Initiation of belimumab with higher daily prednisolone is effective for rapid glucocorticoid reduction: A 96-week retrospective study.

Objectives: For appropriate glucocorticoid (GC) reduction, we investigated the optimal strategy including baseline factors that could reduce GC more than 50% with 96 weeks of belimumab.

Methods: This is a retrospective cohort study of Kakogawa Central City hospital from 2019 to 2023. We identified SLE patients who were receiving 200 mg of belimumab weekly by subcutaneous injection for 96 weeks. The background at baseline, trends in clinical indicators, and factors involved in GC reduction were statistically analyzed. Finally, univariate and multivariate logistic analyses were carried out to identify baseline factors associated ≥50% GC reduction at 96 weeks.

Results: Forty-seven patients were enrolled, with a median daily prednisolone of 5 mg. Almost 90% of them received concomitant immunosuppressants and/or hydroxychloroquine. Serological indices, daily GC dose, and SLEDAI-2K scores showed significant improvement in 96 weeks. At baseline, a significant negative correlation has been shown between the daily dose of GC and the duration from onset or last flare, as well as C4 levels. At 96 weeks, GC reduction rate and SLEDAI-2K scores were negatively correlated with duration from onset or last flare to initiation of belimumab. Mycophenolate mofetil use was significantly frequent in patients with lupus nephritis (LN), which also correlated with the frequency of past flares. In addition, LN presence was associated with higher SLEDAI-2K scores at 96 weeks, and baseline SLEDAI-2K ≥10 was associated with significantly higher GC dose at 96 weeks. Univariate analysis of the factor contributing to achieving ≥50% GC reduction at 96 weeks has pointed shorter disease duration and higher daily GC dose at baseline as significant variables. Finally, we performed a multivariate analysis by combining above two items with age, which extracted the higher daily GC dose at baseline as a significant variable (OR (95% CI) 1.25 (1.00 to 1.56), p = .047).

Conclusions: Our study showed that a delay in belimumab initiation led to higher SLEDAI-2K score and difficulty in achieving a 50% GC reduction at 96 weeks. Since GC-related adverse events increase with long-term administration of GC though with small daily doses, we proposed here that belimumab should be started in combination with higher daily prednisolone.