British Axial Spondyloarthritis Inception Cohort (BAxSIC): a protocol for a multicentre real-world observational cohort study of early axial spondyloarthritis.

Objectives: Timely diagnosis remains a challenge in axial SpA (axSpA). In addition, data are scarce on the impact of diagnostic delay and disease progression in affected individuals. The British Axial Spondyloarthritis Inception Cohort (BAxSIC) study aims to investigate the impact of newly diagnosed axSpA, the natural history of the disease and the effect of diagnostic delay on disease outcomes. Methods: BAxSIC is a prospective, multicentre, observational study. Eligible participants are adults (≥16 years of age), with a physician-confirmed diagnosis of axSpA in the 6 months prior to study entry, recruited from secondary and tertiary rheumatology centres in the UK. Participants will be followed up for 3 years, with in-person visits at baseline and 24 months. In addition, patient self-reported assessments will be recorded remotely via the online electronic case report form (eCRF) at 6, 12, 18, 30 and 36 months. Results: The first patient was enrolled in BAxSIC in June 2023. Recruitment is currently ongoing and is planned to end in June 2026. Initial results will be available in 2027. Since opening, the trial has undergone two protocol amendments. Conclusion: The BAxSIC study is the first inception cohort designed to investigate the impact of diagnostic delay on clinical presentation and long-term functional outcomes in patients with axSpA in the UK. With an innovative, patient-led virtual longitudinal data collection model, data generated from this study will help inform and improve the care of people newly diagnosed with axSpA. Trial registration: ClinicalTrials.gov (http://clinicaltrials.gov), NCT05676775.

Improved physical functioning, sleep, work productivity and overall health-related quality of life with bimekizumab in patients with axial spondyloarthritis: results from two phase 3 studies.

OBJECTIVE: To assess the impact of bimekizumab on physical functioning, sleep, work productivity and overall health-related quality of life (HRQoL) in patients with non-radiographic (nr-) and radiographic (r-) axial spondyloarthritis (axSpA) in the phase 3 studies BE MOBILE 1 and 2. METHODS: Patients were randomised to subcutaneous bimekizumab 160 mg or placebo every 4 weeks; from Week 16, all patients received bimekizumab 160 mg every 4 weeks. We report the following outcomes to Week 52: Bath Ankylosing Spondylitis Functional Index (BASFI), Medical Outcomes Study Sleep Scale Revised (MOS-Sleep-R) Index II, Work Productivity and Activity Impairment: axSpA (WPAI:axSpA), Short Form-36 Physical and Mental Component Summary (SF-36 PCS/MCS) and Ankylosing Spondylitis Quality of Life (ASQoL). RESULTS: At Week 16, bimekizumab-randomised patients demonstrated significantly greater improvement from baseline versus placebo in BASFI, SF-36 PCS and ASQoL (p<0.001), and numerically greater improvements in MOS-Sleep-R Index II and WPAI:axSpA scores. Higher proportions of bimekizumab-randomised versus placebo-randomised patients at Week 16 achieved increasingly stringent thresholds for improvements in BASFI (0 to ≤4), and thresholds for meaningful improvements in SF-36 PCS (≥5-point increase from baseline) and ASQoL (≥4-point decrease from baseline). Responses were sustained or further improved to Week 52, where 60%-70% of bimekizumab-treated patients achieved BASFI ≤4 and meaningful improvements in SF-36 PCS and ASQoL, regardless of whether originally randomised to bimekizumab or placebo. CONCLUSION: Bimekizumab treatment led to early improvements in physical function, sleep, work productivity and overall HRQoL at Week 16 in patients across the full axSpA disease spectrum. Improvements were sustained to Week 52. TRIAL REGISTRATION NUMBERS: NCT03928704; NCT03928743.

