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.