Postmarketing study for assessment of tolerability of a grass allergen immunotherapy tablet (GRAZAX) in patients with rhinitis or rhinoconjunctivitis.

BACKGROUND AND OBJECTIVE: Many patients with grass pollen allergy in Spain have concomitant sensitization to other allergens such as profilin. Since this type of sensitization is more common in Mediterranean countries than in countries where most patients were enrolled in clinical trials on GRAZAX (Phleum pratense 75,000 SQ-T/2, 800 BAU, ALK), the aim of this study was to analyze tolerability to GRAZAX under clinical practice conditions in patients with grass pollen allergy. METHODS: A total of 155 patients were enrolled consecutively in a prospective, open-label, observational study. Adverse reactions were recorded during the first month of treatment at 3 different timepoints: after the first dose, when patients were kept under observation for 30 minutes, and on days 15 and 30 after starting treatment RESULTS: With the first dose, 117 adverse reactions were recorded in 63 patients (40.7%). The commonest reactions (>10% patients) were oral pruritus (25.2%) and throat irritation (24.5%). Ear pruritus was recorded in 7.7%. All reactions but 1 occurred within 30 minutes of administration and all were mild-to-moderate. At the end of treatment, the percentage of patients with adverse reactions had decreased significantly (21.3%). Most adverse reactions (95.2%) were mild-to-moderate and only 3 (1.4%) were severe. No serious adverse reactions were recorded. CONCLUSION: GRAZAX seems to be well tolerated, and most reactions were mild-to-moderate. Many of these reactions occur with the first dose. Therefore, according to the Summary of Product Characteristics, the first dose has to be administered under medical supervision.