A Phase 2/3 interventional study of Momelotinib and Glucocorticoids in VEXAS Syndrome, sponsored by GlaxoSmithKline. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-01.
Sponsored by GlaxoSmithKline · Phase 2/3, Interventional, and Treatment
This study will assess the efficacy and safety of momelotinib in participants with a diagnosis of VEXAS.
Confirmed diagnosis of clinical VEXAS defined by:
A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:
Exclusion Criteria:
Use of the following treatments within the noted time periods referenced from date of randomization:
Any of the following conditions within 6 months prior to randomization:
Participants will receive momelotinib at dose level 1 along with glucocorticoids as a background therapy (prednisone or prednisolone). Due to adaptive design of the study, additional participants may be randomized to this arm in phase 3.
Drug: Momelotinib · Drug: Glucocorticoids
Participants will receive momelotinib at dose level 2 along with glucocorticoids as a background therapy (prednisone or prednisolone). Due to adaptive design of the study, additional participants may be randomized to this arm in phase 3
Drug: Momelotinib · Drug: Glucocorticoids
Participants will receive momelotinib matched placebo along with glucocorticoids as a background therapy(prednisone or prednisolone). Due to adaptive design of the study, additional participants may be randomized to this arm in phase 3
Drug: Glucocorticoids · Drug: Placebo
Momelotinib will be administered
Also known as: GSK3070785
Glucocorticoids (prednisone or prednisolone) will be administered
Placebo will be administered
ORR (Objective response rate) at Week 26
ORR is defined as the proportion of participants who have achieved complete response (CR) or partial response (PR) during the 26-week Primary Treatment Period.
Time frame: At Week 26
Phase 2: Percentage of participants with partial response (PR) or complete response (CR) at Week 26
Percentage of participants with PR or CR at Week 26 to support identification of the Recommended Phase 3 dose (RP3D)
Time frame: At Week 26
Phase 2: Number of participants with adverse events and clinically significant changes in laboratory parameters, and vital signs to support identification of the RP3D
Time frame: Up to 26 Weeks
Phase 2: Plasma concentrations of momelotinib and metabolite of momelotinib 21 (M21) to support identification of the RP3D
Time frame: Up to 26 Weeks
Number of flare-free days
Flare-free days are calendar days without clinical evidence of VEXAS flare and without treatment escalation. Total number of flare-free days is defined as the cumulative number of consecutive and non-consecutive flare-free days.
Time frame: Up to 26 Weeks
Duration of response (DoR)
DoR defined as the date of clinical response (CR or PR) to the date of relapse.
Time frame: Up to 104 Weeks
Number of flare-free days with glucocorticoid (GC) dose <=10 mg/day
Flare-free days are calendar days without clinical evidence of VEXAS flare and without treatment escalation. Total number of flare-free days is defined as the cumulative number of consecutive and non-consecutive flare-free days.
Time frame: Up to 104 Weeks
Percentage of participants achieving complete and partial biochemical response
Complete biological response is defined as complete or partial normalization of C-reactive protein.
Time frame: Up to 26 Weeks
Objective response rate (ORR) at Week 52
ORR is defined as the proportion of participants who have achieved complete response or partial response
Time frame: At Week 52
Number of Participants with Hematologic Improvement- Erythroid (HI-E) response per International Working Group (IWG) 2018 criteria
HI-E response is measured based on the combined incidence of: Low transfusion burden participants defined as absence of any transfusion for greater than or equal to (\>=)8 consecutive weeks. High transfusion burden participants: minor response defined as reduction by \>=50% of red blood cell (RBC) units for \>=8 consecutive weeks. Major response defined as absence of RBC transfusions for \>=8 consecutive weeks or longer up to 26 weeks.
