An exploratory, randomised, double blind, placebo controlled, 14 day, two-way crossover, inhaled allergen challenge study to evaluate the effects of SMP-028 in subjects with mild to moderate asthma - SMP-028 Inhaled Allergen Challenge study

Male subjects and females of non-child bearing potential (e.g. post-menopausal (no menstrual bleeding for at least the preceding 12 months) or surgically sterilised), between 18 and 65 years of age inclusive.

Documented history of bronchial asthma, first diagnosed at least 6 months prior to the Screening visit and currently being treated only with intermittent short-acting beta-agonist therapy by inhalation.

Pre-bronchodilator FEV1 >65% of predicted at Screening.

Demonstration of a positive wheal reaction (= 3 mm relative to negative control) to at least one of three allergens (house dust mite, grass pollen, cat hair and dander) on skin prick testing at Screening, or within 12 months of study start.

Screening allergen challenge demonstrating that the subject experiences both an early and late asthmatic response. The early asthmatic response must include a fall in FEV1 of = 20% from the post-saline or diluent value, on at least 1 occasion, between 5 and 30 minutes after the final concentration of allergen. The late asthmatic response must include a fall in FEV1 of = 15% from the post-saline or diluent value, on at least 3 occasions, 2 of which must be consecutive, between 4 and 10 hours after the final concentration of allergen.

Sensitivity to AMP with a provocative concentration of AMP resulting in a 20% fall in FEV1 (PC20 AMP) of < 80mg/mL at Screening.

Are the trial subjects under 18? no

Number of subjects for this age range:

F.1.2 Adults (18-64 years) yes

F.1.2.1 Number of subjects for this age range

F.1.3 Elderly (>=65 years) no

F.1.3.1 Number of subjects for this age range

A subject will not be eligible for inclusion in this study if any of the following criteria apply:

Past or present disease, which as judged by the Investigator, may affect the outcome of this study. These diseases include, but are not limited to, cardiovascular disease, malignancy, hepatic disease, renal disease, haematological disease, neurological disease, endocrine disease or pulmonary disease (including but not confined to chronic bronchitis, emphysema, bronchiectasis or pulmonary fibrosis).

Subject has known history of uncontrolled hypertension or is hypertensive at Screening. Hypertension at Screening is defined as persistent systolic blood pressure (BP) >150mmHg or diastolic BP > 90mmHg. Subjects with well controlled essential hypertension may be enrolled provided that their antihypertensive medication(s) are permitted.

Respiratory tract infection and/or exacerbation of asthma within 4 weeks prior to the first dose of study drug.

Symptomatic allergic rhinitis (those with a history of allergic rhinitis may participate if asymptomatic at Screening and if, in the opinion of the Investigator, it is unlikely that disease exacerbation will occur during the course of the study.

History of life-threatening asthma, defined as an asthma episode that required intubation and/or was associated with hypercapnoea, respiratory arrest and/or hypoxic seizures.

Administration of oral, injectable or dermal steroids within 3 months and/or inhaled steroids within 1 month of the Screening Visit.

Has taken Xanthines (including theophylline, but not including caffeine), anticholinergics, cromoglycates and/or long-acting beta-agonists within 1 week prior to Screening and is unable to abstain from them throughout the study.

History of being unable to tolerate or complete AMP or allergen challenge tests.

If on more than two occasions, after 2 concurrent administrations of saline during the allergen challenge at Screening the subjects still have a fall in FEV1 of greater than 10%.