Box 1 Short summary of outcomes from the first Workshop on AIT for Children, held at EMA, 26th June 2018 in London, UK

General agreement among experts

 There is a relative need for more clinical studies to confirm sustained and long-term efficacy in children

 At least 3 year treatment duration is required to elicit long-term effect (expert opinion based on clinical observation)

 Three year placebo-controlled trials considered feasible, possible and acceptable (at least from investigator’s point of view—need to get parent’s view) for SLIT products; however considered unfeasible and unacceptable for SCIT products

 Need to have same scoring systems in adults and in children among different manufacturers to allow future comparison of results not only between manufacturers but also between adults and children as basis for extrapolation—(agreed PIPs require the use of the combined score proposed by the EAACI Taskforce Group [6]) at least as secondary endpoint)

 At present there is a lack of validated outcome measures for both adults and children. However, the combined symptom medication score (proposed by EAACI) has been used in well-powered studies in adults and children; this could be accepted as “validation” of this outcome

 At present, there is no agreement on the most appropriate or optimal primary outcome measure to assess long-term efficacy of AIT for allergic rhinitis (AR) and allergic asthma (AA)

 There is an urgent need to move to evidence generation and development of outcome measures which are not dependent on varying pollen exposure which is different from one season to the other

 Manufacturers have been encouraged to explore the use of exposure chambers and compare results to field results, at least in adults—but not many manufacturers so far have followed this recommendation; consequently this comparison between field-exposure and exposure chambers is lacking at present

Proposal to increase likelihood and feasibility of long-term studies in children

 For the PIP, it is recommended to separate SCIT and SLIT protocols

 Proposal: First year double blind evaluation in field and in chamber, then open study and continue with chamber if results were comparable with those in double-blind period—possible to split comparison into 2 studies obviating need to do it in same study/same season?

 Need to ask parents/patients about their expectations—what is important to achieve in term of resolution of symptoms, QoL, no need for medications (in order to improve adherence/compliance during the CTs)

 A follow-up meeting with manufacturers, academia, EUnetHTA, regulators and parent/patient representatives should be considered to find solutions to the discussed proposals