Although biologics have demonstrated to be effective in T2-high asthma patients, there is little experience with these drugs in asthma-COPD overlap (ACO). The aim of this study was to compare the effectiveness of biologics in these two conditions. We included 318 patients (24 ACO and 297 asthma) treated with monoclonal antibodies and followed for at least 12 months. Omalizumab was the most frequently employed biologic agent both in patients with ACO and asthma. Asthma control test (ACT) scores after at least 12 months of biologic therapy were not significantly different between groups. The percentage of patients with ≥1 exacerbation and ≥1 corticosteroid burst was significantly higher in ACO patients (70.8 vs 27.3 and 83.3% vs 37.5%, respectively), whereas the percentage of "controlled" patients (with no exacerbations, no need for corticosteroids and ACT ≥ 20) was significantly lower (16.7% vs 39.7%). In conclusion, this report suggests that patients with ACO treated with biologics reach worse outcomes than asthma patients., Competing Interests: Dr. Pérez de Llano reports grants, personal fees and non-financial support from AstraZeneca, personal fees and non-financial support from GSK, grants and personal fees from TEVA, personal fees and non-financial support from Novartis, personal fees and non-financial support from Chiesi, personal fees from Sanofi, personal fees from Menarini, personal fees from Leo-Pharma, personal fees from GEBRO, personal fees from GILEAD, grants and personal fees from Esteve, personal fees from ROVI, personal fees from MSD, personal fees from TECHDOW PHARMA, non-financial support from FAES, outside the submitted work. Dr. Dacal Rivas reports personal fees and non-financial support from Esteve, personal fees and non-financial support from Boehringer-Ingelheim, non-financial support from GSK, non-financial support from Novartis, non-financial support from TEVA, non-financial support from Chiesi, non-financial support from Ferrer, outside the submitted work. Dr. Marina Malanda reports payment for lectures including Service on speakers bureaus, payment for development of educational presentations and travel/accommodations/meeting expenses, outside the submitted work. Dr. Plaza Moral reports grants and personal fees from AstraZeneca, personal fees from Boehringer-Ingelheim, personal fees from GSK, personal fees from Merck, grants and personal fees from Chiesi, personal fees from Novartis, grants from Menarini, personal fees from Sanofi, outside the submitted work. Dr. Gullón has nothing to disclose. Dr. Muñoz Esquerre reports grants, personal fees and non-financial support from AstraZeneca, grants, personal fees and non-financial support from GSK, personal fees and non-financial support from TEVA, personal fees and non-financial support from Novartis, personal fees and non-financial support from Chiesi, personal fees and non-financial support from Sanofi, personal fees and non-financial support from Menarini, personal fees from Ferrer, personal fees and non-financial support from FAES PHARMA, personal fees and non-financial support from MUNDIPHARMA, personal fees and non-financial support from ORIONPHARMA, personal fees and non-financial support from ALK ABELLÓ, outside the submitted work. Dr. García-Moguel reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from AstraZeneca, Sanofi, GSK, Chiesi, Orionpharma, Leti, Stallergenes, Allergy therapeutics; payment for expert testimony from AstraZeneca, Sanofi and GSK, support for attending meetings and/or travel from Novartis, Allergy therapeutics, Stallergenes Greer and TEVA; participation on a data safety monitoring board or advisory board from GSK, AstraZeneca and Sanofi; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from AstraZeneca; receipt of equipment, materials, drugs, medical writing, gifts or other services from GSK. Dr. Díaz Campos reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from GSK, Pfizer and Novartis; payment for expert testimony from GSK, AstraZeneca; support for attending meetings and/or travel from Chiesi, Menarini; Participation on a Data Safety Monitoring Board or Advisory Board from TEVA, GSK. Dr. Martinez-Moragón, declares that in the last three years received honoraria for speaking at sponsored meetings from AstraZeneca, Boehringer-Ingelheim, Chiesi, GlaxoSmithKline, Sanofi, Novartis, TEVA and ALK; and as a consultant for AstraZeneca, Boehringer-Ingelheim and GlaxoSmithKline. Dr. Harbenau Mena reports payment for expert testimony from GSK, AstraZeneca, Sanofi and Novartis. Dr. Cosio reports personal fees from AstraZeneca, grants and personal fees from Boehringer-Ingelheim, grants and personal fees from Novartis, grants and personal fees from Chiesi, personal fees from Sanofi, grants from Menarini, personal fees from Esteve, grants and personal fees from GSK, outside the submitted work. Dr. Padilla-Galo reports grants, personal fees and non-financial support from Astra-Zeneca, personal fees and non-financial support from GSK, TEVA, Chiesi and Novartis, and personal fees from ALK, Sanofi, Mundipharma and Bial, outside the submitted work. Dr. Cisneros reports grants, personal fees and non-financial support from AstraZeneca, personal fees and non-financial support from GSK, grants and personal fees from TEVA, personal fees and non-financial support from Novartis, personal fees and non-financial support from Chiesi, Pfizer, Mundipharma, personal fees from Sanofi, personal fees from Menarini, grants and personal fees from Esteve, personal fees from ROVI, personal fees from MSD, personal fees from TECHDOW PHARMA, non-financial support from FAES, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2022 Pérez de Llano et al.)