Study on Oral Navitoclax and Ruxolitinib Tablets Compared to Best Available Therapy for Reducing Spleen Size in Adults with Relapsed or Refractory Myelofibrosis

Inclusion Criteria

• Must complete a symptom assessment form for myelofibrosis on at least 4 out of 7 days before starting the study and agree to continue using an electronic device to record symptoms daily during the study.
• Have at least 2 symptoms with an average score of 3 or higher, or a total score of 12 or higher on the symptom assessment form.
• Have a confirmed diagnosis of primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocytopenia myelofibrosis with specific bone marrow scarring.
• Classified as intermediate-2 or high-risk myelofibrosis according to a specific scoring system.
• Currently on or have previously received treatment with the JAK2 inhibitor ruxolitinib and meet certain criteria related to spleen size and symptom control.
• Have a spleen that is enlarged by at least 5 cm below the rib cage or a spleen volume of 450 cm³ or more.
• Have a baseline platelet count of at least 100,000 per microliter.
• Have an ECOG performance status of 0, 1, or 2, indicating full activity or some restriction in strenuous activities.

Exclusion Criteria

• Have received previous treatment with certain types of drugs or more than one JAK2 inhibitor, or have had a stem cell transplant.
• Eligible for a stem cell transplant at the time of the study.
• Taking medication that affects blood clotting or platelet function within 3 days before starting the study, except for low-dose aspirin or low molecular weight heparin.
• Receiving treatment for another active cancer or myelofibrosis, including chemotherapy or radiation, unless enough time has passed since the last dose before starting the study.