High glucocorticoid dependency and limited therapeutic response in Japanese patients with VEXAS syndrome: a...

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an autoinflammatory disease caused by somatic variants of the UBA1 gene. Due to uncertainty around treatment strategies and limited therapeutic options, this study aimed to characterise the clinical treatment and outcomes of VEXAS syndrome patients in Japan.

We retrospectively analysed data on clinical manifestations, treatments, and outcomes from 46 male patients diagnosed with VEXAS syndrome. Twelve patients at our institution were evaluated for remission using the French VEXAS group criteria.

All patients (median age at onset: 71.4 years) received systemic glucocorticoid therapy (mean maximum dose: 47.4 mg/day; mean minimum dose: 8.5 mg/day). Most patients required continuous glucocorticoid treatment of ≥10 mg/day, and tapering was generally difficult. Among the patients followed at our institution, only 42% (5/12) achieved complete remission at least once during follow-up. Tocilizumab was the most frequently administered immunosuppressant (n = 24, 52.2%); Janus kinase inhibitors and azacitidine, reported to be effective overseas, were prescribed in only three and two cases, respectively.

This study highlights the difficulty of treating patients with VEXAS syndrome in Japan. The development of more effective treatments is urgently needed to reduce glucocorticoid dependence and improve patient outcomes.