Tolerability of an Immunologically Enhanced Subcutaneous Immunotherapy Preparation in Patients Treated with Concomitant Allergy Immunotherapy: A Non-Interventional Observational Study

Background For causal treatment by allergy immunotherapy (AIT) a single or few allergen products for the clinically most relevant allergens are applied to treat multiple allergies, but few data on the tolerability of multiple AIT applications are available. Objective The aim of our study was to investigate safety and tolerability in patients treated by subcutaneous immunotherapy (SCIT) and concomitant SCIT or sublingual immunotherapy (SLIT) products. Methods In a non-interventional, observational study in Germany treatment of patients with a primary SCIT and concomitant AIT (SCIT or SLIT) was documented during the first 4 months of treatment. Adverse events (AEs) were recorded by the physicians and by patients in diaries, and coded using the Medical Dictionary for Regulatory Activities (MedDRA). Results Three hundred and seven patients were treated with the primary SCIT by 79 allergists, and 271 received a concomitant AIT. AEs were reported in 92 (33.9%) patients and adverse drug reactions (ADRs) in 63 (23.2%) patients related to the primary SCIT and in 69 (25.5%) to the concomitant AIT; six (2.2%) patients discontinued due to ADRs. ADRs were mild or moderate in 40 (14.8%) patients, severe in 23 (8.5%), and serious in one patient. The most frequent reactions were local swelling and pruritus. Overall tolerability was assessed as ‘good’ or ‘very good’ by 95.6% of patients and 96.7% of physicians. Conclusions Compared with data from a large previous study no increase in the frequency of ADRs in real life or change in the tolerability profile was observed for SCIT with concomitant SCIT or SLIT.