Dr. Urowitz, of the Centre for Prognosis Studies in Rheumatic Diseases at the Toronto Western Hospital, also reported that magnitude of year-on-year organ damage progression was lower in patients treated with belimumab versus those treated only with standard of care. While 15.2% and 0.6% of belimumab-treated patients had a 1- or 2-point or higher increase in SDI, corresponding data in the standard of care–treated patients were 31.6% and 8%.
These data make an argument that belimumab could be given for longer periods of time, David Isenberg, MD, of University College London Hospital, said in an interview at the EULAR 2018 Congress (see video).
Dr. Urowitz and his associates used pooled data from two long-term extension (LTE) studies of two phase 3 belimumab clinical trials and data from the Toronto Lupus Cohort (TLC). A total of 181 patients from the BLISS LTE studies were matched, using propensity scoring, to 181 patients in the TLC to assess the primary outcome of organ damage progression at 5 years, and 323 patients in the BLISS LTE studies were matched to 323 in the TLC to look at the rate of organ damage progression over 1 year or more, and the year-on-year magnitude of change in organ damage over 5 years or more (Arthritis Rheum. 2018;77:177. Abstract OP0254).
In a separate presentation at the Congress, Ronald F. van Vollenhoven, MD, also reported on organ damage progression and the long-term safety of belimumab in a long-term extension in non-U.S. patients involving almost 700 patients.
“Organ damage accrual is, and remains, very limited,” said Dr. van Vollenhoven, professor of rheumatology at the University of Amsterdam. The majority of patients experienced no change in SDI scores from baseline (94.3%) to week 48 (87.7%) of each year of follow up out to 8 years, he said.
Importantly, “belimumab displayed a stable safety profile over 8 years of exposure and no new safety signals were observed,” Dr. van Vollenhoven said. He highlighted that the incidence of adverse events, serious adverse events, and adverse events leading to discontinuation were broadly similar to previous studies.
“We were specifically pleased to see no increase, and in fact a decrease, in psychiatric events as it had been raised as a concern, but it does not seem to pan out over time,” Dr. van Vollenhoven said. Overall, 11.7% of patients had depression, suicidal thoughts or self-harmed over the follow-up period, with the rate falling from 10.5% at baseline to 1.8% by year 6-7 (Arthritis Rheum. 2018;77:175. Abstract OP0252).
The belimumab studies were supported by GlaxoSmithKline. Dr. Urowitz disclosed receiving grant or research support from GSK as well as acting as a consultant to the company. Dr. Isenberg had no relevant financial conflicts of interest to disclose. Dr. van Vollenhoven disclosed receiving research support and grants from a variety of pharmaceutical companies including GSK and being the editor in chief of the journal Lupus Science & Medicine.
Sara Freeman is a freelance reporter with MDedge News.