Primary MyelofibrosisPhase 2ODYSSEYNCT06517875
Study of Momelotinib in Combination With Luspatercept in Participants With Transfusion Dependent Myelofibrosis
A Phase 2 study testing Momelotinib and Luspatercept in people with Primary Myelofibrosis and Myelofibrosis; Primary Myelofibrosis; Post-polycythemia Vera Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis, run by GlaxoSmithKline at 33 sites in 6 countries.
Trial summary
The purpose of this Phase 2 study is to evaluate the efficacy and safety of momelotinib (MMB) in combination with luspatercept (LUSPA) in participants with transfusion dependence (TD) primary myelofibrosis (PMF) or Post-polycythemia vera (PV)/ essential thrombocythemia (ET) myelofibrosis (MF) who are either janus… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Primary Myelofibrosis, Myelofibrosis; Primary Myelofibrosis; Post-polycythemia Vera Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis
- What is being tested?
- Momelotinib and Luspatercept
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 68 participants
- Where
- 33 sitesin 6 countries
- Study dates
- 28 Feb 2025to 31 Jan 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Is age ≥18 years.
- Confirmed diagnosis of PMF in accordance with the World Health Organization (WHO) 2016 criteria, or Post-PV/ET myelofibrosis in accordance with the International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) criteria.
- JAKi naïve or previously treated with either ruxolitinib or fedratinib for PMF or Post-PV/ET myelofibrosis for ≥90 days, or ≥28 days if JAKi therapy is complicated by RBC transfusion requirement of ≥4 units in 8 weeks, or Grade 3/4 AEs of thrombocytopenia, anemia, or hematoma.
- High risk, intermediate-2, or intermediate-1 risk as defined by Dynamic International Prognostic Scoring System (DIPSS) [Passamonti, 2010] or DIPSS-plus [Gangat, 2011].
- TD defined as requiring RBC transfusion ≥4 units or HgB < 8 g/dL in the 8 weeks prior to the first dose of study treatment (NOTE: 2 consecutive Hgb < 8 g/dL, at least 1 week apart are required; Hgb values impacted by transfusions are excluded). Only transfusions given when Hgb levels are ≤9.5 g/dL are counted towards TD. RBC transfusions given for clinically overt bleeding, or accident/injury (as assessed by the investigator) are not counted towards TD.
Who cannot join
- History of intestinal disease, inflammatory bowel disease, major gastric surgery, or other gastrointestinal conditions (e.g., uncontrolled nausea, vomiting, malabsorption syndrome) likely to alter absorption of study intervention or result in inability to swallow oral medications.
- Participants with an invasive malignancy or history of invasive malignancy other than the disease under study within the last 5 years.
- Known clinically significant anemia due to iron, vitamin B12, or folate deficiencies, or autoimmune or hereditary hemolytic anemia, gastrointestinal bleeding, or thalassemia.
- Uncontrolled intercurrent illness:
- Active uncontrolled infection (participants receiving outpatient antibacterial and/or antiviral treatments for infection that is under control or as infection prophylaxis may be included in the trial);
- Significant active or chronic bleeding event ≥ Grade 2 per Common Terminology Criteria for Adverse Events (CTCAE) v5.0, within 4 weeks prior to the first dose of study treatment; or
Show all 34Show fewer
- Uncontrolled acute and chronic liver disease (e.g., Child-Pugh score ≥10) OR has current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, persistent jaundice, or cirrhosis. NOTE: Stable chronic liver disease (including Gilbert's syndrome or asymptomatic gallstones) is acceptable if participant otherwise meets entry criteria.
- Uncontrolled hypertension, defined as repeated elevations of systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, that is not resolved at the time of the first dose of study treatment.
- Any of the following in conditions within 6 months prior to the first dose of study intervention:
- Unstable angina pectoris; OR
- Symptomatic congestive heart failure; OR
- Uncontrolled cardiac arrhythmia
- QTc interval >450 msec or QTc >480 msec for participants with bundle branch block.
- Participants with stroke, deep venous thrombosis, pulmonary or arterial embolism within 6 months prior to the first dose of study intervention.
- History of porphyria.
