Safety of Cat-PAD to Treat Cat Allergy in Cat Allergic Subjects With Controlled Asthma

This study is designed as a randomised, double-blind, placebo-controlled, parallel group, multiple dose study to evaluate the safety and tolerability of Cat-PAD in cat allergic subjects with allergic rhinoconjunctivitis and controlled asthma. The efficacy of Cat-PAD will also be explored in these subjects using the EPSR, LPSR, CPT, and levels of cat specific IgE. A single centre will be initiated first, with a second centre included as a backup, if needed, to enable recruitment numbers to be met.

Three cohorts will be studied, depending on the treatment used to control the subject's asthma:Cohort 1 - inhaled salbutamol only, Cohort 2 - inhaled corticosteroid only, Cohort 3 - inhaled corticosteroid plus a LABA

The study will consist of 3 study periods. In Period 1, Screening will be performed up to a maximum of 8 weeks before randomisation and may consist of one or two visits to the clinic, at the investigator's discretion. Baseline Challenge will consist of a single visit 1 to 4 weeks before randomisation.

In Period 2, subjects in each cohort complying with the inclusion/exclusion criteria will be randomised to either 3 nmol Cat-PAD or placebo. Treatments will be administered every 2 weeks (±2 days) for 14 week

In Period 3, Post Treatment Challenge consist of a single visit 24-28 weeks after the first administration in the treatment period and assessments will be performed identical to those at the baseline challenge. Follow-up will be conducted 3-10 days after PTC.