1. Patients with an ARIA-based diagnosis of persistent moderate/severe AR (≥ 2 nasal symptoms suggestive of allergic rhinitis and positive skin prick tests to house dust mite (HDM) (HAL Allergy, Leiden, The Netherlands) at screening. Patients with additional seasonal pollen allergies may be included providing that they are included outside their individual pollen season, and with VAS score for total nasal symptoms of more than 5