Safety of two cluster schedules for subcutaneous immunotherapy in allergic rhinitis or asthma patients sensitized to inhalant allergens.

BACKGROUND

Subcutaneous immunotherapy (SCIT) usually requires a long titration phase, which can be associated with various adverse events (AEs).

OBJECTIVE

It was the aim of this study to determine the safety of 2 cluster regimens for SCIT in patients with allergic rhinitis, with or without mild or moderate allergic asthma, who were sensitized to grass and/or tree pollen, or house dust mites (HDM).

METHODS

Adult patients were included in a European, open-label, prospective trial. Pollen-allergic patients received grass pollen, grass and olive pollen, or hazel, alder and birch pollen according to a 3-week titration cluster. HDM-allergic patients received HDM extract according to a 2-week titration cluster. The safety of the titration phase was assessed in terms of local and systemic AEs.

RESULTS

The safety analysis included 157 patients: 110 received pollen and 47 HDM extract. During the cluster titration, 248 AE episodes were reported in the pollen group and 113 in the HDM group; these were mainly local reactions. Around one third of patients (30.9% pollen and 38.3% HDM) did not experience any AE. In most cases (67.1% of pollen and 71.1% of HDM patients), AEs did not lead to a change in titration schedule. No anaphylactic reaction or other serious life-threatening systemic AEs were reported. Only 2 patients in the HDM group discontinued treatment because of AEs.

CONCLUSIONS

Rapid cluster titration was well tolerated in adults with allergic rhinitis, with or without mild to moderate allergic asthma, due to pollen or HDM. This short-titration, high-dose cluster regime may allow better patient compliance and cost savings.