NCT07357727 · Novartis Pharmaceuticals
A Phase 3 Study of Pelabresib (DAK539) and Ruxolitinib in Myelofibrosis (MF)
(MANIFEST-3)
What this study is about
The purpose of this trial is to evaluate whether treatment with pelabresib in combination with ruxolitinib leads to improved clinical outcomes compared to ruxolitinib alone in patients with primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (PPV-MF), or post-essential thrombocythemia myelofibrosis (PET-MF) who have not previously received Janus kinase (JAK) inhibitor therapy.
View original scientific description
The purpose of this trial is to evaluate whether treatment with pelabresib in combination with ruxolitinib leads to improved clinical outcomes compared to ruxolitinib alone in patients with primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (PPV-MF), or post-essential thrombocythemia myelofibrosis (PET-MF) who have not previously received Janus kinase (JAK) inhibitor therapy.
Interventions
DRUG
Pelabresib
Pelabresib monohydrate tablets
DRUG
Ruxolitinib
Ruxolitinib phosphate tablets
DRUG
Placebo
Matches pelabresib
Primary outcome measures
Number of Participants with Splenic Response (SVR35) by Central Radiology Reads at Week 24 in participants with baseline total symptom score (TSS) ≥ 25
Time frame: Week 24
Spleen Response (SVR35) is defined as achieving a reduction of at least 35 percent in spleen volume from baseline to Week 24, as measured by magnetic resonance imaging (MRI) or computed tomography (CT) scan, and assessed by a centralized radiology review in participants with baseline TSS ≥ 25.
Absolute change from baseline in total symptom score (TSS) at Week 24 in participants with baseline TSS ≥ 25
Time frame: Baseline, Week 24
Symptom improvement at Week 24 is defined as the absolute change from baseline in the total symptom score (TSS) at Week 24, as measured by the Myelofibrosis Symptom Assessment Form version 4.0 (MFSAF v4.0) in participants with baseline TSS ≥ 25.
Number of Participants with Splenic Response (SVR35) by Central Radiology Reads at Week 24 in participants with baseline TSS ≥ 15
Time frame: Week 24
Spleen Response (SVR35) is defined as achieving a reduction of at least 35 percent in spleen volume from baseline to Week 24, as measured by magnetic resonance imaging (MRI) or computed tomography (CT) scan, and assessed by a centralized radiology review in participants with baseline TSS ≥ 15.
Absolute change from baseline in total symptom score (TSS) at Week 24 in participants with baseline TSS ≥ 15
Time frame: Baseline, Week 24
Symptom improvement at Week 24 is defined as the absolute change from baseline in the total symptom score (TSS) at Week 24, as measured by the Myelofibrosis Symptom Assessment Form version 4.0 (MFSAF v4.0) in participants with baseline TSS ≥ 15.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants have diagnosis of primary myelofibrosis (PMF) or post-polycythemia vera myelofibrosis (post-PV MF) or post-essential thrombocythemia myelofibrosis (post-ET MF) according to the International Consensus Classification (ICC) of Myeloid Neoplasms and Acute Leukemias 2022
- DIPSS risk category of intermediate-1, intermediate-2 or high-risk
- Spleen volume ≥ 450 cm3 by CT or MRI scan (local read sufficient if no central read available)
- Have an average TSS of ≥15 within 7 days prior to randomization, using MFSAF v. 4.0 (at least 4 out of 7 TSS assessments required for average calculation)
- Participants with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1, or 2
- Blasts \<5% in peripheral blood. Assessment of blasts in peripheral blood is mandatory at screening
- Platelet count ≥ 100 x 10\^9/L in the absence of growth factors or transfusions for the previous 4 weeks Key
Exclusion criteria
- Prior splenectomy at any time or splenic irradiation in the previous 6 months
- Prior hematopoietic cell transplant or participant anticipated to receive a hematopoietic cell transplant within 24 weeks from the date of randomization
- Blasts ≥ 5% in bone marrow if results available at screening or history of accelerated phase (AP) or leukemic transformation
- History of a malignancy (other than MF, PPV-MF or PET-MF) in the past 3 years in need of systemic treatment
- Received any approved or investigational agent other than hydroxyurea or anagrelide for the treatment of MF within 14 days of first dose of study treatment or within 5 half-lives of the approved or investigational agent, whichever is longer
- Prior treatment with any JAK inhibitor or Bromodomain and extraterminal domain (BET) inhibitor Other protocol-defined inclusion/exclusion criteria may apply.
Where
- New Haven, Connecticut
- Atlanta, Georgia
- Berkeley Heights, New Jersey
- Columbus, Ohio
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 27, 2026 · Source of record for eligibility and locations