Safety of sublingual immunotherapy with monomeric allergoid in adults: multicenter post-marketing surveillance study

Sublingual immunotherapy (SLIT) appears to be acceptably safe in clinical trials, but post-marketing data are needed to provide essential information. This study specifically evaluated the safety of commercial SLIT in adult patients in a post-marketing phase. A total of 198 patients (83 male, 115 female, mean age 24.4 years) receiving SLIT for respiratory allergy were followed up for 3 years by a specific questionnaire for side-effects. SLIT (LAIS, Lofarma SpA, Milan, Italy), a monomeric allergoid in tablets, was administered, in association with drug therapy, pre- or pre-coseasonally for pollen and continuously for mites. The average duration was 12-36 months, and the total of doses was about 32 800. Side-effects were grouped as ocular, gastrointestinal, rhinitis, asthma, urticaria, edema of tongue/lips, and anaphylaxis. The severity was graded as low (no need for treatment or dose adjusting, no interference with activities), moderate (interference with activities/need for drugs/SLIT discontinuation), and severe (life-threatening/hospitalization/emergency care). Seventeen events corresponding to 7.5% of patients and 0.52 per 1000 doses were reported. Seven episodes of rhinitis (two in two patients), three of oral itching, and one of abdominal pain were self-limiting. Two cases of urticaria and two of abdominal pain/nausea were controlled by a temporary dose-adjustment, and one case of urticaria and conjunctivitis required oral antihistamines. Medical intervention was needed in six patients only during a 3-year period. The results of this study, performed in a real situation of clinical practice, confirm the satisfactory safety profile of SLIT.