- Presence of peripheral neuropathy ≥Grade 2 per CTCAE v5.0.
- Use of the following treatments within the time periods noted NOTE: All active anti-MF therapy must discontinue at least 1 week prior to the start of baseline MFSAF recording (Study Day -7):
- Active anti-MF therapy within 28 days or 5 half-lives, whichever is shorter (exception is prior JAKi therapy).
- Steroid use for the treatment of myelofibrosis is prohibited within 14 days prior to the first dose of study treatment until discontinuation of study treatment. Supportive care including steroids for non-myelofibrosis indications may be used.
- Potent cytochrome P450 3A4 (CYP3A4) inducers, except for rifampin and rifampicin, within 14 days prior to the first dose of study intervention.
- Any prior investigational agent for myelofibrosis within 4 weeks prior to the first dose of study treatment.
- Erythropoiesis stimulating agent (ESA) within 4 weeks prior to the first dose of study treatment.
- Splenic irradiation within 3 months prior to the first dose of study treatment.
- Prior treatment with MMB.
- Prior treatment with TGF-β pathway ligand traps (e.g., luspatercept or sotatercept).
- Prior splenectomy.
- Inability or unwillingness to comply with the protocol restrictions on myelofibrosis therapy and other medications prior to and during study treatment.
- Unresolved non-hematologic toxicities from prior therapies that are >Grade 1 per CTCAE v5.0 unless otherwise specified.
- Known positive status for human immunodeficiency virus (HIV).
- Hepatitis A, B, or C status as defined below:
- Chronic active or acute viral hepatitis A.
- Active Hepatitis B infection indicated by the presence of hepatitis B surface antigen (HBsAg) at screening or within 3 months prior to the first dose of study intervention.
- Positive hepatitis C antibody test result at screening or within 3 months before the first dose of study intervention. NOTE: Participants with positive hepatitis C antibody due to prior resolved disease can be enrolled, only if a confirmatory negative hepatitis C ribonucleic acid (RNA) test is obtained.
- Women who are already pregnant or lactating.
Trial locations and contacts
33 sites in 6 countries. Contact the study team or a site near you to ask about taking part.
33 sites in 6 countries
France7 sites, 7 recruiting
- Recruiting
GSK Investigational Site
Angers, 49933
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Brest, 29609
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Lyon, Rhône, 69004
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Nice, 06202
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Nîmes, 30029
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Paris, 75010
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Poitiers, 86021
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
Spain7 sites, 7 recruiting
- Recruiting
GSK Investigational Site
Badalona, 08005
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Barcelona, 8035
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Las Palmas, 35020
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Madrid, 28009
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Madrid, 28034
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Málaga, 29010
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Valencia, 46026
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
Italy6 sites, 6 recruiting
- Recruiting
GSK Investigational Site
Bologna, 40138
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Catania, 95123
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Florence, 50134
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Meldola FC, 47014
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Milan, MI, 20122
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Roma, 161
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
United States5 sites, 5 recruiting
- Recruiting
GSK Investigational Site
Ann Arbor, Michigan, 48109
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Houston, Texas, 77030
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Nashville, Tennessee, 37203
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
New York, New York, 10032
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Seattle, Washington, 98109
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
Canada4 sites, 4 recruiting
- Recruiting
GSK Investigational Site
Montreal, Quebec, H3T 1E2
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Montreal, Quebec, H4A 3J1
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Toronto, Ontario, M5G 2M9
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Vancouver, British Columbia, V6Z 1Y6
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
Germany4 sites, 4 recruiting
- Recruiting
GSK Investigational Site
Essen, North Rhine-Westphalia, 45147
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Jena, Thuringia, 07747
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Lübeck, 23538
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
- Recruiting
GSK Investigational Site
Mannheim, 68167
US GSK Clinical Trials Call Center, 877-379-3718, GSKClinicalSupportHD@gsk.com
EU GSK Clinical Trials Call Centre, +44 (0) 20 8990 4466, GSKClinicalSupportHD@gsk.com
About this study
Official title: A Phase 2 Open-label Study to Evaluate Momelotinib in Combination With Luspatercept in Participants With Transfusion Dependent Primary or Secondary Myelofibrosis
The purpose of this Phase 2 study is to evaluate the efficacy and safety of momelotinib (MMB) in combination with luspatercept (LUSPA) in participants with transfusion dependence (TD) primary myelofibrosis (PMF) or Post-polycythemia vera (PV)/ essential thrombocythemia (ET) myelofibrosis (MF) who are either janus kinase (JAK) inhibitor (JAKi) naïve or experienced.
