Wenjia Chen,1 Mohsen Sadatsafavi,2 Trung N Tran,3 Ruth B Murray,4 Chong Boon Nigel Wong,1 Nasloon Ali,4,5 Cono Ariti,4,5 Esther Garcia Gil,6 Anthony Newell,5,7 Marianna Alacqua,8 Mona Al-Ahmad,9 Alan Altraja,10 Riyad Al-Lehebi,11,12 Mohit Bhutani,13 Leif Bjermer,14 Anne Sofie Bjerrum,15 Arnaud Bourdin,16 Lakmini Bulathsinhala,4,5 Anna von Bülow,17 John Busby,18 Giorgio Walter Canonica,19,20 Victoria Carter,4,5 George C Christoff,21 Borja G Cosio,22 Richard W Costello,23 J Mark FitzGerald,24 João A Fonseca,25 Kwang Ha Yoo,26 Liam G Heaney,27 Enrico Heffler,19,20 Mark Hew,28,29 Ole Hilberg,30 Flavia Hoyte,31,32 Takashi Iwanaga,33 David J Jackson,34,35 Rupert C Jones,36 Mariko Siyue Koh,37,38 Piotr Kuna,39 Désirée Larenas-Linnemann,40 Sverre Lehmann,41 Lauri A Lehtimäki,42,43 Juntao Lyu,5,7 Bassam Mahboub,44,45 Jorge Maspero,46,47 Andrew N Menzies-Gow,48 Concetta Sirena,49 Nikolaos Papadopoulos,50,51 Andriana I Papaioannou,52 Luis Pérez de Llano,53,54 Diahn-Warng Perng,55,56 Matthew Peters,57 Paul E Pfeffer,58,59 Celeste M Porsbjerg,17 Todor A Popov,60 Chin Kook Rhee,61 Sundeep Salvi,62 Camille Taillé,63 Christian Taube,64 Carlos A Torres-Duque,65 Charlotte S Ulrik,66 Seung Won Ra,67 Eileen Wang,31,32 Michael E Wechsler,68 David B Price4,5,69 1Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore; 2Respiratory Evaluation Sciences Program, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada; 3AstraZeneca, Gaithersburg, MD, USA; 4Optimum Patient Care, Cambridge, UK; 5Observational and Pragmatic Research Institute, Singapore, Singapore; 6AstraZeneca, Barcelona, Spain; 7Optimum Patient Care, Queensland, VIC, Australia; 8AstraZeneca, Cambridge, UK; 9Microbiology Department, Faculty of Medicine, Kuwait University, Al-Rashed Allergy Center, Ministry of Health, Kuwait City, Kuwait; 10Department of Pulmonology, University of Tartu and Lung Clinic, Tartu University Hospital, Tartu, Estonia; 11Department of Pulmonology, King Fahad Medical City, Riyadh, Saudi Arabia; 12College of Medicine, Alfaisal University, Riyadh, Saudi Arabia; 13Department of Medicine, Division of Pulmonary Medicine, University of Alberta, Western Canada, AB, Canada; 14Department of Clinical Sciences, Respiratory Medicine and Allergology, Skåne University Hospital, Lund University, Lund, Sweden; 15Department of Respiratory Medicine and Allergy, Aarhus University Hospital, Jutland, Aarhus, Denmark; 16PhyMedExp, Univ Montpellier, CNRS, INSERM, CHU Montpellier, Montpellier, France; 17Respiratory Research Unit, Bispebjerg University Hospital, Copenhagen, Denmark; 18Centre for Public Health, Queen’s University Belfast, Belfast, Northern Ireland; 19Personalized Medicine, Asthma and Allergy, Humanitas Clinical and Research Center IRCCS, Milan, Italy; 20Department of Biomedical Sciences, Humanitas University, Milan, Italy; 21Medical University-Sofia, Faculty of Public Health, Sofia, Bulgaria; 22Son Espases University Hospital-IdISBa-Ciberes, Mallorca, Spain; 23Department of Respiratory Medicine, Clinical Research Centre, Smurfit Building Beaumont Hospital, RCSI, Dublin, Ireland; 24Department of Medicine, the University of British Columbia, Vancouver, BC, Canada; 25Comunity Health, Information and Decision Sciences Department (MEDCIDS) & Center for Health Technology and Services Research (CINTESIS), Faculty of Medicine of University of Porto, Porto, Portugal; 26KonKuk University School of Medicine in Seoul, Seoul, Korea; 27Wellcome-Wolfson Centre for Experimental Medicine, Queen’s University Belfast, Belfast, Northern Ireland; 28Allergy, Asthma & Clinical Immunology Service, Alfred Health, Melbourne, VIC, Australia; 29Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia; 30Medical Department, Vejle University Hospital, Jutland, Vejle, Denmark; 31Department of Medicine, Division of Allergy and Clinical Immunology, National Jewish Health, Denver, CO, USA; 32Department of Internal Medicine, Division of Allergy & Clinical Immunology, University of Colorado School of Medicine, Aurora, CO, USA; 33Center for General Medical Education and Clinical Training, Kindai University Hospital, Osakasayama, Japan; 34UK Severe Asthma Network and National Registry, Guy’s and St Thomas’ NHS Trust, London, UK; 35School of Immunology & Microbial Sciences, King’s College London, London, UK; 36Research and Knowledge Exchange, Plymouth Marjon University, Plymouth, UK; 37Respiratory & Critical Care Medicine, Singapore General Hospital, Singapore, Singapore; 38SingHealth Duke-NUS Lung Centre, Singapore, Singapore; 39Division of Internal Medicine, Asthma and Allergy Medical University of Łódź, Łódź, Poland; 40Directora Centro de Excelencia en Asma y Alergia, Hospital Médica Sur, Ciudad de México, Mexico; 41Section of