Disrupting B and T-cell collaboration in autoimmune disease: T-cell engagers versus CAR T-cell therapy?

B and T cells collaborate to drive autoimmune disease (AID). Historically, B- and T-cell (B-T cell) co-interaction was targeted through different pathways such as alemtuzumab, abatacept, and dapirolizumab with variable impact on B-cell depletion (BCD), whereas the majority of patients with AID including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and organ transplantation benefit from targeted BCD with anti-CD20 monoclonal antibodies such as rituximab, ocrelizumab, or ofatumumab. Refractory AID is a significant problem for patients with incomplete BCD with a greater frequency of IgD-CD27+ switched memory B cells, CD19+CD20- B cells, and plasma cells that are not directly targeted by anti-CD20 antibodies, whereas most lymphoid tissue plasma cells express CD19. Furthermore, B-T-cell collaboration is predominant in lymphoid tissues and at sites of inflammation such as the joint and kidney, where BCD may be inefficient, due to limited access to key effector cells. In the treatment of cancer, chimeric antigen receptor (CAR) T-cell therapy and T-cell engagers (TCE) that recruit T cells to induce B-cell cytotoxicity have delivered promising results for anti-CD19 CAR T-cell therapies, the CD19 TCE blinatumomab and CD20 TCE such as mosunetuzumab, glofitamab, or epcoritamab. Limited evidence suggests that anti-CD19 CAR T-cell therapy may be effective in managing refractory AID whereas we await evaluation of TCE for use in non-oncological indications. Therefore, here, we discuss the potential mechanistic advantages of novel therapies that rely on T cells as effector cells to disrupt B-T-cell collaboration toward overcoming rituximab-resistant AID.

Concomitant Sjögren's disease as a biomarker for treatment effectiveness in rheumatoid arthritis - results from the Swiss clinical quality management cohort.

OBJECTIVE: To investigate the clinical phenotype and treatment response in patients with rheumatoid arthritis (RA) with and without concomitant Sjögren's disease (SjD). METHODS: In this observational cohort study, patients with RA from the Swiss Clinical Quality Management in Rheumatic Diseases registry were categorised according to the presence or absence of SjD. To assess treatment effectiveness, drug retention of tumor necrosis factor-α-inhibitors (TNFi) was compared to other mode of action (OMA) biologics and Janus kinase-inhibitors (JAKi) in RA patients with and without SjD. Adjusted hazard ratios (HR) for time to drug discontinuation were compared in crude and adjusted Cox proportional regression models for potential confounders. RESULTS: We identified 5974 patients without and 337 patients with concomitant SjD. Patients with SjD were more likely to be female, to have a positive rheumatoid factor, higher disease activity scores, and erosive bone damage. For treatment response, a total of 6781 treatment courses were analysed. After one year, patients with concomitant SjD were less likely to reach DAS28 remission with all three treatment modalities. Patients with concomitant SjD had a higher hazard for stopping TNFi treatment (adjusted HR 1.3 [95% CI 1.07-1.6]; OMA HR 1.12 [0.91-1.37]; JAKi HR 0.97 [0.62-1.53]). When compared to TNFi, patients with concomitant SjD had a significantly lower hazard for stopping treatment with OMA (adjusted HR 0.62 [95% CI 0.46-0.84]) and JAKi (HR 0.52 [0.28-0.96]). CONCLUSION: RA patients with concomitant SjD reveal a severe RA phenotype, are less responsive to treatment, and more likely to fail TNFi.

The impact of concomitant Sjögren's disease on rheumatoid arthritis disease activity: a systematic review and meta-analysis.

