RecruitingPhase 1Drug trialStudy of Pelabresib add-on to Ruxolitinib in Japanese Adult Patients With MyelofibrosisThis Phase 1b, multicenter, open-label study aims to evaluate the safety, pharmacokinetics (PK), and preliminary efficacy of pelabresib as add-on to ruxolitinib in Japanese patients with myelofibrosis (MF).