Thoracic Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway; 42Allergy Centre, Tampere University Hospital, Tampere, Finland; 43Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; 44College of Medicine, University of Sharjah, Sharjah, United Arab Emirates; 45Rashid Hospital, Dubai Health Authority, Dubai, United Arab Emirates; 46Clinical Research for Allergy and Respiratory Medicine, CIDEA Foundation, Buenos Aires, Argentina; 47University Career of Specialists in Allergy and Clinical Immunology at the Buenos Aires University School of Medicine, Buenos Aires, Argentina; 48Royal Brompton & Harefield Hospitals, London, UK; 49Severe Asthma Network in Italy (SANI), Milano, Italy; 50Division of Infection, Immunity & Respiratory Medicine, University of Manchester, Manchester, UK; 51Allergy Department, 2nd Pediatric Clinic, University of Athens, Athens, Greece; 52 2nd Respiratory Medicine Department, National and Kapodistrian University of Athens Medical School, Attikon University Hospital, Athens, Greece; 53Pneumology Service, Lucus Augusti University Hospital, EOXI Lugo, Lugo, Spain; 54Biodiscovery Research Group, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain; 55Division of Clinical Respiratory Physiology Chest Department, Taipei Veterans General Hospital, Taipei, Taiwan; 56COPD Assembly of the Asian Pacific Society of Respirology Hongo, Bunkyo-ku, Tokyo, Japan; 57Department of Thoracic Medicine, Concord Hospital, Sydney, NSW, Australia; 58Department of Respiratory Medicine, Barts Health NHS Trust, London, UK; 59Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK; 60University Hospital ”sv. Ivan Rilski”, Sofia, Bulgaria; 61Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, South Korea; 62Pulmocare Research and Education Foundation, Pune, India; 63Department of Respiratory Diseases, Bichat Hospital, AP-HP Nord-Université de Paris, Paris, France; 64Department of Pulmonary Medicine, University Medical Center Essen-Ruhrlandklinik, Essen, Germany; 65CINEUMO, Respiratory Research Center, Fundación Neumológica Colombiana, Bogotá, Colombia; 66Department of Respiratory Medicine, Copenhagen University Hospital-Hvidovre, Hvidovre, Denmark; 67Department of Internal Medicine, Division of Pulmonology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea; 68Department of Medicine, NJH Cohen Family Asthma Institute, National Jewish Health, Denver, CO, USA; 69Centre of Academic Primary Care, Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UKCorrespondence: David B Price, Observational and Pragmatic Research Institute, 22 Sin Ming Lane, #06 Midview City, Singapore, Singapore, 573969, Tel +65 3105 1489, Email dprice@opri.sgBackground: Many severe asthma patients with high oral corticosteroid exposure (HOCS) often do not initiate biologics despite being eligible. This study aimed to compare the characteristics of severe asthma patients with HOCS who did and did not initiate biologics.Methods: Baseline characteristics of patients with HOCS (long-term maintenance OCS therapy for at least 1 year, or ≥ 4 courses of steroid bursts in a year) from the International Severe Asthma Registry (ISAR; https://isaregistries.org/), who initiated or did not initiate biologics (anti-lgE, anti-IL5/5R or anti-IL4R), were described at the time of biologic initiation or registry enrolment. Statistical relationships were tested using Pearson’s chi-squared tests for categorical variables, and t-tests for continuous variables, adjusting for potential errors in multiple comparisons.Results: Between January 2015 and February 2021, we identified 1412 adult patients with severe asthma from 19 countries that met our inclusion criteria of HOCS, of whom 996 (70.5%) initiated a biologic and 416 (29.5%) did not. The frequency of biologic initiation varied across geographical regions. Those who initiated a biologic were more likely to have higher blood eosinophil count (483 vs 399 cells/μL, p=0.003), serious infections (49.0% vs 13.3%, p< 0.001), nasal polyps (35.2% vs 23.6%, p< 0.001), airflow limitation (56.8% vs 51.8%, p=0.013), and uncontrolled asthma (80.8% vs 73.2%, p=0.004) despite greater conventional treatment adherence than those who did not start a biologic. Both groups had similar annual asthma exacerbation rates in the previous 12 months (5.7 vs 5.3, p=0.147).Conclusion: Around one third of severe HOCS asthma patients did not receive biologics despite a similar high burden of asthma exacerbations as those who initiated a biologic therapy. Other disease characteristics such as eosinophilic phenotype, serious infectious events, nasal polyps, airflow limitation and lack of asthma control appear to dictate biologic use.Keywords: severe asthma, biologics, real-world, treatment pattern, patient characteristics