Positive results of study recombinant Bet v 1

Successful proof of concept study of recombinant Bet v 1 efficacy in desensitization against birch pollen allergy

Objective:

Birch pollen is one of the most frequent cause of Respiratory Allergy in Central Europe, Northern Europe and Northern America.

Aim of the DV08.01 study was to demonstrate:

1. desensitization based on major allergen (Bet v 1) is as effective and safe as current marketed total extract;
2. recombinant Bet v 1 is as effective and safe as purified natural Bet v 1

Study Plan

Subcutaneous administration was used. DV08.01 study was a randomized, double blinded, comparative study versus placebo conducted in 5 European countries (150 randomized patients). Length of study was 3 years (2003: baseline – 2004 and 2005: treatment).
Patients were randomized in 4 groups: commercial extract, recombinant Bet v 1 and purified natural Bet v 1 (active groups) and placebo.

Results

The 3 active groups showed very significant improvement of rhino conjunctivitis symptoms versus placebo after year 1 of desensitization as well as after year 2 (>50%; p<0.001).
In these 3 active groups, very significant reduction of rescue medication usage was demonstrated versus placebo after year 1 and after year 2 (>60%; p < 0.004). No significant difference was demonstrated between the 3 active groups.

Safety was also very satisfying in all groups. Only one anaphylactic reaction occurred in the group treated with natural Bet v 1.

Conclusions and next steps

• Bet v 1, as a major allergen, is as effective as the total birch pollen extract to desensitize.
• Recombinant Bet v 1 is as effective as purified natural Bet v 1 or birch pollen extract to desensitize.

“We are of course very satisfied to be the first allergen company to demonstrate the therapeutic effect of a recombinant major wild type allergen. On the basis of this study, we are undertaking a development program for a new tablet for sublingual desensitization :

ORALAIR® Birch based on recombinant Bet V1 produced under the license agreement signed 3 years ago with BIOMAY, Vienna, Austria.” says Albert Saporta, Chairman & CEO of Stallergenes.