Project description:Systemic lupus erythematosus (SLE) is one of the most challenging autoimmune disorders with a complex pathophysiology and diverse clinical presentation. Many drugs have been used to treat SLE with suboptimal results, especially in patients with moderate-to-severe disease. Belimumab is the first biological drug to be approved for the treatment of SLE in more than 50 years. This monoclonal antibody blocks B-cell activating factor, a cytokine important for B-cell differentiation and survival. In this review we focus on the activity of belimumab in patients with SLE and discuss the controversies of its use.
Project description:Systemic lupus erythematosus (SLE) is a chronic inflammatory disorder that is driven by autoantibodies that target multiple organ systems. B-lymphocyte stimulator (BLyS) and its receptors on B-cell subsets play an important role in autoimmune B-cell development and SLE pathogenesis. Targeted therapy with belimumab, the monoclonal antibody against BLyS, has shown clinical benefit in two large-scale, multicenter phase III trials leading to US Food and Drug Administration approval for patients with serologically positive SLE who have active disease despite standard therapy. This review will discuss the challenges in lupus drug development and clinical trials, the basics of B-cell pathogenesis in SLE, the recent lupus clinical trials of B-cell targeted treatments, and other potential targeted therapies under investigation for patients with lupus.
Project description:The phase 2 placebo-controlled, double-blind PLUTO trial characterized the pharmacokinetics of belimumab plus standard systemic lupus erythematosus (SLE) therapy in patients with childhood-onset SLE (cSLE) and demonstrated similar efficacy and safety to that in adult SLE. Patients with active cSLE aged 5-17 years were randomized to intravenous belimumab 10 mg/kg every 4 weeks (n = 53). A linear 2-compartment population pharmacokinetics (popPK) model with first-order elimination was developed, and an exploratory exposure-response analysis assessed the impact of between-patient exposure variability on clinical response (SLE Responder Index 4 [SRI4]) in week 52, and occurrence of serious adverse events during the study. The popPK model estimated clearance of 158 mL/day, steady-state volume of distribution of 3.5 L, terminal half-life of 16.3 days, and distribution half-life of 0.8 days in the overall population. Fat-free mass (FFM) better characterized the pharmacokinetics than total body weight and was more consistent with allometric scaling theory; belimumab pharmacokinetics were largely determined by FFM. Age, sex, disease activity, and concomitant medication had no impact on pediatric belimumab exposure after accounting for body size. Individual and median steady-state pediatric pharmacokinetic profiles were similar to known adult profiles and pediatric exposure estimates for belimumab 10 mg/kg intravenously were consistent with adult exposures. Exposures were similar between SRI4 responders and nonresponders, and patients who did or did not experience a serious adverse event. There was no clinically relevant correlation between exposure and efficacy or safety, confirming belimumab 10 mg/kg intravenous dose every 4 weeks as appropriate for pediatric patients with cSLE.
Project description:Organ damage is a key determinant of poor long-term prognosis and early death in patients with systemic lupus erythematosus (SLE). Prevention of damage is a key treatment goal of the 2019 update of the European Alliance of Associations for Rheumatology (EULAR) recommendations for SLE management. Belimumab is a monoclonal antibody that inhibits B lymphocyte stimulator (BLyS) and is the only therapy approved for both SLE and lupus nephritis. Here, we review the clinical trial and real-world data on the effects of belimumab on organ damage in adult patients with SLE. Across 4 phase III studies, belimumab in combination with background SLE therapy demonstrated consistent reductions in key drivers of organ damage including disease activity, risk of new severe flares, and glucocorticoid exposure compared to background therapy alone. Long-term belimumab use in SLE also reduced organ damage progression measured by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, as reported in open-label extension studies, and propensity score-matched comparative analyses to background therapy alone. Results from a clinical trial showed that in patients with active lupus nephritis, belimumab treatment improved renal response, reduced the risk of renal-related events, and impacted features related to kidney damage progression compared to background therapy alone. The decrease of organ damage accumulation observed with belimumab treatment in SLE, including lupus nephritis, suggest a disease-modifying effect.
