Allergy immunotherapy with a hypoallergenic recombinant birch pollen allergen rBet v 1-FV in a randomized controlled trial.
BACKGROUND
Pollen extracts and chemically modified allergoids are used successfully in allergen immunotherapy (AIT). Recombinant extracts offer potential advantages with respect to pharmaceutical quality, standardization and dosing. A hypoallergenic recombinant folding variant of the major birch pollen allergen (rBet v 1-FV) was compared with an established native birch preparation. A pre-seasonal, randomized, actively controlled phase II study was performed in birch pollen allergic rhino-conjunctivitis with or without asthma, GINA I/ II. 51 patients (24 rBet v 1-FV, 27 native extract) started therapy with subcutaneous allergen immunotherapy (SCIT). Primary end-point was a combined symptom medication score (SMS), changes in nasal provocation test, visual rating score and specific antibody responses secondary end-points.


RESULTS
After one pre-seasonal treatment course the combined SMS was 5.86 (median; IQR: 14.02) for the rBet v 1-FV group versus 12.40 (median; IQR: 9.32) for the comparator during the three weeks pollen season (p = 0.330). After treatment in the second year, scores were 3.00 (median; IQR: 6.50) and 2.93 (4.86) respectively. Allergen tolerance in a nasal provocation test improved to a comparable extent in both groups. Significant increases in birch pollen-specific IgG1 and IgG4 were observed in both treatment groups following the first treatment phase and remained significantly raised until the end of the study.


CONCLUSIONS
In this first in man, proof of concept phase II trial no statistical difference between rBet v 1-FV and an established natural pollen extract could be observed. rBet v 1-FV could be administered in higher doses than the native protein with no increase in adverse effects.


BACKGROUND
The study was registered in clinicalTrials.gov (NCT00266526).
Center for Rhinology and Allergology, An den Quellen 10, D-65183 Wiesbaden, Germany.
Ludger
L
Klimek
Upper Airway Research Laboratory, University Hospital Ghent, Ghent, Belgium.
Claus
C
Bachert
Institut für Atemwegsforschung (IFA) GmbH, Düsseldorf, Germany.
Karl-Friedrich
KF
Lukat
Center for Rhinology and Allergology, An den Quellen 10, D-65183 Wiesbaden, Germany.
Oliver
O
Pfaar
Medical Department, Allergopharma GmbH & Co. KG, Reinbek, Germany.
Hanns
H
Meyer
Medical Department, Allergopharma GmbH & Co. KG, Reinbek, Germany.
Annemie
A
Narkus
Allergic rhinitis; Allergy immunotherapy; Birch pollen; Folding variant; Hypoallergenic variant; Recombinant Bet v 1; Recombinant allergen; Rhino-conjunctivitis; Subcutaneous immunotherapy