Conditions: Allergy
Keywords: House dust mites Sublingual immunotherapy Allergy Allergic asthma
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 124
Healthy volunteers: no

Brief summary:
This trial has been designed to evaluate the efficacy of specific immunotherapy with SLITone Dermatophagoides mix compared with placebo in subjects with house dust mite allergic asthma, based on asthma medication use during a period of 2 months with a high environmental exposure to mites (autumn 2008).

Detailed description:
This trial was conducted as a multi-centre, randomised, double-blind, parallel-group, placebo-controlled phase III trial, assessing the efficacy of SLITone Dermatophagoides mix in adults (18-65 years). 5 centres in Spain participated.

Subjects with house dust mite allergic asthma were randomised to receive either SLITone Dermatophagoides mix (active) or placebo treatment (1:1) for approximately 1 year. The trial duration was extended to 2 years. Administration was done sublingually (under the tongue) once daily preferably in the morning. A monodose container comprised the daily dose of 200 STU.

Subjects were kept in asthma control during the entire trial (2 years). Except for during 2 evaluation periods of 2 months in autumn 2007 and autumn 2008, subjects used the medications prescribed by their physician. During the 2 evaluation periods of 2 months in autumn 2007 and autumn 2008, subjects used provided and standardised rhinoconjunctivitis and asthma medications. The asthma medication use was to reflect the subject's asthma status. This was done by treatment with a low maintenance dose of control medication supplemented with rescue medication as needed.

Rhinoconjunctivitis medication during the 2 evaluation periods in autumn 2007 and autumn 2008; to standardise the medication used to relieve rhinoconjunctivitis symptoms, subjects were provided with the following free medications as needed:

* Desloratadine tablet (5 mg per tablet; anti-histamine; Aerus®)
* Budesonide nasal spray (64 µg per puff; inhaled corticosteroid)
* Prednisone tablet (5 mg per tablet; oral corticosteroid)

Subjects were instructed to use this medication instead of their usual medication during the 2 evaluation periods in autumn 2007 and autumn 2008, and to record the used medication and symptoms in the daily diary.

Asthma medication during the evaluation period in autumn 2007; prior to the 2 months evaluation period in autumn 2007, the asthma control medication use was interrupted to obtain a medication-free period. Subjects were provided with the following free medications to standardise the treatment used to relieve asthma symptoms:

* Salbutamol inhaler (200 µg per puff; a short acting β2-agonist; Ventilastin®).
* Budesonide/formoterol inhaler (80/4.5 µg per inhalation; a combination of inhaled corticosteroids and long acting β2-agonist; Symbicort®).
* Prednisone tablet (5 mg per tablet; oral corticosteroid).

Subjects were instructed to use this medication instead of their usual medication during the evaluation period in autumn 2007 as follows:

They were to use salbutamol inhaler as asthma rescue medication until they either:

* needed more than 4 inhalations of salbutamol per day for 2 consecutive days
* suffered from nocturnal asthma forcing them to wake up
* suffered from exercise-induced dyspnoea doing ordinary tasks In these cases, subjects were to contact the investigator to determine the amount of budesonide/formoterol to use as daily asthma control medication. The budesonide/formoterol inhaler was thereafter to be used as rescue medication as needed instead of salbutamol. Prednisone could be used as a last option.

Asthma medication during the evaluation period in autumn 2008: At the 2 months evaluation period in autumn 2008, subjects were maintained at a low dose of budesonide/formoterol (daily asthma control medication) and they used the budesonide/formoterol inhaler as rescue medication as needed. Prednisone could be used as a last option.

Asthma medication used during the evaluation periods in autumn 2007 and autumn 2008 were recorded in a daily diary.

One primary efficacy endpoint and 16 secondary efficacy endpoints were assessed; the result of the primary efficacy endpoint, 3 secondary endpoints and adverse event reportings are posted here. None of the other secondary endpoints demonstrated a difference between treatment groups.

Arms:
arm 1: SLITone Dermatophagoides Mix arm 2: SLITone Placebo

Interventions: intervention 1: SLITone(TM) Dermatophagoides mix intervention 2: Placebo intervention 3: Salbutamol inhaler intervention 4: Budesonide/formoterol inhaler intervention 5: Prednisone tablet intervention 6: Desloratadine tablet intervention 7: Budesonide nasal spray
Intervention descriptions: intervention 1: Sublingual immunotherapy with SLITone Dermatophagoides mix (200 STU) once daily for 2 years intervention 2: Sublingual immunotherapy once daily for 2 years intervention 3: 200 µg per puff; a short acting beta2-agonist (please refer to the 'detailed description' for details on the use) intervention 4: 80/4.5 µg per inhalation; a combination of inhaled corticosteroids and long acting beta2-agonist (please refer to the 'detailed description' for details on the use) intervention 5: 5 mg per tablet; oral corticosteroids (please refer to the 'detailed description' for details on the use) intervention 6: 5 mg per tablet: anti-histamine (please refer to the 'detailed description' for details on the use) intervention 7: 64 µg per puff; inhaled corticosteroid (please refer to the 'detailed description' for details on the use)

Protocol document: