Belimumab Safe, Effective at 6 Years Among Patients with SLE

In the extension period of a phase 3 trial to determine the safety and efficacy of belimumab in the treatment of patients with systemic lupus erythematosus (SLE), researchers found that the safety profile and disease control were favorable for up to 6 years and consistent with previous belimumab studies.

Eligible participants in the previous BEL11370 study were treated with intravenous belimumab 10mg/kg monthly for ≤6 years. The primary endpoint of this study was safety, with a secondary endpoint of SLE Responder Index (SRI)-4 response rate, severe SLE flares, and changes in prednisone use.

Of the total 424 patients, 359 (84.6%) had adverse events (AEs) and 96 (22.6%) had serious AEs. There were 26 patients (6.1%) who discontinued study treatment or withdrew from the study due to AEs. Of the AEs experienced, the postinfusion systemic reaction rate was 1.5 events/100 patients-years and herpes zoster infection rate was 3.0 events/100 patients-years; 0.4 events/100 patient-years were classified as a serious herpes zoster event. In year 0-1 there was 1 incidence of papillary thyroid cancer reported, and in year 3-4 there was 1 incidence of vaginal cancer reported.

There was a progressive increase of patients who had SRI-4 responses (year 1, week 24: 54.9%; year 5, week 48: 80.5%), while 55 patients (13.9%) experienced severe flares. Of the 335 patients with a baseline prednisone-equivalent dose of >7.5 mg/day, there was an increase of those with a dose reduction to ≤7.5 mg/day over time (year 1, week 24: 9.0%; year 5, week 48: 53.7%).

—Allison Casey

Reference:
Zhang F, Zheng J, Li Y, et al. Phase 3, long-term open-label extension period of safety and efficacy of belimumab in patients with systemic lupus erythematosus in China, for up to 6 years. RMD Open. Published online: April 15, 2022. doi: 10.1136/rmdopen-2021-001669