OBJECTIVES: Rheumatoid arthritis (RA) and Sjögren's syndrome (SS) frequently co-exist but the consequence for RA disease activity of having concomitant SS (RA/SS) is not well established. We conducted a systematic review and meta-analysis to investigate the impact of SS on disease outcomes in individuals with RA. METHODS: We searched Web of Science (Core Collection, FSTA, Medline), PubMed and Cochrane databases, without language restriction. Studies reporting RA disease activity scores, joint counts, visual analogue scales (VAS), disability and joint damage, and comparing RA and RA/SS were selected. Outcomes reported in at least 3 studies in which the diagnosis of SS fulfilled classification criteria underwent meta-analysis, using a random effects model where heterogeneity was detected. RESULTS: The literature search identified 2991 articles and abstracts; 23 underwent full-text review and 16 were included. The studies included a total of 29722 patients (8614 with RA/SS and 21108 with RA). Using studies eligible for meta-analysis (744 patients with RA/SS and 4450 with RA), we found higher DAS-28 ESR scores (mean difference 0.50, 95% CI -0.008-1.006; p=0.05), higher swollen joint count scores (mean difference 1.05, 95% CI 0.42-1.67; p=0.001), and greater functional disability as measured by HAQ (mean difference 0.19, 95% CI 0.05-0.34; p=0.009) in RA/SS compared to RA alone. Other outcome measures (tender joint count, fatigue VAS) showed a numerical trend towards higher scores in RA/SS but were not statistically significant. CONCLUSIONS: RA/SS patients appear to have higher disease activity and more functional disability than patients with RA alone. The aetiology and clinical implications of this are unclear and warrant further investigation.

Tocilizumab monotherapy after ultra-short glucocorticoid administration in giant cell arteritis: a single-arm, open-label, proof-of-concept study.

BACKGROUND: Two randomised controlled trials showed a glucocorticoid-sparing effect of tocilizumab in patients with giant cell arteritis. In the GUSTO trial we aimed to evaluate the efficacy and safety of tocilizumab monotherapy after ultra-short-term glucocorticoid treatment in patients with new-onset giant cell arteritis. METHODS: This investigator-initiated, single-arm, single-centre, open-label, proof-of-concept trial with a Simon's two stage design was done at University Hospital Bern, Bern, Switzerland. We enrolled patients aged older than 50 years newly diagnosed with giant cell arteritis (within 4 weeks before the screening visit) satisfying the American College of Rheumatology criteria or with large vessel vasculitis-associated polymyalgia rheumatica. The participants received 500 mg methylprednisolone intravenously for 3 consecutive days. Thereafter, glucocorticoid treatment was discontinued and a single infusion of tocilizumab (8 mg/kg bodyweight) was administered intravenously, followed by weekly subcutaneous tocilizumab injections (162 mg) until week 52. The primary endpoint was the proportion of patients who had remission within 31 days and showed no relapse at week 24. The secondary endpoints were the proportion of patients with complete relapse-free remission of disease at weeks 24 and 52, and time to first remission, first relapse (after induction of remission), and first partial remission. This study is registered with ClinicalTrials.gov, NCT03745586. FINDINGS: From Nov 23, 2018, to Sept 22, 2019, 18 patients were enrolled (12 of 18 were female, 18 of 18 were White) with a median age of 72 (IQR 67-75) years. Overall, 15 of 18 patients had cranial symptoms, ten of 18 had polymyalgia rheumatica symptoms, and 13 of 18 showed a positive histopathology. At the interim analysis, three (25%) of 12 patients were in remission. The null hypothesis could not be rejected, and the study was futile with respect to the primary endpoint. However, 14 (78%) of 18 patients had remission within 24 weeks (mean time to first remission 11·1 weeks, 95% CI 8·3-13·9) and 13 of 18 showed no relapses up to 52 weeks (72%, 47-90). Mean time to first partial remission was 6·2 [3·7-8·7] weeks. Time to first relapse (after induction of remission) could not be estimated as there was no relapse after induction of remission. Overall, three of 18 patients did not respond to treatment and two of 18 discontinued the study due to an adverse event (hepatopathy [one] and diverticulitis [one]). Anterior ischaemic optic neuropathy occurred in one patient. INTERPRETATION: The data show a slow remission-inducing and a lasting remission-maintaining effect of tocilizumab after an ultra-short pulse of glucocorticoids in patients with newly diagnosed giant cell arteritis. As a proof-of-concept study, our data do not allow us to propose clinical recommendations. FUNDING: Bern University Hospital, University of Bern, and F Hoffmann-La Roche.