Methods: Subjects (study 1: 5-17y; study 2: 18-65y) with grass-pollen–induced AR with or without asthma were randomized 1:1 to once-daily grass AIT (oral lyophilisate, Phleum pratense, 2800 BAU, 75,000 SQ-T) or placebo (PBO), starting approximately 16 weeks before and continuing throughout the grass pollen season. AEs were monitored and assessed for severity.
Results: All randomized subjects but 1 in each study (344/345, study 1; 438/439, study 2) received ≥1 study treatment dose. The most common treatment-emergent (TE) AEs were oral pruritus, throat irritation, and nasopharyngitis (study 1) and oral pruritus, ear pruritus, and upper respiratory tract infection (study 2). TE asthma and urticaria were rare (≤4%). Treatment-related (TR) AEs were reported by 122/175 (70%) of AIT subjects and 43/169 (25%) of PBO subjects in study 1 and 155/213 (73%) of AIT subjects and 62/225 (28%) of PBO subjects in study 2. Most TRAEs were mild or moderate; <2% of subjects had severe TRAEs. Most grass AIT TRAEs were local application-site reactions that began shortly after treatment initiation and resolved within a few days; the rate of new local application-site AEs diminished with treatment over time. Few subjects discontinued because of AEs (study 1: AIT=13/175, PBO=5/169; study 2: AIT=11/213, PBO=8/225). One subject from each study received epinephrine in response to an AIT-related reaction (study 1: moderate [lip angioedema/dysphagia/cough]; study 2: mild [flush/rash/chest discomfort]) at first dose. One subject (study 1) reported a possible AIT-related systemic reaction (dyspnea, chest discomfort, neck pruritus, racing heart, mouth pain). No serious or life-threatening AIT TRAEs or new safety concerns were reported for either study.
Conclusions: Timothy grass AIT was found to be safe and well tolerated in North American adults and children. Incidence and severity of AEs were similar across age groups, supporting the use of the same dose of grass AIT independent of age.