Belimumab efficacy maintained through 10 years in treatment of SLE

MADRID — Ten-year follow-up data for a cohort of patients with systemic lupus erythematosus who received belimumab showed that the drug maintained efficacy and tolerability, according to findings presented at the EULAR Annual Congress.

“We now have 10 years of experience with patients being given Benlysta [GlaxoSmithKline],” Daniel J. Wallace, MD, associate director of the Rheumatology Fellowship Program at Cedars Sinai Medical Center in Los Angeles, said during his presentation. The analysis is the final follow-up data for a modified intention-to-treat population that initially included 476 patients. The current data set included 296 patients treated with a 10 mg/kg who remained on treatment. The findings comprised approximately 2,461 patient-years of follow-up.

The presentation included “primarily safety” endpoints, along with SRI-4 response, according to Wallace. “There was no formal statistical analysis,” he said. “The analyses were exploratory in nature.”

Overall, adverse events occurred in 80.2% of the cohort, with serious adverse event rates ranging from 15% to 20%. The most common events were upper respiratory tract infections and arthralgia, according to Wallace. The SRI-4 response was seen in 82 of 126 patients, or nearly 60%, according to Wallace.

“The drug did not appear to lose effect over time and its efficacy was sustained,” he said.

BILAG-A or BILAG-B flare rates ranged from about 50% to 60%.

“[Selena Flare Index] SFI flares were about half that,” Wallace added. He noted the rate of SFI flares decreased with time. “Serious or severe SFI flares were almost nonexistent after the second or third year.”

Patients who received corticosteroids were able to substantially reduce their dose, with about 13% of patients discontinuing those therapies, according to the findings.

Wallace said the study population generally had SELENA-SLE disease activity index greater than 4, measurable lupus autoantibodies, were stable on standard systemic lupus erythematosus therapy and had severe active central nervous system lupus or lupus nephritis. The original design of the study included three different doses of the drug. Most patients in the study were female and in their 40s. They had lupus for about 10 years, he said.

“Patients in this continuing study had the longest duration of belimumab therapy recorded in a clinical trial program, with 44% of patients receiving the drug for 10 years,” Wallace said.

He suggested the findings were in alignment with the interim analysis of the study.

“The drug was well tolerated, with no apparent increase in adverse events or serious adverse events over time,” he said. “Efficacy was maintained through the study. This provides evidence of the long-term safety and efficacy of belimumab.” — by Rob Volansky

Reference:

Wallace DJ, et al. Abstract #OP0232. Presented at: EULAR Annual Congress; June. 14-17, 2017; Madrid.

Disclosure: Wallace reports receiving grant or research support from and consulting for GlaxoSmithKline.