Association of autoantibodies with the IFN signature and NETosis in patients with systemic lupus erythematosus

Mechanistic Evaluation of Anti-CD19 CAR-T Cell Therapy Repurposed in Systemic Lupus Erythematosus Using a Quantitative Systems Pharmacology Model

CAR-T cell therapy, renowned for its success in oncology, is now venturing into the realm of B cell-mediated autoimmune diseases. Recent observations have revealed significant pharmacological effects of CD19 CAR-T cells in patients with systemic lupus erythematosus (SLE), suggesting promising applications in other autoimmune conditions. Consequently, as of December 2024, there are 116 different clinical trials evaluating CAR-T cells against autoimmune conditions. While the field is starting to understand the overall pharmacological actions of CAR-T cells in autoimmune diseases, the dose-exposure-response relationship remains inadequately characterized due to limited clinical data. To address these uncertainties, we have developed a Quantitative Systems Pharmacology (QSP) model using short-term limited clinical data of anti-CD19 CAR-Ts in autoimmune disease patients (n = 5), followed by a model qualification step utilizing an external dataset (n = 13). The developed QSP model integrated and effectively characterized the (1) cellular kinetics of different immunophenotypic population of CAR-T cells, (2) impact of lymphodepletion chemotherapy on host immune cells, (3) CAR-mediated elimination of CD19+ B-cells and (4) dynamic changes in disease surrogate biomarkers and its relationship with clinical score. The key pharmacological biomarkers which were incorporated within the QSP model included anti double stranded DNA (anti-dsDNA) antibodies, proteinuria, C3 protein and IFN-alpha. Later, a linear regression analysis-based relationship was developed between continuous disease biomarkers and the categorical SLE disease activity index (SLE-DAI) determined by the investigators offering a predictive framework for disease progression in SLE patients. This proposed QSP model holds potential to elucidate quantitative pharmacology and expedite clinical advancement of autologous and allogeneic cell therapies in autoimmune diseases.

Type I interferon-stimulated genes predict clinical response to belimumab in systemic lupus erythematosus

The type I interferon (IFN-I) response is crucial in systemic lupus erythematosus (SLE). The mRNA level of interferon-stimulated genes (ISGs) is widely used for evaluating the activity of IFN in SLE. However, the character of ISGs in belimumab-treated SLE patients has not be reported. In this study, we enrolled 53 SLE patients undergoing belimumab treatment and assessed their clinical responses at 3, 6, and 12 months. The expression levels of 25 ISGs in Peripheral blood mononuclear cells (PBMCs) were quantified at baseline and at 3 months using quantitative real-time PCR. Using Least absolute shrinkage and selection operator (LASSO)-logistic regression, five genes (CXCL10, EPSTI1, HECR6, IFI27, IFIH1) were identified to predict belimumab efficacy. The IFN signature score, a multivariate logistic regression model based on the change rates of these genes, positively predicted the SLE responder index (SRI) at 12 months, with an area under curve of 0.940 in receiver operating characteristic and favorable outcomes in decision curve analysis. Patients with an IFN signature score ≥0 had higher SRI response rates, better clinical markers (including SLE disease activity index 2000 scores, anti-dsDNA, IgG levels, daily doses of prednisone, and higher complement C3 and C4 levels), and faster B cell decline than those with scores <0. In conclusion, after 3 months of belimumab treatment, the expression levels of IFN-I-inducible genes varied, and the IFN signature score reliably forecasted the SRI response at 6 and 12 months.