Methods: PubMed, EMBASE, Ovid, LILACS, and Cochrane Library databases were searched without limits for studies of any design reporting SCIT or SLIT CSI for pollen allergen. Congress abstracts were included.
Results: Nineteen eligible studies were identified; 8 SCIT (n=947 subjects total; n=340 double-blind placebo-controlled [DBPC]) and 11 SLIT (n=2,668 subjects total; n=565 DBPC). Study characteristics and safety reporting were heterogeneous. No epinephrine administrations were reported. Discontinuation frequencies were ≤5.6% and ≤10% with SCIT and SLIT CSI, respectively. In DBPC SCIT studies, systemic allergic reaction frequency was ≤7.1% with CSI and ≤6.9% with placebo; no systemic allergic reactions with CSI were reported in retrospective studies. In SCIT studies, serious treatment-related adverse event (TRAE) frequency with CSI ranged from 0%−2%; besides local reactions no severe AEs were reported. In DBPC SLIT studies, systemic allergic reaction frequency was ≤2% with CSI and ≤0.55% with placebo; no systemic allergic reactions with CSI were reported in a retrospective study. Overall, 2 serious TRAEs with SLIT CSI were reported. Severe AE frequency in SLIT studies was ≤7.7% for CSI and ≤11.9% with placebo or non-CSI.
Conclusions: No increased safety signal was observed with SCIT or SLIT CSI; however, additional data with standardized regimens and doses are needed.