Rituximab superior to cyclophosphamide in AS-related ILD

Treatment with rituximab (RTX) results in better 2-year progression-free survival (PFS) compared to cyclophosphamide (CYC) despite similar PFS at 6 months in patients with antisynthetase syndrome (AS)-related interstitial lung disease (ILD), a study has shown.

The investigators carried out this observational retrospective study in three tertiary care centres between 2003 and 2016. Sixty-two patients with AS-related ILD and treated with either RTX or CYC with at least 6 months of follow-up were included. PFS was defined according to the American Thoracic Society guidelines and assessed at 6 months and 2 years. All severe adverse events (AE) were recorded.

Of the patients, 34 received 2–12 monthly intravenous CYC pulses, followed by standard immunosuppressive treatment (IST) in 30 cases (88 percent), and 28 received RTX. Following the initial day 1 to 15 infusions, RTX was repeated every 6 months in 26 patients (93 percent), while 15 (54 percent) received another IST concomitantly. The two groups had similar median steroid dose.

RTX and CYC yielded comparable PFS at 6 months (92 percent and 85 percent, respectively), but the former was superior at 2 years (hazard ratio [HR], 0.263, 95 percent confidence interval [CI], 0.094–0.732; p=0.011).

Of note, lower diffusing lung capacity for carbon monoxide (DLCO) at baseline independently predicted poor 2-year PFS (HR, 0.965, 95 percent CI, 0.936–0.995; p=0.023). Both treatment groups had improvements in forced vital capacity and DLCO with no significant differences. Serious AEs were also comparable between RTX and CYC.

“AS-related ILD has a poor prognosis. Intravenous CYC and RTX are the main treatments currently used for moderate to severe ILD,” the investigators said.