- Conditions
- Primary Myelofibrosis, Myelofibrosis; Primary Myelofibrosis; Post-polycythemia Vera Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis
- Being tested
- Momelotinib, Luspatercept
- Keywords
- Momelotinib; Luspatercept; Primary Myelofibrosis; Secondary Myelofibrosis; JAK inhibitor; anemia transfusion; Ojjara; Omjjara; Reblozyl
- Medical subject headings
- Primary Myelofibrosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MomelotinibDrug
Also called Ojjaara; CYT387
Momelotinib will be administered orally.
LuspaterceptDrug
Also called REBLOZYL; ACE-536
Luspatercept will be administered subcutaneously.
| Study group | Role | What they receive |
|---|---|---|
| Momelotinib + Luspatercept | Experimental | Participants with transfusion dependent primary myelofibrosis or post- PV/ ET myelofibrosis that is JAKi naïve or JAKi experienced will receive momelotinib and luspatercept. Receives: Drug: Momelotinib; Drug: Luspatercept |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants with TI Response by Week 24
TI response is defined as not requiring red blood cell (RBC) transfusion (except in the case of clinically overt bleeding) for any ≥12-week interval.
Measured: Up to Week 24
Secondary outcomes (5)
Number of Participants with Adverse Events (AEs), Serious Adverse Events (SAEs), and AEs Leading to Discontinuation
Measured: Up to approximately 36 weeks
Number of Participants with Clinically Important Changes in Laboratory Parameters, Vital Signs, and Eastern Cooperative Oncology Group (ECOG) Performance Status
Measured: Up to Week 24
Percentage of Participants with TI at the End of Week 24
TI was defined as not requiring RBC transfusion (except in the case of clinically overt bleeding) for ≥12 weeks preceding Week 24, with all hemoglobin (Hgb) levels during the ≥12-week interval of ≥8 g/dL (except in the case of clinically overt bleeding).
Measured: Up to Week 24
Plasma Concentration of MMB
Measured: Up to Week 24
Plasma Concentration of Morpholino Lactam (M21)
Measured: Up to Week 24
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2024
- Study start28 Feb 2025
- Primary completion16 Mar 2027 (estimated)
- Study completion31 Jan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary MyelofibrosisStudies of the same condition, open and under way.
- More trials run by GlaxoSmithKlineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 68 participants (estimated)
Sponsor and investigators
- Lead sponsor
- GlaxoSmithKline
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06517875
- Sponsor's protocol ID
- 220752
- Other IDs
- 2024-518225-15, 2024-518225-15-00
- Acronym
- ODYSSEY
- Status last verified
- Nov 2026
- First submitted
- 19 Jul 2024
- Last updated
- 4 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Open-label Study to Evaluate Momelotinib in Combination With Luspatercept in Participants With Transfusion Dependent Primary or Secondary Myelofibrosis
- ClinicalTrials.gov ID
- NCT06517875
- Acronym / sponsor ID
- ODYSSEY / 220752
- Conditions
- Primary Myelofibrosis, Myelofibrosis; Primary Myelofibrosis; Post-polycythemia Vera Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis
- Keywords
- Momelotinib; Luspatercept; Primary Myelofibrosis; Secondary Myelofibrosis; JAK inhibitor; anemia transfusion; Ojjara; Omjjara; Reblozyl
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 68 participants (estimated)
- Lead sponsor
- GlaxoSmithKlineIndustry (pharma, biotech, devices)
- Study start
- 28 Feb 2025 (actual)
- Primary completion
- 16 Mar 2027 (estimated)
- Study completion
- 31 Jan 2029 (estimated)
- First posted
- 24 Jul 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this Phase 2 study is to evaluate the efficacy and safety of momelotinib (MMB) in combination with luspatercept (LUSPA) in participants with transfusion dependence (TD) primary myelofibrosis (PMF) or Post-polycythemia vera (PV)/ essential thrombocythemia (ET) myelofibrosis (MF) who are either janus kinase (JAK) inhibitor (JAKi) naïve or experienced.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Momelotinib + Luspatercept | Experimental | Drug: Momelotinib, Drug: LuspaterceptParticipants with transfusion dependent primary myelofibrosis or post- PV/ ET myelofibrosis that is JAKi naïve or JAKi experienced will receive momelotinib and luspatercept. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Is age ≥18 years.
