Belimumab and antimalarials combined against renal flares in patients treated for extra-renal systemic lupus erythematosus: results from 4 phase III clinical trials

OBJECTIVES

To determine the effect of antimalarial agents (AMA) and different doses and pharmaceutical forms of belimumab on preventing renal flares in patients with SLE treated for extra-renal disease.

METHODS

We pooled data from the BLISS-52, BLISS-76, BLISS-SC and BLISS-Northeast Asia trials of belimumab (n = 3225), that included patients with active SLE yet no severe ongoing nephritis. Participants were allocated to receive intravenous belimumab 1 mg/kg, intravenous belimumab 10 mg/kg, subcutaneous belimumab 200 mg, or placebo in addition to standard therapy. We estimated hazards of renal flare development throughout the study follow-up (52-76 weeks) using Cox regression analysis.

RESULTS

In total, 192 patients developed a renal flare after a median of 197 days. Compared with placebo, the risk of renal flares was lower among patients receiving intravenous belimumab 10 mg/kg (HR: 0.62; 95% CI: 0.41, 0.92; P = 0.018) and intravenous belimumab 1 mg/kg (HR: 0.42; 95% CI: 0.22, 0.79; P = 0.007), while no significant association was found for subcutaneous belimumab 200 mg. AMA use yielded a lower hazard of renal flares (HR: 0.66; 95% CI: 0.55, 0.78; P < 0.001). The protection conferred was enhanced when belimumab and AMA were co-administered; the lowest flare rate was observed for the combination intravenous belimumab 1 mg/kg and AMA (18.5 cases per 1000 person-years).

CONCLUSIONS

The protection conferred from belimumab against renal flare development in patients treated for extra-renal SLE appears enhanced when belimumab was administered along with AMA. The prominent effect of low-dose belimumab warrants investigation of the efficacy of intermediate belimumab doses.

CLINICAL TRIAL IDENTIFICATION

BLISS-52: NCT00424476; BLISS-76: NCT00410384; BLISS-SC: NCT01484496; BLISS-NEA: NCT01345253.

Predictors of renal flares in systemic lupus erythematosus: a post-hoc analysis of four phase III clinical trials of belimumab

OBJECTIVES

To identify predictors of renal flares in patients with SLE treated for active extra-renal disease.

METHODS

Data from four clinical trials of belimumab in SLE (BLISS-52, NCT00424476; BLISS-76, NCT00410384; BLISS-NEA, NCT01345253; BLISS-SC, NCT01484496) were used. Patients were assigned to belimumab or placebo on top of standard therapy. We investigated the performance of predictors of renal flares through 52-76 weeks using proportional hazards regression analysis.

RESULTS

Of 3225 participants, 192 developed at least one renal flare during follow-up, with the first occurring after a median time of 197 days. Current/former renal involvement (HR: 15.4; 95% CI: 8.3-28.2; p< 0.001), low serum albumin levels (HR 0.9; 95% CI: 0.8-0.9; p< 0.001), proteinuria (HR: 1.6; 95% CI: 1.5-1.7; p< 0.001), and low C3 levels (HR: 2.9; 95% CI: 2.1-4.1; p< 0.001) at baseline appeared robust determinants of renal flares. Anti-dsDNA positivity yielded an increased hazard for renal flares (HR: 2.1; 95% CI: 1.4-3.2; p< 0.001), which attenuated after adjustments. Anti-Sm positivity was associated with renal flares in the placebo (HR: 3.7; 95% CI: 2.0-6.9; p< 0.001) but not in the belimumab subgroup, whereas anti-ribosomal P positivity was associated with renal flares in the belimumab subgroup only (HR: 2.8; 95% CI: 1.5-5.0; p= 0.001).

CONCLUSION

A history of renal involvement, high baseline proteinuria, hypoalbuminaemia, and C3 consumption were robust determinants of impending renal flares. Beyond anti-dsDNA, anti-Sm and anti-ribosomal P protein antibody positivity may have value in surveillance of renal SLE.