A real-world study confirms that belimumab is effective as add-on therapy in patients with lupus nephritis (LN). Higher baseline proteinuria, however, may hinder response to the monoclonal antibody.
In the BElimumab in Real LIfe Setting Study (BeRLiSS), investigators assessed 91 patients with LN from routine clinical practice settings who received monthly intravenous belimumab (10 mg/kg). Of these, 64 patients (70.3%) achieved the primary efficacy renal response (PERR), defined as proteinuria of 0.7 g/24 h or less and an estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73 m2 or more without the help of rescue therapy, Mariele Gatto, MD, of the University of Padova in Padova, Italy, and colleagues reported in the Journal of Autoimmunity. Further, 35 (38.4%) of those who achieved PERR had a complete renal response, defined as proteinuria of less than 0.5 g/24 h and an eGFR of 90 mL/min/1.73 m2 or higher. Among patients with baseline proteinuria of 1 g/d or more, PERR was achieved by 54% and complete renal response by 19% at 24 months.
A total of 86.7% of patients achieving PERR at 6 months maintained their response over a median 22 months of follow-up, demonstrating belimumab’s durability, the investigators highlighted. Among responders, 7.8% experienced a renal flare.
Belimumab was approved by the FDA for the treatment of active LN in December 2020 based on data from the Belimumab International Study in Lupus Nephritis (BLISS-LN). Results from BeRLiSS support the biologic’s efficacy in LN. Unlike in the clinical trial, belimumab was initial LN treatment in BeRLiSS.
According to Dr Gatto’s team, “belimumab is an effective and safe therapeutic option for patients with LN in daily practice.”
The investigators identified possible predictors of response. On multivariable analysis, arterial hypertension, high serum creatinine, and high proteinuria at baseline were significantly associated with 72%, 3%, and 63% decreased odds of achieving PERR. Anti-Sm positivity was significantly associated with 19.8-fold increased odds of maintaining PERR at 24 months. Achievement of PERR at 6 months was significantly associated with 14.4- and 11.7-fold increased odds of maintaining PERR at 12 and 24 months, respectively. Anti-Sm positivity may be a marker in patients with higher B cell-mediated activation, who are more likely to respond to belimumab, the investigators suggested.
A third of patients stopped taking belimumab, most commonly for inadequate response, adverse events, and pregnancy. Having proteinuria exceeding 2 g/d at baseline was significantly associated with 5.1-fold increased odds of discontinuation. Conversely, class 4 LN was significantly associated with 87% decreased odds of discontinuation.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Gatto M, Saccon F, Andreoli L, et al. Durable renal response and safety with add-on belimumab in patients with lupus nephritis in real-life setting (BeRLiSS-LN): results from a large, nationwide, multicentric cohort. J Autoimmun. Published online September 30, 2021. doi:10.1016/j.jaut.2021.102729