A Phase 2 interventional study of Momelotinib treatment in VEXAS Syndome and Myelo Dysplastic Syndrome, sponsored by Groupe Francophone des Myelodysplasies. Recruiting at 11 sites in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by Groupe Francophone des Myelodysplasies · Phase 2, Interventional, and Treatment
Multicenter, phase II trial with safety run-in to evaluate the efficacy and safety of momelotinib in patients with VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory and Somatic) syndrome with or without associated myelodysplastic syndrome (MDS).
The study will consist of two consecutive steps, a dose-finding safety run-in and a single-arm prospective phase II.
During safety run-in phase, three fixed dose levels will be tested according to a 3+3 design, using cohorts of size 3 in order to establish the maximum tolerated dose.
After this safety run-in phase, patients included in phase II will be treated with momelotinib at the maximum tolerated dose preliminary fixed.
Patients included in the phase II will receive momelotinib continuously until disease progression or loss of response, at physician's discretion.
All patients included in the study will receive glucocorticoids (prednisone/prednisolone equivalent) at baseline (at least > 10mg/day).
Response assessment regarding VEXAS related symptoms will be evaluated after 4, 12, 24 and 48 weeks. Response assessment regarding MDS features will be evaluated at 12 and 24 weeks.
During safety run-in phase, the three fixed dose levels tested are :
Baseline steroids daily dose required for VEXAS inflammatory manifestations will be defined during screening period (28 days period) for each patient. It is defined as the minimal daily dose of steroids used in the last 14 days prior momelotinib onset (according to physician disposition) that allow disease control. In case of related VEXAS inflammatory manifestation during screening period with a first fixed dose, an increased dose of steroids should be evaluated during at least an extra 14 days prior momelotinib onset. This baseline dose defined during screening period will be used for response criteria during follow-up.
Momelotinib treatment will be discontinued after 24 weeks at optimal dosing regimen (up to 300 mg/day), in case of absence of response.
Treatment might also be discontinued during follow-up in case of loss of response/hematological progression or non-tolerable adverse event.
1,997 studies on the registry are indexed under Myelodysplastic Syndromes; 324 are open to participants now.
This study's planned enrollment of 57 is above the median of 40 across 1,611 interventional studies indexed under Myelodysplastic Syndromes.
Browse Myelodysplastic Syndromes studies →Groupe Francophone des Myelodysplasies is the lead sponsor of 44 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Women of (i.e., women who are pre-menopausal or not surgically sterile) must:
Male patients must:
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.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
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.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
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.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
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.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Allogeneic and autologous transplant
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
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.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
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.
Patients will receive momelotinib.
Drug: Momelotinib treatment
Patients included will receive momelotinib continuously until disease progression or loss of response, at physician's discretion.
Determination of the maximum tolerated dose of momelotinib
The maximum tolerated dose (MTD) is defined by a target dose-limiting toxicities (DLT) rate of 30%, assessed during the observation window by a 3+3 design. The 3+3 design will enroll a first cohort of 3 patients at the starting dose of 200 mg/d: * If 0 of the 3 patients at the dose of 200 mg/d experienced a DLT during the first 4-week cycle of momelotinib, the dose will escalate to 300 mg/d for the next cohort. * If 1 of the 3 patients at the dose of 200 mg/d has a DLT, a cohort of three additional patients will be treated at the same dose of 200 mg/d. * If \> 1 patient of the 3 patients at the dose of 200 mg/d have a DLT, the dose will de-escalate to 150 mg/d for the next cohort. The same process will be repeated until reaching the MTD. In total, between 6 and 18 patients will be enrolled during this safety run-in phase.
Time frame: First 4-week cycle of momelotinib treatment
Clinical efficacy
Determination of overall clinical response rate at 24 weeks after momelotinib initiation on VEXAS related symptoms (including complete (CR) or partial response (PR)) : * CR includes complete disappearance of symptoms related to systemic inflammation according to treating physician and daily dose of steroids ≤ 10 mg/d (equivalent prednisolone). * PR includes complete disappearance of symptoms related to systemic inflammation according to treating physician and reduction of at least 50% of daily dose steroids compared to baseline and/or daily dose of steroids \> 10 mg/d.
Time frame: During the 24 first weeks of momelotinib treatment
Pharmacokinetic
Concentrations of momelotinib and its major metabolite M21 will be determined in plasma samples using the currently approved bioanalytical methodology by Frontage Laboratories Inc. Pharmacokinetic sampling will be only performed for patients in safety run-in phase. Samples should be obtained at cycle 1 Day 8 and cycle 13 Day 8, at times following : Pre-dose then at 0.5 h, 1 h, 1.5 h, 2 h, 3 h, 4 h, 6 h, 8h and at 24 h post Day 8 dose.
Time frame: At cycle 1 Day 8-9 and cycle 13 Day 8-9
Incidence of Treatment-Emergent Adverse Events
Collection of Adverse events (AE), serious AE (SAE) and toxicities as measured by NCI CTCAE (National Cancer Institute Common Terminology Criteria for Adverse Events) v5.0
Time frame: From enrollment to the end of treatment at 48 weeks
Response
Determination of overall clinical response rates (including Complete Response or Partial Response) and biological response rates (complete or partial)
Time frame: After 4, 12, 24 and 48 weeks of momelotinib treatment
Hematological response
Erythroid hematological improvement will be assessed by the investigators according to IWG 2018 criteria through collection of transfusion records and hematology parameters.
Time frame: After 16 weeks of momelotinib treatment
Steroids dose reduction
Steroids dose reduction compared to baseline and/or steroids withdrawal rates
Time frame: After 24 weeks of momelotinib treatment
Overall survival
Overall survival assessment
Time frame: From enrollment to the end of treatment at 12 months
Myelodysplastic syndrome (MDS) evolution
Changes in the underlying MDS from baseline, at 12 and 24 weeks, including MDS progression based on hematological, cytogenetic and molecular analysis
Time frame: From baseline at 12 and 24 weeks of momelotinib treatment
Duration of response
Duration of response on VEXAS symptoms defined as the time from the date of initial documentation of a clinical response (Complete Response or Partial Response) to the date of first documented evidence of relapse or death
Time frame: From enrollment to the end of treatment at 48 weeks
Best clinical response
Determination of time to the first and best clinical response
Time frame: From enrollment to the end of treatment at 48 weeks
RBC independency
Duration of Red Blood Count (RBC) independency in patients with RBC dependency at time of inclusion, according to IWG 2018 criteria
Time frame: From enrollment to the end of treatment at 48 weeks
UBA1 VAF
Evolution of UBA1 (Ubiquitin Like Modifier Activating Enzyme 1) VAF (Variant Allelic Frequency) from baseline to W4, W12 and W24 after momelotinib treatment
Time frame: From enrollment to the end of treatment at 24 weeks
Validation of the VEXAS personal scoring system (VPSS)
Measurement of VPSS to validate the score currently under development which would allow objectively quantifying the impact of VEXAS-related symptoms on patients' quality of life.
Time frame: After 4, 12 and 24 weeks of momelotinib treatment
Plan to share: No
No publications or documents are linked to this record.
Started Nov 2025 (actual). Primary completion is estimated for Jun 2028, 31 months after the start.
Of 227 non-industry phase 2 interventional studies under Myelodysplastic Syndromes, half reached primary completion within 76 months of starting (the median), counting those still running; a quarter within 44 and three quarters within 116. This study's planned 31 months is below that.
Counting every sponsor, half of 279 studies reached it within 66 months; a quarter within 40 and three quarters within 104.
How these figures are worked out, and which studies are left out of them.
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Groupe Francophone des Myelodysplasies