Tirabrutinib impresses in refractory pemphigus trial

Use of the highly selective oral Bruton’s tyrosine kinase inhibitor tirabrutinib appears effective in the treatment of patients with refractory pemphigus, inducing remission and cutting oral corticosteroid use without major safety concerns, according to data from a phase II trial.

The multicentre, open-label trial included 16 patients (mean age 52.5 years, 50 percent male) who had refractory pemphigus, despite treatment with an oral corticosteroid and adjuvant therapies. All patients were given postprandial oral tirabrutinib 80 mg once daily for 52 weeks. After 16 weeks of treatment, the corticosteroid dose was reduced to ≤10 mg/day of prednisolone equivalent.

At week 24 following treatment initiation, the primary endpoint of complete remission occurred in three out of 16 patients, yielding a rate of 18.8 percent (95 percent confidence interval, 6.6–43.0).

By week 52, there were 10 patients (62.5 percent) who exhibited remission. The number of patients who achieved complete remission was eight (50.0 percent).

Meanwhile, the mean prednisolone dose dropped from 17.03 at baseline to 7.65 mg/day at week 52.

Adverse events (AEs) occurred in 87.5 percent of patients, and adverse drug reactions were recorded in 43.8 percent. Serious AEs and grade ≥3 AEs were not deemed to be related to treatment with tirabrutinib.

The findings suggest that oral tirabrutinib may be a new treatment option for patients with refractory pemphigus.