investigating the addition of umbralisib to JAK1/2 (Janus Kinase 1/2) inhibitor ruxolitinib in patients with myelofibrosis (MF) demonstrated that combination treatment was well tolerated with an ORR of 37% and that umbralisib may re-sensitize patients with MF to JAK1/2 inhibitor ruxolitinib [159].