Irrespective of the Number of Erosions at Baseline, Patients with Psoriatic Arthritis Treated with Ixekizumab Show Improved Clinical Outcomes

M. Elaine Husni¹, Vinod Chandran², Jeffrey Lisse³, Rebecca Bolce³, Carlos Diaz³, Baojin Zhu³, Elaine Lui⁴ and Laura Coates⁵, ¹Cleveland Clinic / Department of Rheumatic and Immunologic Diseases, Cleveland, OH, ²Schroeder Arthritis Institute, Krembil Research Institute, University Health Network and Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, ON, Canada, ³Eli Lilly and Company, Indianapolis, IN, ⁴Brightech International, An Everest Clinical Research Company, Somerset, NJ, ⁵University of Oxford, Oxford, United Kingdom

Meeting: ACR Convergence 2023

Keywords: Biologicals, clinical trial, Erosions, immunology, Psoriatic arthritis

Session Information

Date: Tuesday, November 14, 2023

Title: (2227–2256) Spondyloarthritis Including Psoriatic Arthritis – Treatment: SpA Poster III

Session Type: Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose: Psoriatic arthritis (PsA) is a chronic and progressive disease characterized by high rates of early joint erosions, which have been associated with impaired quality of life and increased mortality rates^1,2. However, the relationship between the number of erosions at baseline (BL) and response to biological disease-modifying antirheumatic drugs (bDMARD) therapy has not been thoroughly investigated. In this post-hoc analysis, we assessed the efficacy of placebo (PBO), ixekizumab (IXE) or adalimumab (ADA) on patients (pts) with erosions visible on hand radiographs at BL.

Methods: Biologic-naïve pts with PsA (SPIRIT-P1, NCT01695239) were randomly assigned to PBO, IXE 80-mg every 2 weeks (Q2W) or 4 weeks (Q4W) after a 160-mg starting dose, or ADA 40-mg Q2W. Pts were stratified into two groups based on the number of BL erosions (erosion component of the modified total sharp scores ≤4 and >4). At week 24, outcomes analyzed for different baseline erosion score (BES) groups included American College of Rheumatology (ACR) 20%, 50%, 70%, Disease Activity index for PSoriatic Arthritis-Low Disease Activity (DAPSA-LDA), Health Assessment Questionnaire-Disability Index (HAQ-DI) and Minimal Disease Activity-Psoriasis Area Severity Index (MDA-PASI). Missing data were imputed using non-responder imputation (NRI) for categorical, and modified baseline observation carried forward (mBOCF) for continuous outcome variables. Comparisons between PBO and treatment within each BES group used logistic models for categorical, and ANCOVA for continuous outcome variables, adjusting for BL values, disease duration, geographic region, and prior conventional DMARD (cDMARD) experience.

Results: 183 pts with BES≤4 and 205 pts with BES >4 at BL were included. At week 24, pts with BES >4 on PBO had worse outcomes across all parameters compared to those with BES≤4. There was significant improvement in DAPSA-LDA response rates in pts treated with IXE regardless of BES, whereas significant response rates were seen in ADA treated pts with BES >4 (Figure 1a). MDA-PASI response rates were significant in patients treated with IXEQ2W and IXEQ4W who had BES≤4, whereas pts with BES >4 demonstrated a significant response rate with IXEQ2W and ADA (Figure 1b). Change from baseline in HAQ-DI was significant for all pts treated with bDMARDS, regardless of BES (Figure 1c). Similarly, regardless of BES, significant differences in ACR50 and ACR70 response rates versus PBO were seen for pts treated with bMDARDS (Figure 2b and 2c).

Conclusion: Pts with higher BES in the PBO group experienced worse outcomes. Higher response rates (e.g., ACR50/70) were also harder to achieve in pts with higher BES. Irrespective of BES, IXE treated pts showed greater improvement compared to PBO in the achievement of LDA and functional outcomes.