Granulocyte-macrophage colony-stimulating factor neutralisation in patients with axial spondyloarthritis in the UK (NAMASTE): a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a proinflammatory cytokine overproduced in several inflammatory and autoimmune diseases, including axial spondyloarthritis. Namilumab is a human IgG1 monoclonal anti-GM-CSF antibody that potently neutralises human GM-CSF. We aimed to assess the efficacy of namilumab in participants with moderate-to-severe active axial spondyloarthritis. METHODS: This proof-of-concept, randomised, double-blind, placebo-controlled, phase 2, Bayesian (NAMASTE) trial was done at nine hospitals in the UK. Participants aged 18-75 years with axial spondyloarthritis, meeting the Assessment in SpondyloArthritis international Society (ASAS) criteria and the ASAS-defined MRI criteria, with active disease as defined by a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), were eligible. Those who had inadequately responded or had intolerance to previous treatment with an anti-TNF agent were included. Participants were randomly assigned (6:1) to receive subcutaneous namilumab 150 mg or placebo at weeks 0, 2, 6, and 10. Participants, site staff (except pharmacy staff), and central study staff were masked to treatment assignment. The primary endpoint was the proportion of participants who had an ASAS ≥20% improvement (ASAS20) clinical response at week 12 in the full analysis set (all randomly assigned participants). This trial is registered with ClinicalTrials.gov (NCT03622658). FINDINGS: From Sept 6, 2018, to July 25, 2019, 60 patients with moderate-to-severe active axial spondyloarthritis were assessed for eligibility and 42 were randomly assigned to receive namilumab (n=36) or placebo (n=six). The mean age of participants was 39·5 years (SD 13·3), 17 were women, 25 were men, 39 were White, and seven had previously received anti-TNF therapy. The primary endpoint was not met. At week 12, the proportion of patients who had an ASAS20 clinical response was lower in the namilumab group (14 of 36) than in the placebo group (three of six; estimated between-group difference 6·8%). The Bayesian posterior probability η was 0·72 (>0·927 suggests high clinical significance). The rates of any treatment-emergent adverse events in the namilumab group were similar to those in the placebo group (31 vs five). INTERPRETATION: Namilumab did not show efficacy compared with placebo in patients with active axial spondyloarthritis, but the treatment was generally well tolerated. FUNDING: Izana Bioscience, NIHR Oxford Biomedical Research Centre (BRC), NIHR Birmingham BRC, and Clinical Research Facility.

Matching-Adjusted Indirect Comparison of the 52-Week Efficacy of Bimekizumab Versus Secukinumab and Ixekizumab for the Treatment of Radiographic Axial Spondyloarthritis.

INTRODUCTION: A previous network meta-analysis established 16-week relative efficacy with bimekizumab, an inhibitor of interleukin (IL)-17F in addition to IL-17A, versus other treatments for patients with radiographic axial spondyloarthritis (r-axSpA; i.e., ankylosing spondylitis), including the IL-17A inhibitors secukinumab and ixekizumab. This matching-adjusted indirect comparison (MAIC) assessed 52-week relative efficacy of bimekizumab versus secukinumab and ixekizumab. METHODS: Individual patient data from BE MOBILE 2 (bimekizumab 160 mg; N = 220) were matched to pooled summary data from MEASURE 1/2/3/4 (secukinumab 150 mg), MEASURE 3 (secukinumab 300 mg; escalated dose for inadequate responders), COAST-V (ixekizumab) and COAST-V/-W (ixekizumab). BE MOBILE 2 patients were reweighted using propensity score weights based on age, sex, ethnicity, tumor necrosis factor inhibitor (TNFi) exposure, weight, baseline ASDAS and BASFI (secukinumab) and baseline BASDAI (ixekizumab), and 52-week efficacy outcomes from the trial recalculated. Odds ratios (OR) or mean difference for unanchored comparisons are reported with 95% confidence intervals (CI). RESULTS: At week 52, MAIC demonstrated that patients may have higher likelihood of improvement in key efficacy outcomes with bimekizumab versus secukinumab 150 mg (e.g., ASAS40: [OR (95% CI): 1.48 (1.05, 2.10); p = 0.026]; effective sample size [ESS] = 177). Differences in 52-week efficacy outcomes between bimekizumab and secukinumab 300 mg dose escalation were non-significant (ESS = 120). Bimekizumab versus ixekizumab 80 mg comparisons (COAST-V only; ESS = 84) also suggested that differences were non-significant for most key efficacy outcomes. Other ixekizumab comparisons (COAST-V/-W; ESS = 45) suggested bimekizumab may have higher comparative efficacy for many of the same efficacy outcomes, however ixekizumab analyses were limited by poor population overlap, likely due to the greater proportion of patients with previous TNFi exposure. CONCLUSIONS: Patients treated with bimekizumab may have a higher likelihood of achieving improved longer-term efficacy versus secukinumab 150 mg, suggesting bimekizumab may be a favorable therapeutic option for r-axSpA. Differences in efficacy outcomes with bimekizumab versus ixekizumab 80 mg were mostly non-significant, depending on the populations considered.