Pre-Coseasonal vs Perennial Sublingual Immunotherapy for Seasonal Allergens Dosing Regimen: Long-Term Benefits, Adherence, and Cost-Effectiveness—Is There a Difference?

Allergen immunotherapy (AIT) is to date the only disease-modifying and etiological treatment for IgE-mediated respiratory allergies. In France and Italy, the main route of administration of AIT for respiratory allergies is currently constituted by sublingual allergen immunotherapy (SLIT). In other European countries, the marketing is growing. In the USA, SLIT is increasingly taking hold, too. Various SLIT regimens have been employed to date for respiratory allergies induced by pollen, which constitutes a major atopic sensitizer in Europe and North America: continuous (all year-round), pre-seasonal only, co-seasonal only, and pre-coseasonal. The best maintenance SLIT regimen is a pivotal issue to clinicians. In fact, a continuous regimen may pose problems of adherence, and patients could be reluctant to take a treatment when they are symptom-free, out of the pollen season. In addition, a continuous treatment carries on a relevant economic cost. Obviously, the economic aspect may not be primary on safety and efficacy. Data provided evidence of short-term, sustained, and post-treatment efficacy of pre-coseasonal regimen. However, further head-to-head studies are required to establish whether discontinuous SLIT regimens are associated with better safety and/or major very long-lasting and preventative benefits than perennial SLIT regimens.