References:
Touma, Z., et al. J. of Rheumatology. 2016; 43(6)
Gladman, D. D. et al. Arthritis & Rheumatism. 1998; 41(6)

Data are mean(±SD) unless otherwise stated. Abbreviations: PBO=placebo, ADA=adalimumab, IXE=ixekizumab, Q2W=every 2 weeks, Q4W=every 4 weeks, yrs=years, N=number of responders, n=number of patients in specified category, PsA=psoriatic arthritis, BL=baseline, DAPSA=Disease Activity index for PSoriatic Arthritis, PASI= Psoriasis Area Severity Index, BES=Baseline Erosion Score, HAQ-DI= Health Assessment Questionnaire-Disability Index.

a) DAPSA-LDA Response Rate (%), NRI, b) MDA-PASI Response Rate (%), NRI and c) HAQ-DI Change from Baseline (mBOCF) at Week 24. Significantly greater response versus PBO denoted by * (p≤0.05), ** (p≤0.01), *** (p≤0.001). Abbreviations: PBO=placebo, ADA=adalimumab, IXE=ixekizumab, Q2W=every 2 weeks, Q4W=every 4 weeks, NRI=non-responder imputation, DAPSA-LDA= Disease Activity index for PSoriatic Arthritis-Low Disease Activity, MDA-PASI= Minimal Disease Activity-Psoriasis Area Severity Index, BES=Baseline Erosion Score, LSM= Least-squares Means, mBOCF= modified Baseline Observation Carried Forward, HAQ-DI= Health Assessment Questionnaire-Disability Index.

a) ACR 20, b) ACR 50, c) ACR70 Response Rate (%), NRI at Week 24. Significantly greater response versus PBO denoted by * (p≤0.05), ** (p≤0.01), *** (p≤0.001). Abbreviations: PBO=placebo, ADA=adalimumab, IXE=ixekizumab, Q2W=every 2 weeks, Q4W=every 4 weeks, NRI=non-responder imputation, ACR=American College of Rheumatology, BES=Baseline Erosion Score.

Disclosures: M. Husni: AbbVie, 1, 2, Amgen, 1, 2, Bristol-Myers Squibb, 1, 2, Eli Lilly, 1, 2, Janssen, 1, 2, Novartis, 1, 2, Pfizer, 1, 2, UCB, 1, 2; V. Chandran: AbbVie, 1, 5, 6, Amgen, 1, 5, 6, AstraZeneca, 3, Bristol-Myers Squibb (BMS), 1, 6, Eli Lilly, 1, 5, 6, Janssen, 1, 6, Novartis, 1, 1, 6, UCB, 1, 2; J. Lisse: Eli Lilly and Company, 3, 11; R. Bolce: Eli Lilly and Company, 3, 11; C. Diaz: Eli Lilly and Company, 3, 11; B. Zhu: Eli Lilly and Company, 3, 11; E. Lui: None; L. Coates: AbbVie, 2, 5, 6, Amgen, 2, 5, 6, Biogen, 6, Bristol Myers Squibb, 2, Celgene, 2, 5, 6, Eli Lilly, 2, 5, 6, Galapagos, 2, 6, Gilead Sciences, 2, 6, GSK, 6, Janssen, 2, 5, 6, Medac, 6, MoonLake, 2, Novartis, 2, 5, 6, Pfizer Inc, 2, 5, 6, UCB, 2, 5, 6.

To cite this abstract in AMA style:

Husni M, Chandran V, Lisse J, Bolce R, Diaz C, Zhu B, Lui E, Coates L. Irrespective of the Number of Erosions at Baseline, Patients with Psoriatic Arthritis Treated with Ixekizumab Show Improved Clinical Outcomes [abstract]. Arthritis Rheumatol. 2023; 75 (suppl 9). https://acrabstracts.org/abstract/irrespective-of-the-number-of-erosions-at-baseline-patients-with-psoriatic-arthritis-treated-with-ixekizumab-show-improved-clinical-outcomes/. Accessed .

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