Author declaration of conflicts of interest:

SC: has received a non-restricted research grant from Sanofi Genzyme for investigator-initiated type 2 innovation research; speaker honoraria from Sanofi Regeneron, AstraZeneca and GlaxoSmithKline (GSK), outside the submitted work. DJ has received advisory board and speaker’s fees from AstraZeneca, Boehringer Ingelheim, Novartis, Teva, and GSK, Sanofi/Regeneron and Chiesi, outside of the submitted work. MEW reports grants and personal fees from Novartis, Sanofi, GSK, and Cohero Health, personal fees from Regeneron, ] Genentech, Sentien, Restorbio, Equillium, Genzyme, grants, personal fees and non-financial support from Teva, personal fees and non-financial support from Boehringer Ingelheim, grants, personal fees and non-financial support from AstraZeneca. IDP: In the last 5 years, IDP has received speaker’s honoraria for speaking at sponsored meetings from AstraZeneca, Boehringer Ingelheim, Aerocrine AB, Almirall, Novartis, Teva, Chiesi, Sanofi/Regeneron, Menarini, and GSK, and payments for organising educational events from AstraZeneca, GSK, Sanofi/Regeneron, and Teva. He has received honoraria for attending advisory panels with Genentech, Sanofi/Regeneron, AstraZeneca, Boehringer Ingelheim, GSK, Novartis, Teva, Merck, Circassia, Chiesi, and Knopp, and payments to support FDA approval meetings from GSK. He has received sponsorship to attend international scientific meetings from Boehringer Ingelheim, GSK, AstraZeneca, Teva, and Chiesi. He has received a grant from Chiesi to support a phase 2 clinical trial in Oxford. He is co-patent holder of the rights to the Leicester Cough Questionnaire and has received payments for its use in clinical trials from Merck, Bayer, and Insmed. In 2014-2015 he was an expert witness for a patent dispute involving AstraZeneca and Teva.

Funding information: There was no funding for this review.