Hope for rare disease: new drug trial for VEXAS syndrome begins

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age greater than equal to (\>=)18 years OR of legal age of consent in the jurisdiction in which the study is taking place, at the time of signing the Informed Consent Form. * Confirmed diagnosis of clinical VEXAS defined by: 1. Documented evidence of a canonical, pathogenic Ubiquitin-like modifier activating enzyme 1 (UBA1) mutation 2. Inflammatory manifestations: current or documented past involvement within 6 months of at least one organ system * Receiving glucocorticoid (GC) treatment (prednisone/prednisolone) for \>=4 consecutive weeks for \>=10 days prior to randomization. * A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: 1. Is a Participant of non-childbearing potential (PONCBP) OR 2. Is a Participant of childbearing potential (POCBP) and using a contraceptive method that is highly effective * Is capable of giving signed informed consent including compliance with the requirements and restrictions * Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 to 2 at the time of screening. * Has adequate organ function Exclusion Criteria: * More than 1 prior admission to an intensive care unit due to a VEXAS flare within the 6 months prior to randomization. * History of severe corticosteroid toxicity: uncontrolled concomitant cardiovascular, nervous system, pulmonary (including obstructive pulmonary disease), renal, hepatic, endocrine (including uncontrolled diabetes mellitus), psychiatric, osteoporosis/osteomalacia, glaucoma, corneal ulcers/injuries, nausea or vomiting or gastrointestinal disease. * High risk/very high risk Myelodysplastic syndrome (MDS), according to the Revised International Prognostic Scoring System (IPSS-R) with overall risk score \>3.5. * Peripheral blood blast counts \>=10%. * Multiple myeloma (all stages) and other active plasma cell dyscrasias requiring treatment. * Malignancy (except disease under study including Lower-risk myelodysplastic syndrome \[LR-MDS\]) that has progressed or required active treatment within the past (24 months) except for basal cell or squamous cell carcinomas of the skin or in-situ carcinomas). * Uncontrolled intercurrent illness within 12 weeks prior to initiation of momelotinib. * Ongoing adverse reaction(s) from prior therapy that have not recovered to Grade \<=1 per NCI CTCAE v6.0 or to the Baseline status preceding prior therapy * Psychiatric illness, social situation, or any other condition that would limit informed consent and/or compliance with trial requirements or may interfere with the interpretation of study results, as judged by Investigator or Sponsor. * Has any clinically significant gastrointestinal conditions or abnormalities that may alter absorption or swallowing * Known contraindication or hypersensitivity to momelotinib and its metabolites, or any of their excipients. * Presence of peripheral neuropathy \>=Grade 2 per NCI CTCAE v6.0. * Known history of disseminated mycobacterial infection. * Known positive status for human immunodeficiency virus (HIV). * Positive QuantiFERON (or other interferon gamma release assay) during Screening. * Unable to receive any Pneumocystis jiroveci pneumonia (PJP) medical prophylaxis * Known clinically significant anemia due to iron, vitamin B12 or folate deficiencies, or autoimmune or hereditary hemolytic anemia, gastrointestinal bleeding, or thalassemia. * More than 1 prior line of VEXAS directed therapy before or after VEXAS diagnosis or other medical condition. * Use of the following treatments within the noted time periods referenced from date of randomization: 1. VEXAS-directed therapies (washout period) up to 5 half-lives or up 14 days if half-life is \<3 days 2. Other non-GC anti-inflammatory therapies: for non-biologics): 14 days or five half-lives, whichever is longer; for biologics): 28 days or two half-lives whichever is longer. 3. Hematologic support therapy (e.g., ESAs, danazol, luspatercept, G-CSF): 4 weeks 4. Cell-depleting therapies such as anti-CD20 (rituximab): 12 months 5. Investigational agent from a class not otherwise specified: 5 half-lives or 60 days, whichever is longer * GC use for conditions other than VEXAS, which would interfere with adherence to the fixed GC taper regimen and/or to assessment of efficacy. * Chronic use of systemic corticosteroids for \>4 years or inability to withdraw corticosteroid treatment * Planned allogeneic HSCT for MDS or VEXAS, within 1 year. * Any major surgery within 28 days prior to randomization. * Prior allogeneic/autologous stem cell transplant or solid organ transplant (other than corneal). * Presence of peripheral neuropathy \>=Grade 2 per NCI CTCAE v6.0. * Hepatitis B or C active infection, unless protocol defined criteria are met. * Any of the following conditions within 6 months prior to randomization: 1. Unstable angina pectoris 2. Symptomatic congestive heart failure 3. Uncontrolled cardiac arrhythmia 4. QTc \>450 msec or QTc \>480 msec for participants with bundle branch block.