OP0061 A Delphi exercise informing the development of criteria to measure response to treatment in giant cell arteritis

Background: The therapeutic landscape of giant cell arteritis (GCA) is growing rapidly but there are currently no internationally standardized criteria for assessing response to treatment in GCA. To address this gap, an international task force is working to develop such criteria. This project receives support from the European Alliance of Associations for Rheumatology (EULAR) and the American College of Rheumatology (ACR). Following a systematic literature review (SLR),[1] a Delphi exercise was conducted to determine items that might be included in the future response criteria. Objectives: To identify, through a Delphi exercise, the most important and relevant items to consider when developing criteria to measure response to treatment in GCA. Methods: A four-round web-based Delphi exercise was conducted. Participants from 38 countries included patients with GCA and physicians with expertise in GCA. Participants were asked to rate the importance (scale from 1-9; 1 = lowest and 9 = highest importance) of each of the 51 items identified from the SLR [1], grouped in six domains, and propose additional items they considered important to include. Items obtaining a score of 7-9 by at least 70% of physicians and 70% of patients were considered critically important and reached consensus. Items which scored 1-3 by 70% of physicians and patients were considered not important and excluded from subsequent rounds. In a ranking round (4th round), participants selected and ranked the 10 most relevant items from those deemed most important in the previous three rounds. Subsequently, a task force meeting was held where the results of the Delphi and ranking exercise were discussed, and items were selected for inclusion in the next phase of this project. Results: A total of 187 physicians and 85 patients participated in 4 rounds of the Delphi exercise. Of the task force members, 24/32 (75%) participated in the virtual task force meeting. Thirteen new items were proposed in round 1. Twenty-four items were rated as critically important (18 in round 1, 5 in round 2, 1 in round 3) by ≥70% of patients and ≥70% of physicians (Figure 1). These items covered the six domains of the Delphi (Figure 1): 10 for clinical, 2 for laboratory, 5 for imaging, 3 for treatment, 1 for patient-reported outcomes and 3 for damage. No items were excluded during any round, and consensus was not reached for 40 items. The top three highest-rated items by both patients and physicians were headache (ranked highest by 52% of patients and physicians), amaurosis fugax (ranked highest by 10%), and jaw claudication (ranked highest by 7%). Among the items discussed by the task force (Figure 1), glucocorticoid-related parameters were excluded as they were considered indirect indicators of response to treatment. Constitutional symptoms were added by the task force as they are important constellation of symptoms seen in GCA. The task force also decided to cluster items with similar constructs to capture the spectrum of the disease more concisely. For example, “GCA-related ischemic damage” was defined as capturing the spectrum of damage caused by GCA (e.g.: stroke, vision loss, scalp necrosis). 12 items were selected for the next phase of the project (Figure 2). Conclusion: This Delphi exercise identified the items and domains that experts and patients consider important and highly relevant for measuring response to treatment in GCA. These 12 items will be used in a subsequent group conjoint analysis to further prioritize and weigh potential items for inclusion in a draft set of criteria to measure treatment response in GCA. Figure 1 24 items regarding response to treatment in giant cell arteritis that reached consensus after 3 Delphi rounds. Figure 2 The 12 items selected for the next step in developing criteria for response in giant cell arteritis: preliminary criteria and item weighting. GCA: giant cell arteritis. *Item selected by the task force, despite not reaching consensus in the Delphi exercise. REFERENCES: [1] Sanchez-Alvarez C et al. RMD Open 2023;9(2). Acknowledgements: NIL. Disclosure of Interests: Medha Soowamber AbbVie, AbbVie, Otsuka, Milena Bond Consultancy fees from Abbvie, Catalina Sanchez Alvarez: None declared, Carol Langford Grant support from Bristol-Myers Squibb, GlaxoSmithKline, AstraZeneca, Sibel Aydin Abbvie, Pfizer, Janssen, UCB, Novartis, Fresenius Kabi, Abbvie, Pfizer, Janssen, UCB, Eli Lilly, Novartis, Abbvie, Pfizer, Janssen, UCB, Eli Lilly, Novartis, Frank Buttgereit Abbvie, Grünenthal, Horizon Therapeutics, Novartis, Pfizer, Sanofi, Sparrow, Novartis, Abbvie, Sanofi, Abbvie, Almirall, Alexion, Amgen, Biogen, BMS, GSK, Hexal, Horizon Therapeutics, Lilly, Medac, Mundipharma, Novartis, Pfizer, Dario Camellino Astra-Zeneca, Boehringer Ingelheim, GSK, Janssen, Astra-Zeneca, Boehringer Ingelheim, GSK, Janssen, Maria C. Cid GSK, CSL-Vifor, AbbVie, Alexion, Boehringer-Ingelheim, AbbVie, GSK, CSL-Vifor, AstraZeneca, Novartis, Royalty Pharma, Kiniksa Pharmaceuticals LTd, Peter Grayson: None declared, Bernhard Hellmich Abbvie, Novartis, Abbvie, Novartis, Tanaz Kermani: None declared, Nader Khalidi Otsuka, GSK, Mallinckrodt, Roche, AbbVie, BMS, AbbVie, Sanofi, NS Pharma, Sarah Mackie Roche/Chugai, Vifor, Pfizer, UCB, Novartis, Fresenius Kabi and AbbVie, Roche/Chugai, Sanofi, AbbVie, AstraZeneca, Pfizer; Investigator on clinical trials for Sanofi, GSK, Sparrow, Alfred Mahr: None declared, Eric Matteson Boehringer Ingelheim, GmBH, Horizon Therapeutics, Amgen, Mehrdad Maz: None declared, Peter A Merkel AbbVie, Alpine, Amgen, ArGenx, AstraZeneca, Boeringher-Ingelheim, Bristol-Myers Squibb, CSL Behring, GlaxoSmithKline, HiBio, iCell, InflaRx, Janssen, Kinevant, Kyverna, Metagenomia, Novartis, NS Pharma, Q32, Regeneron, Sanofi, Sparrow, Takeda, Vistera, AbbVie, Amgen, AstraZeneca, Boeringher-Ingelheim, Bristol-Myers Squibb, Eicos, Electra, Forbius, Genentech/Roche, GlaxoSmithKline, InflaRx, Neutrolis, Takeda: Payments made to institution, Paul A Monach Boeringer-Ingelheim, Lorna Neill: None declared, Cristina Ponte Abbvie, GSK, Novartis, CSL Vifor, AstraZeneca, Abbvie, GSK, CSL Vifor, Roche, Carlo Salvarani Lilly, Abbvie, Johnson and Johnson, GSK, Novartis, CSL-Vifor, Boehringer-Ingelheim, Wolfgang Schmidt: None declared, Peter Villiger Roche, MSD, GSK, Vifor, AstraZeneca, Roche, Kenneth J Warrington Amgen, Amgen, Sanofi, Kiniksa, Eli Lilly, BMS: Clinical trial support to Mayo Clinic, Christian Dejaco Abbvie, Eli Lilly, Janssen, Galapagos, Novartis, Pfizer, Sparrow, Roche and Sanofi, Abbvie, Eli Lilly, Janssen, Galapagos, Novartis, Pfizer, Sparrow, Roche and Sanofi, AbbVie, Novartis, Sofia Ramiro AbbVie, Eli Lilly, Galapagos/Alfasigma, MSD, Novartis, Pfizer, UCB, Sanofi, AbbVie, Eli Lilly, Galapagos/Alfasigma, MSD, Novartis, Pfizer, UCB, Sanofi, AbbVie, Galapagos/Alfasigma, MSD, Novartis, Pfizer, UCB, Zahi Touma: None declared. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.