PAXIS Trial Study Design & Eligibility Criteria

Study Design

PAXIS study design

VEXAS, Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic; mg, milligrams; GC, Glucocorticoid; EOW, End of Week

aPatients who are stable on GC doses of 10-14 mg daily in addition to another non-GC anti-inflammatory therapy at Screening who have a previously documented VEXAS flare on GC monotherapy at a dose of ≥10 mg may be eligible, provided their GC dose is escalated to 15-45mg daily after washout.

bTime periods for washout are variable based on type of non-GC anti-inflammatory therapy

Trial Eligibility Criteria

Key Inclusion Criteria

  • Documented evidence of a pathogenic mutation (M41 or neighboring splice site) in UBA1
  • Current or documented evidence of past inflammatory involvement within 6 months prior to enrollment
  • Receiving ongoing GC therapy at a stable prednisone or prednisolone dose of 15-45 mg/day
    • Patients who are stable on GC doses of 10-14 mg/day in addition to another non-GC anti-inflammatory therapy screening who have a previously documented VEXAS flare on a GC dose ≥10 mg/day may be eligible provided that their GC dose is escalated to 15-45 mg/day after washout
  • Karnofsky Performance Status ≥50%
  • Adequate hepatic and renal function
  • Absolute neutrophil count ≥500/µL
  • Platelet count ≥25 x 109/L
  • Peripheral blasts <5%

Key Exclusion Criteria

  • Prior allogeneic hematopoietic stem cell transplant (allo-HSCT) or solid organ transplant (other than corneal)
  • Current use of systemic GCs for conditions other than VEXAS syndrome
  • More than one prior admission to an intensive care unit due to a VEXAS Syndrome flare within the prior 6 months
  • Received ≥9 units of intensive red blood cell (RBC) transfusions in the 90 days prior to enrollment
  • Known concurrent myelodysplastic syndrome (MDS) requiring antineoplastic treatment, or allo-HSCT, or known high-risk MDS based on the Revised International Prognostic Scoring System (IPSS-R). Patients who do not meet these criteria may enroll.
  • Malignancy within 1 year prior to enrollment with the exception of MDS (per exclusion criteria), curatively treated non-melanoma skin cancer, or curatively treated carcinoma in situ. Patients with pre-malignant hematologic condition (e.g., monoclonal gammopathy of unknown significance [MGUS], clonal cytopenia of unknown significance may enroll.
  • Exposure to hypomethylating agents (HMA) within 6 months prior to enrollment, or exposure to more than 4 cycles of HMAs at any time
  • Exposure to non-GC anti-inflammatory therapy or hematologic support therapy within protocol defined timeframes prior to enrollment*
  • Exposure to anti-platelet therapy with the exception of low-dose aspirin (≤100 mg daily) within 28 days prior to enrollment
  • Grade ≥2 bleeding within the prior 3 months, unless precipitated by an inciting event
  • History of clinically significant cardiovascular disease, or clinically significant abnormalities in rhythm or conduction during Screening, including:
    • QTc > 480msec
    • Grade ≥3 cardiac event within the prior 3 months
  • New thrombosis within the prior 60 days

*Anti-CD20 agents (e.g., rituximab): 180 days, Anti-IL-23 agents (e.g., ustekinumab): 90 days, Anti-TNFα except for etanercept (e.g., infliximab): 60 days, Canakinumab: 60 days, Intravenous anti-IL-6 agents (e.g., tocilizumab): 42 days, Subcutaneous anti-IL-6 agents: 28 days, Anti-IL-17 agents (e.g., secukinumab): 28 days, Anti-integrins (e.g., vedolizumab): 60 days, Intravenous immunoglobulin: 28 days, Danazol, immunomodulatory imide drugs (ImiDs), luspatercept, or thrombopoietin receptor agonists: 28 days, Cytotoxic chemotherapy: 28 days, Etanercept: 21 days, Oral Janus kinase (JAK) inhibitors: 14 days, Anti-IL-1 agents except for canakinumab: 14 days, Any other non-GC anti-inflammatory therapy (e.g., mycophenolate, azathioprine, cyclosporine, sulfasalazine, methotrexate): 14 days

For additional information, visit:

ClinicalTrials.gov EU CTIS

Pacritinib (commercially known as VONJO®) was approved by U.S. Food and Drug Administration (FDA) on February 28, 2022 for the treatment of adults with myelofibrosis with a platelet count below 50 x 109/L, and has since been marketed in the US under the brand name VONJO®. This indication is approved under accelerated approval based on spleen volume reduction. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).