Validation and Verification of Grass Allergen Challenge in the Allergen Biocube (ABC)

Rationale: Grass allergy can be difficult to study in field trial due to unreliable exposure patterns and poor correlations between skin test response and severity of nasal symptoms. To overcome these challenges, the Allergen BioCube (ABC) was validated for the delivery of Timothy Grass allergen in a uniform manner to a capacity of 25 subjects inducing a clinically meaningful rhinitis response. 

Methods: Twenty five subjects were screened and 14 were enrolled with SPT wheel > 5mm, and no symptoms at the screening Visit 1.  Visits 2, 3, 4 and 5 consisted of 3 hour exposures to 4000+/- 450 grains per cubic meter of timothy pollen in consecutive days.  PNIF, PEFR, serum specific IGE and clinician graded Nasal Inflammation Score (NIS) were captured. The study was conducted out of season.

Results: The average baseline Total Nasal Symptom Score (TNSS) of 0.36 increased to 6.7 ±2.7 after three hours at Visit 2.  This response persisted at Visit 3,4, and 5 with averages of 6.2 ±3.4, 5.5 ±3.5, and 5.5 ±3.5, respectively. From this population 50% of subjects reached a TNSS > 6 by Visit 5.  Similarly the NIS increased to a grade of 3.7 ±1.6 by Visit 5.

Conclusions: The Allergen BioCube creates a clinically meaningful level of rhinitis in a controlled environment which can be used to evaluate the efficacy of therapies without the concern of a poor natural season and within shorter timelines.