Project description:ObjectiveThis study aimed to evaluate the clinical efficacy of belimumab in patients with early systemic lupus erythematosus (SLE), defined as having a disease duration of less than 6 months.MethodsWe retrospectively identified patients with SLE in the early stage who received belimumab and standard of care (belimumab group) or standard of care alone (control group) since September 2020. Propensity score matching (PSM) was used to reduce potential bias. The primary endpoint was lupus low disease activity status (LLDAS) at weeks 12 and 24. The secondary endpoints were remission and the proportion of glucocorticoid dose tapering to 7.5 mg/day. The efficacy of belimumab in patients with lupus nephritis was also assessed.ResultsOut of 111 eligible patients, 16 patients in the belimumab group and 31 patients in the control group were identified by 1:2 PSM. At week 24, a significantly higher proportion of individuals achieved low disease activity state (LLDAS) in the belimumab group compared to the control group (56.3% vs. 19.4%, OR = 5.357, 95% CI = 1.417 to 20.260, p = 0.013). Furthermore, more patients in the belimumab group were reduced to low-dose glucocorticoid ( ≤ 7.5 mg/day) at week 24 (75.0% vs. 35.5%, OR = 5.182, 95%CI = 1.339 to 20.058, p = 0.017). Significant improvements in Patient Global Assessment scores were observed at Week 12 and 24 for those treated with belimumab compared to controls. In a subgroup analysis evaluating the efficacy of belimumab in patients with lupus nephritis, 42.9% of the seven individuals treated with belimumab achieved a complete renal response (CRR) by Week 24, and no instances of disease relapse were observed.ConclusionsIn SLE patients with a disease duration of less than 6 months, belimumab treatment can promote LLDAS achievement and reduce glucocorticoid dose, leading to a better prognosis. Introducing belimumab in the early stage of SLE may be a beneficial decision.
Project description:Background and objectiveIntravenous (IV) belimumab is the first treatment approved for children ≥5 years of age with active autoantibody-positive systemic lupus erythematosus (SLE) in the USA, Europe, and Japan. Pharmacokinetic data for belimumab were collected from several clinical trials in Chinese and non-Chinese adults and non-Chinese pediatric patients with SLE. This study aimed to predict the belimumab dose-exposure relationship to Chinese pediatric patients with SLE, as part of the belimumab registration process for this population in China, using a population PK modeling approach.MethodsAn initial linear two-compartment population pharmacokinetic model was built using data from adults only, and considering and adjusting for the covariates age, body weight, body mass index, fat-free mass, race, baseline albumin and immunoglobulin G levels. The model was used to study possible ethnic differences between Chinese and non-Chinese adults and to predict pediatric pharmacokinetic data in a study of non-Chinese pediatric patients (PLUTO study; NCT01649765). The predicted data were compared with the observed data from PLUTO. The model was then updated with pediatric data from PLUTO to predict steady-state belimumab exposure in Chinese pediatric patients with SLE receiving belimumab 10 mg/kg IV every 4 weeks.ResultsThe dataset comprised 9650 sampled concentration values from 1783 patients. The pharmacokinetics of belimumab were adequately described by the final model using all adult and pediatric data with the estimated typical clearance of 238 ml/day in adult and pediatric patients and steady-state volume of distribution of 4915 ml in adults. Between-patient variability was modest (coefficients of variation: 26.1% for clearance; 8.9% and 28.5%, respectively, for volumes of distribution of the central and peripheral compartments). Six covariates were identified that influenced pharmacokinetics: age, fat-free mass, an indicator of North East Asian race, baseline albumin, immunoglobulin G, and an early study indicator (two early phase I and phase II belimumab studies: LBSL01 and LBSL02). The analysis showed no apparent difference in steady-state exposure between Chinese and non-Chinese populations and between pediatric and adult populations receiving belimumab 10 mg/kg IV.ConclusionsIn Chinese pediatric patients with SLE, belimumab 10 mg/kg IV every 4 weeks is expected to have exposure similar to that in Chinese adults and non-Chinese pediatric patients with SLE, supporting the use of this regimen in Chinese pediatric patients with SLE.Clinical trial registration numbersNCT01649765, NCT00657007, NCT00071487, NCT01345253, NCT01516450, NCT00410384, NCT00424476, NCT02880852, NCT01583530.
Project description:Systemic lupus erythematosus (SLE) is a complex autoimmune rheumatic disease with multiple presentations, whose management presents many challenges. Many disease modifying or immunosuppressive drugs have been used with limited success, especially in patients with more severe disease activity. Belimumab is the first drug to be approved specifically for the treatment of SLE in more than 50 years. By blocking the B-cell activating factor, it interferes in B-cell differentiation and survival. Here we consider the results of the clinical trials that led to its approval, as well as the post-hoc analyses, follow-up studies and the current trials.
