title: Design and recruitment for the GAP trial, investigating the preventive effect on asthma development of an SQ-standardized grass allergy immunotherapy tablet in children with grass pollen-induced allergic rhinoconjunctivitis.
abstract: BACKGROUND
  Allergic rhinoconjunctivitis is a risk factor for asthma development. Treating the underlying allergy may represent an attractive method of asthma prevention. No regulatory guidance exists in this area, and, to our knowledge, no clinical investigations meeting modern regulatory standards have been published.
  
  
  OBJECTIVE
  The objective of this publication is to describe the rationale behind the design of and report on the recruitment for the ongoing pediatric Grazax Asthma Prevention (GAP) trial.
  
  
  METHODS
  The trial was designed for assessment of the preventive effect of an SQ-standardized grass allergy immunotherapy tablet (AIT) on asthma development, both during treatment and after the end of treatment. (The standardized quality [SQ] procedure is a standardization procedure comprising 3 components: total potency, major allergen content, and assessment of extract complexity.) The trial design was discussed with several European Competent Authorities.
  
  
  RESULTS
  The GAP trial is a multinational, parallel-group, double-blind, placebo-controlled randomized trial. Main eligibility criteria were age of 5 to 12 years, grass pollen-induced allergic rhinoconjunctivitis, no asthma, and no overlapping symptomatic allergies. The children have been randomized 1:1 to receive the grass AIT or placebo once daily for 3 years, followed by a blinded observational period of 2 years. Asthma is assessed by the investigators according to specific diagnostic criteria, used at screening visits before randomization to exclude children with existing asthma, and evaluated at least half-yearly during the trial. Seven months of screening resulted in 812 randomized children at 101 centers in 11 countries.
  
  
  CONCLUSIONS
  To our knowledge, the GAP trial represents the first double-blind, placebo-controlled randomized trial to assess the preventive effect of allergen-specific immunotherapy on asthma development. A total of 812 children were successfully recruited into the trial. EudraCT number: 2009-011235-12.
authors: Suomen Terveystalo Allergy Clinic, Turku, Finland. Erkka.Valovirta@terveystalo.com
authors: Erkka
authors: E
authors: Valovirta
authors: Aud Katrine Herland
authors: AK
authors: Berstad
authors: Jacques
authors: J
authors: de Blic
authors: Albrecht
authors: A
authors: Bufe
authors: Peter
authors: P
authors: Eng
authors: Susanne
authors: S
authors: Halken
authors: Pedro
authors: P
authors: Ojeda
authors: Graham
authors: G
authors: Roberts
authors: Lene
authors: L
authors: Tommerup
authors: Eva-Maria
authors: EM
authors: Varga
authors: Inger
authors: I
authors: Winnergard
mesh_terms: D001249:Asthma / Q000209:etiology / Q000276:immunology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D003233:Conjunctivitis, Allergic / Q000150:complications / Q000276:immunology / Q000628:therapy*; D003888:Desensitization, Immunologic / Q000379:methods*; D004311:Double-Blind Method; D023381:Endpoint Determination; D006801:Humans; D006109:Poaceae / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000276:immunology / Q000628:therapy*; D013607:Tablets
chemical_list: D013607:Tablets