A NEW recombinant birch pollen allergy vaccine has significantly reduced symptoms and medication use during pollen season, according to results from a first-in-human clinical trial.
The findings suggest that a short course of pre-seasonal injections could provide an effective approach to allergen-specific immunotherapy for people with birch pollen allergy.
Birch pollen is a major cause of seasonal allergic rhinitis, with the allergen Bet v 1 responsible for IgE sensitisation in most people with birch pollen allergy.
Researchers investigated GNR-127, a recombinant vaccine designed using peptides derived from Bet v 1 and the related apple allergen Mal d 1. These peptides are fused to a hepatitis B virus-derived PreS surface protein, which acts as an immunological carrier.
The two-stage clinical study first assessed the safety of three GNR-127 doses in 18 patients with birch pollen-induced allergic rhinitis. Participants received five subcutaneous injections at monthly intervals.
Following this Phase I stage, 132 patients entered a single-blind, placebo-controlled Phase II study. Participants were randomised to receive 40 μg GNR-127, 80 μg GNR-127, or placebo, with up to five monthly injections administered before birch pollen season.
During pollen season, researchers measured participants’ combined symptom-medication score (CSMS), which accounts for both allergy symptoms and the medication required to control them.
Compared with placebo, CSMS was reduced by 17.41% among patients receiving 40 μg GNR-127 and by 24.13% in those receiving the 80 μg dose. The reduction reached statistical significance in the 80 μg group.
The higher dose produced a consistent reduction in CSMS across the birch pollen season, suggesting that vaccination before pollen exposure translated into meaningful clinical benefit.
Researchers also observed a strong dose-dependent immune response. Bet v 1-specific IgG antibodies increased approximately nine-fold with the 40 μg dose and 20-fold with the 80 μg dose.
Treatment additionally blunted the seasonal increase in allergen-specific IgE and reduced basophil sensitivity, providing further evidence that the vaccine altered patients’ immune response to birch pollen.
GNR-127 demonstrated an acceptable safety profile at the doses investigated, although some immediate systemic reactions occurred. The researchers stressed that administration should therefore be performed by experienced clinicians.
Importantly, this was an early-phase study involving a relatively small number of patients. Whether the treatment provides sustained protection across multiple pollen seasons remains unknown.
The researchers concluded that a single pre-seasonal course of 80 μg GNR-127 improved birch pollen allergy during the subsequent pollen season while inducing a robust allergen-specific IgG response.
The findings now support further investigation of the vaccine in larger Phase III efficacy studies.
Reference
Khaitov M R et al. Pre-Seasonal Treatment With Recombinant Carrier-Based Birch Vaccine Improves Birch Pollen Allergy. Allergy. 2026.
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