Project description:IntroductionBelimumab is a recombinant human monoclonal antibody that binds to soluble B-lymphocyte stimulator and inhibits its biological activity. Since receiving approvals for the treatment of systemic lupus erythematosus (SLE), several observational studies have investigated the effectiveness of belimumab in the real-world setting. This study reports a systematic review and meta-analysis of the literature to evaluate the real-world effectiveness of belimumab for the treatment of SLE.MethodsA literature search following PRISMA Guidelines and limited to studies in English was performed (2014-2020) to identify relevant studies reporting effectiveness outcomes of belimumab in patients with SLE. A modified version of the Newcastle-Ottawa Scale was used to assess study quality. Outcomes, including SLE Disease Activity Index (SLEDAI) score, prednisone-equivalent use, and SLE flare were pooled and analyzed using statistical aggregation methods.ResultsThe literature search identified 514 articles for initial review. Of these, 17 articles were suitable for data extraction and summary. Baseline characteristics of patients in real-world studies were generally similar to those of relevant clinical trials, including age, sex, disease duration, SLEDAI score, and prednisone-equivalent use. Real-world use of belimumab was associated with reductions in SLEDAI score (mean baseline score to month 6: 10.1-4.4; 57% reduction), prednisone-equivalent dosing (mean baseline dose to month 6: 12.1 mg/day to 6.9 mg/day; 43% reduction), and flare frequency (12 months prior to belimumab to 12 months after belimumab: 1.15-0.39 mean flares per patient per year; 66% reduction). Long-term data (up to 2 years post-treatment initiation) for SLEDAI score and prednisone-equivalent dose indicated that improvements in both outcomes continue over time among patients remaining on therapy.ConclusionsIn the real-world setting, observed outcomes with belimumab for the treatment of SLE are consistent with those reported from randomized clinical trials. Improvements persist long-term for SLEDAI activity and prednisone-equivalent use with belimumab.
Project description:AimsThe pharmacokinetics (PK) of belimumab, a human immunoglobulin G1λ (IgG1λ) monoclonal antibody treatment for systemic lupus erythematosus (SLE), have been well reported. Clinical PK data in healthy participants and patients with SLE from Mainland China suggest lower-than-expected belimumab exposure. This study assessed inter-regional differences in belimumab exposure and efficacy via the exposure-response relationship to inform any dose-adjustment requirements.MethodsData from nine interventional belimumab studies in healthy participants and patients with SLE were used to update two-compartment PK models with first-order subcutaneous (SC) absorption, and a logistic regression model characterizing the 52-week SLE Responder Index (SRI) response in adult and paediatric patients with SLE. Covariates of belimumab PK and efficacy were identified using forward selection (P > .05) and backward elimination (P < .01). The models were evaluated using statistical tests and visual predictive checks.ResultsBaseline fat-free mass was the most significant covariate affecting belimumab PK; baseline albumin and IgG concentrations were also PK covariates. After adjusting for covariates, Mainland Chinese patients had significantly higher observed belimumab clearance (28%) and central volume of distribution (20%) than other populations, leading to lower-than-expected exposures. Despite this, following the same dose, they were expected to have almost identical SRI response rates vs. other populations from the exposure-response analysis.ConclusionsBelimumab 10 mg kg-1 intravenously every 4 weeks, or 200 mg SC every week, would achieve the maximum treatment effect for North East Asian patients with SLE (including Mainland Chinese) and similar responses to patients from other regions, despite lower reported exposures in Chinese patients.
Project description:ObjectivesAutoreactive memory B cells (MBCs) contribute to chronic and progressive courses in autoimmune diseases like SLE. The efficacy of belimumab (BEL), the first approved biologic treatment for SLE and LN, is generally attributed to depletion of activated naïve B cells and inhibition of B-cell activation. BEL's effect on MBCs is currently unexplained. We performed an in-depth cellular and transcriptomic analysis of BEL's impact on the blood MBC compartment in patients with SLE.MethodsA retrospective meta-analysis was conducted, pooling flow cytometry data from four randomized trials involving 1245 patients with SLE treated with intravenous BEL or placebo. Then, extensive MBC phenotyping was performed using high-sensitivity flow cytometry in patients with mild/moderate SLE and severe SLE/LN treated with subcutaneous BEL. Finally, transcriptomic characterization of surging MBCs was performed by single-cell RNA sequencing.ResultsIn BEL-treated patients, a significant increase in circulating MBCs, in a broad range of MBC subsets, was established at week 2, gradually returning to baseline by week 52. The increase was most prominent in patients with higher SLE disease activity, serologically active patients and patients aged ≤18 years. MBCs had a non-proliferating phenotype with a prominent decrease in activation status and downregulation of numerous migration genes.ConclusionUpon BEL initiation, an increase of MBCs was firmly established. In the small cohort investigated, circulating MBCs were de-activated, non-proliferative and demonstrated characteristics of disrupted lymphocyte trafficking, expanding on our understanding of the therapeutic mechanism of B-cell-activating factor inhibition by BEL.Trial registrationClinicalTrials.gov, http://clinicaltrials.gov, NCT00071487, NCT00410384, NCT01632241, NCT01649765, NCT03312907, NCT03747159.