Belimumab, Azathioprine Did Not Lower Risk for Relapse in ANCA-Associated Vasculitis

Belimumab administered in combination with glucocorticoids and azathioprine did not lower the risk for relapse in patients with antineutrophil cytoplasm antibody (ANCA)-associated vasculitis, according to recent results published in Arthritis & Rheumatology.

Researchers conducted a randomized, double-blind, controlled trial of 105 patients with ANCA-associated vasculitis who were assigned to receive either belimumab (n=53) or placebo (n=52). All patients were given oral glucocorticoids (≤10 mg/d), azathioprine (2 mg/kg/d), and induction therapy with cyclophosphamide, rituximab, and glucocorticoids. Study participants received a single dose of belimumab 10 mg/kg intravenously, with subsequent doses were given at days 14 and 28 and every 28 days after, or placebo. The primary end point was time to reach the first protocol-specified event, defined using various factors, including the Birmingham Vasculitis Activity Score.

After statistical analysis, the researchers found that patients treated with belimumab did not lower the risk for protocol-specified events (adjusted hazard ratio [aHR], 1.07; 95% CI, 0.44-2.59; P =.884) or for vasculitis relapse (aHR, 0.88; 95% CI, 0.29-2.65; P =.821) vs placebo. In addition, the investigators reported a higher rate of adverse events in the belimumab group (92.5%) compared with placebo (82.7%).

The primary study limitation was the small sample size, which reduced the statistical power for the primary endpoint.

“Belimumab plus azathioprine and glucocorticoids for the maintenance of remission in [ANCA-associated vasculitis] did not reduce risk of relapse,” the researchers wrote.

“Future studies regarding the maintenance of remission in [ANCA-associated vasculitis] with belimumab as monotherapy may increase the ability of the trial to detect potential treatment benefit,” they concluded.

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Reference

Jayne D, Blockmans D, Luqmani R, et al. Efficacy and safety of belimumab and azathioprine for maintenance of remission in ANCA-associated vasculitis: a randomized controlled study [published online January 22, 2019]. Arthritis Rheumatol. doi: 10.1002/art.40802