A Phase 2 interventional study of Momelotinib in Primary Myelofibrosis, sponsored by GlaxoSmithKline. Active, not recruiting at 112 sites in 20 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by GlaxoSmithKline · Phase 2, Interventional, and Treatment
Among 12 studies testing momelotinib in Primary Myelofibrosis — 3 open to participants now, 4 under way, none of them phase 3. momelotinib · Primary Myelofibrosis.
Among the 12 studies testing momelotinib in Primary Myelofibrosis, this one is the 3rd largest by enrollment, is the only one that started in 2018, is one of 5 in phase 2, and was the 8th registered.
625 studies on the registry are indexed under Primary Myelofibrosis; 124 are open to participants now.
Browse Primary Myelofibrosis studies →3 of the 12 studies testing momelotinib in Primary Myelofibrosis are open now, in 6 countries. Recruiting first, the newest first:
Massachusetts General Hospital · Sites in United States
GlaxoSmithKline · Sites in United States, Canada, France and 3 more countries
SWOG Cancer Research Network
By country, each count listing its studies:
momelotinib: first FDA approval 2023 (OJJAARA), first EMA approval 2024. What it is approved for, and how studies give it, is on its page →
Of the 101 Primary Myelofibrosis studies recruiting now, 83 (82%) set no upper age limit and 13 (13%) stop at 75 or younger; 10 take children under 18; 7 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
12 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 3 · Phase 2 7 · Phase 3 3 · Phase 4 1
First in 2009; this study’s year is marked. 1 started in 2018.
This study's enrollment of 237 is above the median of 43 across 489 interventional studies indexed under Primary Myelofibrosis.
Median enrollment 138 across the 12 interventional studies. Of the 8 that completed or were terminated, 5 (63%) have results posted.
This tab as a report to print or save as PDF → With an account.
10 of 12 have an industry lead sponsor. The 4 most frequent:
GlaxoSmithKline is the lead sponsor of 3,650 studies on the registry; 118 are open to participants now.
Of its 264 completed or terminated interventional studies of FDA-regulated products, 241 (91%) have results posted.
GlaxoSmithKline has 3 studies filed under Primary Myelofibrosis — fewer than ten, so there is no comparison to draw.
2 of the studies testing momelotinib in Primary Myelofibrosis that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT03441113GlaxoSmithKlineExtended Access of Momelotinib in Adults With Myelofibrosis | 2026-12-11 |
| NCT06517875GlaxoSmithKlineStudy of Momelotinib in Combination With Luspatercept in Participants With Transfusion Dependent Myelofibrosis | 2027-03-16 |
Among the 12 studies testing momelotinib in Primary Myelofibrosis, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This is an extended-access, long-term safety study for participants with primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (post-PV MF), or post-essential thrombocythemia myelofibrosis (post-ET MF) who have not experienced progression of disease and who have tolerated momelotinib (MMB) treatment while participating in previous MMB clinical trials (GS-US-352-0101 [NCT01969838], GS-US-352-1214 [NCT02101268], GS-US-352-1154 [NCT02124746] and SRA-MMB-301 [NCT04173494]). Participants in all cohorts continuing MMB treatment will discontinue MMB from the previous study and initiate MMB in this study at the same dose they were receiving in the previous study. Following the final data cut-off date, the study may move into the post analysis continuation of treatment (PACT) phase in which participants will continue to receive MMB and will be monitored and receive follow-up care in accordance with standard local clinical practice.
The criteria were revised on the registry on Oct 27, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CTCAE grade
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will continue to receive the same dosage regimen as in the previous MMB study GS-US-352-0101 until MMB receives regulatory approval and is commercially available, or development of the product ceases.
Drug: Momelotinib
Participants will continue to receive the same dosage regimen as in the previous MMB study GS-US-352-1214 until MMB receives regulatory approval and is commercially available, or development of the product ceases.
Drug: Momelotinib
Participants will continue to receive the same dosage regimen as in the previous MMB study GS-US-352-1154 until MMB receives regulatory approval and is commercially available, or development of the product ceases.
Drug: Momelotinib
Participants will continue to receive the same dosage regimen as in the previous MMB study SRA-MMB-301 until MMB receives regulatory approval and is commercially available, or development of the product ceases.
Drug: Momelotinib
Momelotinib will be administered
Also known as: GS-0387, CYT387
Number of Participants with treatment emergent adverse events (TEAEs) and serious adverse events (SAEs) by severity
Time frame: From study start until each participant transitions to PACT (up to approximately 556 weeks)
Overall survival (OS)
Time frame: From the start of the study drug until the date of death due to any cause or database lock, whichever comes first (up to approximately 556 weeks)
Leukemia free survival (LFS)
Time frame: From the start of the study drug until the date of any evidence of leukemic transformation and/or death due to any cause or database lock, whichever comes first (up to approximately 556 weeks)
Showing the first 100 of 112 sites across 20 countries. Choose a country and city above to see the rest.
Plan to share: No
Started May 2018 (actual). Primary completion is estimated for Dec 2026, 103 months after the start.
Of 30 industry-sponsored phase 2 interventional studies under Primary Myelofibrosis, half reached primary completion within 32 months of starting (the median), counting those still running; a quarter within 25 and three quarters within 66. This study's planned 103 months is above that.
Counting every sponsor, half of 98 studies reached it within 66 months; a quarter within 32 and three quarters within 111.
Completion moved once since we started tracking on Sep 25, 2026: Dec 2026 → Dec 2028, on Oct 27, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Momelotinib