An Open-Label Study to Enable Continued Treatment Access for Subjects Previously Enrolled in Studies of Ruxolitinib

Inclusion Criteria: * Currently enrolled and receiving treatment in an Incyte-sponsored clinical study of ruxolitinib that has completed or been terminated. * Currently tolerating treatment in the parent protocol. * Currently benefiting from the treatment with ruxolitinib alone, ruxolitinib plus background cancer therapy, or background cancer therapy alone, as determined by the investigator. * Have at least stable disease, as determined by the investigator. * Has demonstrated compliance, as assessed by the investigator, with the parent study protocol requirements. Exclusion Criteria: * Has been permanently discontinued from study treatment in the parent study for any reason. * Able to access ruxolitinib and/or background cancer therapy outside of the clinical study.