The optimal immunotherapy cluster schedule in clinical practice

The efficacy of injective immunotherapy is no longer a matter of debate, but concerns about its safety and compliance problems (because of the number of visits required for the build-up phase) are limiting factors for wider usage. Different schedules have, therefore, been used in clinical trials with the aim of improving both safety and compliance. We investigated the effects on tolerance of modifications to the starting allergenic dose, of the pharmaceutical presentation of the allergen (aqueous or depot), of the change of the number and volume of the daily administrations through progressive adjustments of the so-called clustered schedule. We took the rate of local and/or systemic side effects as the primary criterion, and were able to gradually reduce the rate of systemic reactions per dose and per patient from 4.1% and 65% to 0.3% and 2.6%, respectively, through four progressive modifications of the starting schedule. According to our data, it is possible to reach the maintenance dose in only four visits with 2 administrations per visit. This was achieved either by switching from aqueous to depot extracts or by using depot extracts from the beginning. These results have been obtained without any kind of premedication and with a wide range of allergens, including mites, epithelia, pollens, and honeybee venom. We have shown that the number of injections administered following the conventional schedule could be reduced by 75%, shortening the build-up phase by 38.5%, without increasing the rate of side effects. We think clustered schedules could lead to a better compliance and to a broader use of injective immunotherapy.