- Confirmed diagnosis of PMF in accordance with the World Health Organization (WHO) 2016 criteria, or Post-PV/ET myelofibrosis in accordance with the International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) criteria.
- JAKi naïve or previously treated with either ruxolitinib or fedratinib for PMF or Post-PV/ET myelofibrosis for ≥90 days, or ≥28 days if JAKi therapy is complicated by RBC transfusion requirement of ≥4 units in 8 weeks, or Grade 3/4 AEs of thrombocytopenia, anemia, or hematoma.
- High risk, intermediate-2, or intermediate-1 risk as defined by Dynamic International Prognostic Scoring System (DIPSS) [Passamonti, 2010] or DIPSS-plus [Gangat, 2011].
- TD defined as requiring RBC transfusion ≥4 units or HgB < 8 g/dL in the 8 weeks prior to the first dose of study treatment (NOTE: 2 consecutive Hgb < 8 g/dL, at least 1 week apart are required; Hgb values impacted by transfusions are excluded). Only transfusions given when Hgb levels are ≤9.5 g/dL are counted towards TD. RBC transfusions given for clinically overt bleeding, or accident/injury (as assessed by the investigator) are not counted towards TD.
Key exclusion criteria (34 listed)
- History of intestinal disease, inflammatory bowel disease, major gastric surgery, or other gastrointestinal conditions (e.g., uncontrolled nausea, vomiting, malabsorption syndrome) likely to alter absorption of study intervention or result in inability to swallow oral medications.
- Participants with an invasive malignancy or history of invasive malignancy other than the disease under study within the last 5 years.
- Known clinically significant anemia due to iron, vitamin B12, or folate deficiencies, or autoimmune or hereditary hemolytic anemia, gastrointestinal bleeding, or thalassemia.
- Uncontrolled intercurrent illness:
- Uncontrolled hypertension, defined as repeated elevations of systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, that is not resolved at the time of the first dose of study treatment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MomelotinibAlso: Ojjaara; CYT387Momelotinib will be administered orally. | Drug | Momelotinib + Luspatercept |
| LuspaterceptAlso: REBLOZYL; ACE-536Luspatercept will be administered subcutaneously. | Drug | Momelotinib + Luspatercept |
Primary outcome
Percentage of Participants with TI Response by Week 24
Time frame: Up to Week 24
TI response is defined as not requiring red blood cell (RBC) transfusion (except in the case of clinically overt bleeding) for any ≥12-week interval.
5 secondary outcomes
Number of Participants with Adverse Events (AEs), Serious Adverse Events (SAEs), and AEs Leading to Discontinuation
Time frame: Up to approximately 36 weeks
Number of Participants with Clinically Important Changes in Laboratory Parameters, Vital Signs, and Eastern Cooperative Oncology Group (ECOG) Performance Status
Time frame: Up to Week 24
Percentage of Participants with TI at the End of Week 24
Time frame: Up to Week 24
Plasma Concentration of MMB
Time frame: Up to Week 24
Plasma Concentration of Morpholino Lactam (M21)
Time frame: Up to Week 24
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Nov 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
33 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Momelotinib and Luspatercept in people with Primary Myelofibrosis and Myelofibrosis; Primary Myelofibrosis; Post-polycythemia Vera Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis, run by GlaxoSmithKline at 33 sites in 6 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 34 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 33 sites in France, Spain, Italy, United States, Canada and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact US GSK Clinical Trials Call Center (877-379-3718, GSKClinicalSupportHD@gsk.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of Participants with TI Response by Week 24 (time frame: Up to Week 24). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Nov 2026.