A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Efficacy and safety of birch pollen allergoid subcutaneous immunotherapy: a 2-year double-blind, placebo-controlled, randomized trial plus 1-year open-label extension
Tekijät: Worm Margitta, Rak Sabina, Samoliński Boleslaw, Antila Jukka, Höiby Ann-Sofi, Kruse Brigitte, Lipiec Agnieszka, Rudert Michael, Valovirta Erkka
Kustantaja: Blackwell Scientific
Julkaisuvuosi: 2019
Journal: Clinical and Experimental Allergy
Tietokannassa oleva lehden nimi: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology
Lehden akronyymi: Clin Exp Allergy
Vuosikerta: 49
Numero: 4
Aloitussivu: 516
Lopetussivu: 525
Sivujen määrä: 10
ISSN: 0954-7894
eISSN: 1365-2222
DOI: https://doi.org/10.1111/cea.13331
Background: Previous clinical trials with birch pollen subcutaneous immunotherapy have been conducted over a 1-2 year treatment period and involved mostly a single geographic location.
Objective: This study (EudraCT-Number: 2005-000025-35) intended to evaluate the effect of subcutaneous immunotherapy with high-dose hypoallergenic birch pollen allergoid in patients with confirmed moderate to severe seasonal allergic rhinitis/rhinoconjunctivitis over a 3-year course in 19 European centers.\nAdults with confirmed birch pollen allergy (n=253) were randomized to preseasonal placebo (n=129) or active treatment (n=124). Primary endpoint was change in Symptom Medication Score after 2 years treatment (2007).
Methods: The change in Symptom Medication Score of active- versus placebo-treated patients for the Full Analysis Set (n=227, 15.2% reduction, p=0.0710) and Per-Protocol Set (n=216, 16.7% reduction, p=0.0523) showed a positive trend, although significance was not achieved. The primary endpoint, assessed in 2007, coincided with the lowest pollination during the study period. In a subgroup analysis of patients in the north-eastern region (n=102), where birch is the major tree and consequently patients' exposure is higher, changes in Symptom Medication Score (32.7% reduction, p=0.0034) and median number of well days (p=0.0232) were highly significant in favor of the active group. During the open-label third year of treatment, the mean Symptom Medication Score of active-treated patients was further reduced despite an increased pollen count. Subcutaneous immunotherapy was well tolerated and consistent with the known safety profile.
Results: Although the primary endpoint was not reached for the Full Analysis Set, a significant and clinically relevant effect on Symptom Medication Score was clearly demonstrated for the subgroup of patients in the north-eastern region of Europe, where birch is the predominant tree species. Proving efficacy of birch allergen subcutaneous immunotherapy is challenging due to the numerous factors influencing birch pollen allergen exposure in field studies.
