CORRIGENDUMDate: 09 Feb 2024Manuscript number: ALL-2023-01229.R1Title of Article: Response to Correspondence ALL-2023-01107 “Short-course subcutaneous treatment with PQ Grass strongly improves symptom and medication scores in grass allergy”Authors: P.J. de Kam1, S. Zielen2, J.A. Bernstein3, U. Berger4, M. Berger5, M. Cuevas6, D. Cypcar7, A. Fuhr-Horst8, W.A. Greisner9, M. Jandl10, S. Laßmann11, M. Worm12, J. Matz13, E. Sher14, C. Smith15, G.C. Steven16, R. Mösges17,18, M.H. Shamji19,20, L. DuBuske21, F. Borghese1, K. Oluwayi1, T. Zwingers1, M. Seybold1, O. Armfield1, M.D. Heath1, S.J. Hewings1, M.F. Kramer1, M.A. Skinner1Allergy Therapeutics plc, Worthing, United KingdomChildren and Adolescents Dept., Allergology, Pulmonology & Cystic fibrosis, Goethe University, Frankfurt, GermanyBernstein Clinical Research Center, LLC, Cincinnati, OH, United States of AmericaUniversity of Innsbruck, Department of Botany, Innsbruck, AustriaWiener Gesundheitsverbund, Hospital Hietzing, Department of Otorhinolaryngology, Vienna, AustriaClinic and Polyclinic of Otorhinolaryngology, University Clinic Carl Gustav Carus, TU Dresden, GermanyAllergy Partners of Western North Carolina, Asheville, NC, United States of AmericaENT Research- Institut für klinische Studien, Essen, GermanyBluegrass Allergy Research, Lexington, KY, United States of AmericaHamburger Institut für Therapieforschung GmbH, Hamburg, GermanyStudienzentrum Dr. Sabine Laßmann, Saalfeld, GermanyUniversitätsmedizin Berlin, Department of Dermatology and Allergy - Charite Campus Mitte, Berlin, GermanyChesapeake Clinical Research, Inc. White Marsh, MD, United States of AmericaAllergy Partners of New Jersey, Ocean, NJ, United States of AmericaCertified Research Associates, Cortland, NY, United States of AmericaAllergy Asthma & Sinus Center, S.C., Greenfield, WI, United States of AmericaIMSB (Institute of Computational Biology and Medical Statistics), University at Cologne, Cologne, GermanyClinCompetence, Cologne, GermanyImmunomodulation and Tolerance Group, Allergy and Clinical Immunology, Department of National Heart and Lung Institute, Imperial College London, London, United KingdomAsthma UK Centre in Allergic Mechanisms of Asthma, Imperial College London, London, United KingdomDivision of Allergy and Immunology, Department of Internal Medicine, George Washington University Hospital, Washington, DC, United States of AmericaName of the Corresponding Author: Pieter-Jan De Kam

Response to Correspondence ALL-2023-01107 “Short-course subcutaneous treatment with PQ Grass strongly improves symptom and medication scores in grass allergy”P.J. de Kam1, S. Zielen2, J.A. Bernstein3, U. Berger4, M. Berger5, M. Cuevas6, D. Cypcar7, A. Fuhr-Horst8, W.A. Greisner9, M. Jandl10, S. Laßmann11, M. Worm12, J. Matz13, E. Sher14, C. Smith15, G.C. Steven16, R. Mösges17,18, M.H. Shamji19,20, L. DuBuske21, F. Borghese1, K. Oluwayi1, T. Zwingers1, M. Seybold1, O. Armfield1, M.D. Heath1, S.J. Hewings1, M.F. Kramer1, M.A. Skinner1Allergy Therapeutics plc, Worthing, United KingdomChildren and Adolescents Dept., Allergology, Pulmonology & Cystic fibrosis, Goethe University, Frankfurt, GermanyBernstein Clinical Research Center, LLC, Cincinnati, OH, United States of AmericaAerobiology and Pollen Research Unit, Dept. Oto-Rhino-Laryngology, Medical University Vienna, Vienna, Austria.Wiener Gesundheitsverbund, Hospital Hietzing, Department of Otorhinolaryngology, Vienna, AustriaClinic and Polyclinic of Otorhinolaryngology, University Clinic Carl Gustav Carus, TU Dresden, GermanyAllergy Partners of Western North Carolina, Asheville, NC, United States of AmericaENT Research- Institut für klinische Studien, Essen, GermanyBluegrass Allergy Research, Lexington, KY, United States of AmericaHamburger Institut für Therapieforschung GmbH, Hamburg, GermanyStudienzentrum Dr. Sabine Laßmann, Saalfeld, GermanyUniversitätsmedizin Berlin, Department of Dermatology and Allergy - Charite Campus Mitte, Berlin, GermanyChesapeake Clinical Research, Inc. White Marsh, MD, United States of AmericaAllergy Partners of New Jersey, Ocean, NJ, United States of AmericaCertified Research Associates, Cortland, NY, United States of AmericaAllergy Asthma & Sinus Center, S.C., Greenfield, WI, United States of AmericaIMSB (Institute of Computational Biology and Medical Statistics), University at Cologne, Cologne, GermanyClinCompetence, Cologne, GermanyImmunomodulation and Tolerance Group, Allergy and Clinical Immunology, Department of National Heart and Lung Institute, Imperial College London, London, United KingdomAsthma UK Centre in Allergic Mechanisms of Asthma, Imperial College London, London, United KingdomDivision of Allergy and Immunology, Department of Internal Medicine, George Washington University Hospital, Washington, DC, United States of America

Although there is a considerable body of knowledge about allergen immunotherapy (AIT), there is a lack of data on the reliability of real-world evidence (RWE) in AIT and consequently, a lack of information on how AIT effectively works in real life. To address the current unmet need for an appraisal of the quality of RWE in AIT, the European Academy of Allergy and Clinical Immunology Methodology Committee recently initiated a systematic review of observational studies of AIT, which will use the RELEVANT tool and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) to rate the quality of the evidence base as a whole. The next step will be to develop a broadly applicable, pragmatic “real-world” database using systematic data collection. Based on the current RWE base, and perspectives and recommendations of authorities and scientific societies, a hierarchy of RWE in AIT is proposed, which places pragmatic trials and registry data at the positions of highest level of evidence. There is a need to establish more AIT registries that collect data in a cohesive way, using standardised protocols. This will provide an essential source of real-world data that can be easily shared, promoting evidence-based research and quality improvement in study design and clinical decision-making.