Inebilizumab helps prevent flare-ups in IgG4-related disease

CD19-targeted B-cell depletion with inebilizumab appears to reduce the risk of flares and increase the likelihood of flare-free complete remission at 1 year in patients with IgG4-related disease, according to the phase III MITIGATE trial.

A total of 135 adult patients with active IgG4-related disease were randomized to receive intravenous infusions of inebilizumab 300 mg on days 1 and 15 and week 26 (n=68) or placebo (n=67) for a 52-week treatment period. Patients in both groups received identical glucocorticoid tapers. Glucocorticoids were allowed to treat disease flares, but background immunosuppressants were not permitted.

First treated, adjudicated disease flare during the treatment period was the primary endpoint, assessed in a time-to-event analysis. Key secondary endpoints included annualized flare rate and treatment-free and glucocorticoid-free complete remission.

Compared with placebo, inebilizumab was associated with associated with 87-percent lower risk of flare (10 percent vs 60 percent; hazard ratio, 0.13, 95 percent confidence interval [CI], 0.06–0.28; p<0.001). Furthermore, the annualized flare rate was lower with inebilizumab than with placebo (rate ratio, 0.14, 95 percent CI, 0.06–0.31; p<0.001).

The odds flare-free, treatment-free complete remission were more than fourfold greater in the inebilizumab group than in the placebo group (odds ratio [OR], 4.68, 95 percent CI, 2.21–9.91; p<0.001), as were the odds of flare-free, glucocorticoid-free complete remission (OR, 4.96, 95 percent CI, 2.34–10.52; p<0.001).

During the treatment period, serious adverse events occurred in 12 patients (18 percent) on inebilizumab and in six (9 percent) on placebo.