Time frame: Up to 26 Weeks
Change from Baseline in Short Form 36 (SF-36) domain and summary scores
Short-Form 36 is a health-related survey that assesses quality of life covering 8 domains: vitality; physical functioning; bodily pain; general health perceptions; physical role functioning; emotional role functioning; social role functioning; and mental health. The domain scores are weighted to a scale ranging between 0 to 100, where higher score represents better health. The Physical Component Summary (PCS) and Mental Component Summary (MCS) scores are derived from the eight domain scores. These scores are standardized to a general U.S. population average of 50, with a standard deviation of 10. For both PCS and MCS, scores range from 0 to 100, higher scores indicate a better health outcome.
Time frame: Baseline and up to Week 48
Change from Baseline in European Organization for Research and Treatment of Cancer Item Library (EORTC IL) 479 score
The EORTC Item Library is a database containing \>1000 individual items from more than 70 EORTC quality of life measures. A subset of 7 items from the library were selected based on symptoms experienced by participants with VEXAS syndrome. Scores range from 1 to 100 with higher scores representing a higher ("worse") level of symptoms.
Time frame: Baseline and up to Week 156
Change From Baseline in Patient Reported Outcome Measurement Information System (PROMIS) Physical Function Short Form 10b
PROMIS Physical Function Short Form 10b consists of 10 questions; each with a 5-point response. PROMIS short form assesses self-reported capability of a participant rather than actual performance of physical activities. Higher scores indicate better functioning. Total possible range of scores is 10 to 50, with higher scores corresponding to a greater physical function ability.
Time frame: Baseline and up to Week 156
Change from Baseline in Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-FATIGUE)
The FACIT-Fatigue is a short, 13-item questionnaire that assesses self-reported fatigue and its associated impact on daily activities over the past 7 days. A higher score indicates a better outcome (no fatigue). The total score ranges from 0 to 52, with 0 being the worst possible score and 52 being the best possible score (indicating no fatigue).
Time frame: Baseline and up to Week 156
Changes from Baseline in Patient Global Impression of Severity (PGIS) scores
The PGIS is a single global question which asks participants to rate the severity of their VEXAS syndrome symptoms on a 5-point rating scale with response categories of "No symptoms", "Mild", "Moderate", "Severe", and "Very Severe." The PGIS scores ranges from 0 (absent) to 4 (very severe).
Time frame: Baseline and up to Week 156
Changes in Patient Global Impression of Change (PGIC) scores
The PGIC is a single global question which asks participants to rate the change in severity of their VEXAS syndrome symptoms since starting study medication using a 5-point rating scale with response categories of "much better", "a little better", "no change", "a little worse", "much worse". The PGIC score ranges from +2 (much better) to -2 (much worse).
Time frame: Baseline and up to Week 156
Changes from Baseline in European quality of life 5 dimensions 5 level version (EQ-5D-5L)
EQ-5D-5L is self-assessment questionnaire, consisting of 5 items covering 5 dimensions (mobility, self care, usual activities, pain/discomfort, and anxiety/depression). Each dimension is measured by 5-point Likert scale ranging from 1=no problems to 5=extreme problems.
Time frame: Baseline and up to Week 48
Changes from Baseline in European quality of life-Visual Analogue Scale (EQ-VAS)
The EQ-VAS records the respondents self-rated health on a vertical VAS, ranging from 0 to 100, where 0 represents the worst imaginable health and 100 represents the best imaginable health.
Time frame: Baseline and up to Week 48
Number of participants with adverse events (AEs) and Serious adverse events (SAEs)
Time frame: Up to Week 108
Number of participants with adverse events (AEs) and Serious adverse events (SAEs) by severity
Time frame: Up to Week 108
Number of participants with AEs leading to discontinuation or dose modifications
Time frame: Up to Week 108
Plasma concentration of momelotinib and M21
Time frame: Up to 26 Weeks
Overall Survival
Overall survival is defined as the time from randomization to the date of death due to any cause.
Time frame: At Months 12, 24 and 36
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Plan to share: No
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VEXAS syndrome
GlaxoSmithKline