Efficacy of a rush immunotherapy with a depigmented polymerized extract of grass pollen using an enviromental challenge chamber (ECC)
RATIONALE: To avoid environmental variations the efficacy of a 5 weeks rush immunotherapy with Depigoid Grass Mix was investigated in patients with allergic rhinitis under standardized ECC conditions. METHODS: Patient selection: 60 male and female patients aged 18 to 54 years with hay fever due to grass pollen sensitization were enrolled based on an at least moderate response upon 4000 Dactylis glomerata pollen grains/m3 within 2 hours in the ECC. Main exclusion criteria: Clinically significant sensitization against tree pollen, weed pollen and perennial allergens, persistent asthma (GINA >= II). Treatment: Immunotherapy was performed using with 1000 DPP/ml depigmented and polymerized allergenic extract of grass pollen. The rush treatment began with 0.2 ml followed by 0.3 ml after 30 min at day 1 and followed by 0.5 ml/week at weeks 1-5. Placebo treatment was performed identically using Depigoid vehicle. Primary outcome was the change from baseline in the mean "Total Nasal Symptom Score" (TNSS) during the allergen challenge for the symptoms rhinorrhea, nasal congestion, sneezing and nasal itching on a scale from 0-3 (none -severe) for each symptom. RESULTS: Analysis was based on the ITT set (N 5 60) using an ANCOVA model. In patients with a baseline severity of TNSS >= 6 the prepost difference of the mean TNSS was -2.57 in the Depigoid Grass Mix and -1.38 in the placebo group. The overall difference between both treatments was statistically significant (p 5 0.03). CONCLUSIONS: Short-term rush immunotherapy with Depigoid Grass Mix was effective and safe.