NCT06782373

A Study to Assess the Effectiveness and Safety of Pacritinib in Patients With VEXAS Syndrome (PAXIS)

PAXIS: A Randomized, Double-blind, Placebo-controlled Dose-finding Phase 2 Study (Part 1) Followed by an Open-label Period (Part 2) to Assess the Efficacy and Safety of Pacritinib in Patients With VEXAS Syndrome

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 78 (estimated)
• Sponsor: Swedish Orphan Biovitrum · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This trial is to assess the effectiveness and safety of pacritinib in patients with VEXAS (i.e., Vacuoles in myeloid progenitors, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory manifestations, and somatic) syndrome. 78 participants will be enrolled, randomized to either pacritinib dose A, pacritinib dose B + placebo, or placebo. Randomization will be stratified by prescribed GC dose on the day of randomization.

Detailed description

This trial is a randomized, multicenter, double-blind, placebo-controlled phase 2 trial (Part 1) followed by an open-label treatment period (Part 2) designed to evaluate the efficacy and safety of pacritinib for the prevention of VEXAS flares after glucocorticoid (GC) taper. The trial will enroll participants ≥18 years with inflammatory VEXAS syndrome receiving ongoing GC therapy for ≥4 consecutive weeks, requiring between 15 and 45 mg daily (of prednisone / prednisolone or equivalent) at the time of enrollment (randomization). Participants will be randomized 1:1:1 to receive pacritinib dose A (n=26), pacritinib dose B plus placebo (n=26), or placebo (n=26) for up to 24 weeks during a double-blind treatment period, followed by treatment with pacritinib during an open-label treatment period for up to 48 weeks. Participants who complete the open-label treatment period at End of Week (EOW) 48 and who are benefitting from pacritinib in the opinion of the Investigator may continue to receive treatment for an additional 1 year on the extension period. Participants who discontinue study treatment will have a 30-day post-End of Treatment (EOT) follow-up period. Randomization will be stratified by prescribed GC dose on the day of randomization. All outcomes will be reported by treatment arm, and pair-wise comparison between each pacritinib arm and placebo will be performed in the double-blind treatment period. Participants who complete the double-blind treatment period at EOW 24 or meet Early Failure criteria at EOW 12 will transition to an open-label pacritinib treatment period through EOW 48. In addition, if a trial arm closes due to interim futility or safety, all participants currently randomized to that arm will transition to open-label treatment. The trial (including the double-blind and open-label treatment periods, as well as the extension period) is planned to end approximately 2 years from the first dose of the last participant.

Conditions

• VEXAS
• VEXAS Syndrome

Interventions

Type	Name	Description
DRUG	Pacritinib	Supplied in hard capsules.
DRUG	Placebo	Supplied in hard capsules.

Timeline

• Start date: 2025-05-28
• Primary completion: 2026-12-30
• Completion: 2028-05-22
• First posted: 2025-01-17
• Last updated: 2026-03-12

Locations

40 sites across 8 countries: United States, Canada, France, Germany, Italy, Japan, Spain, United Kingdom

Regulatory

• FDA-regulated drug study