The purpose of this study is to determine whether it is safe to administer Ragweed-SPIRE to subjects suffering from both ragweed allergy and asthma.

Inclusion Criteria:

• Male or female, aged 18-65 years.
• Asthma treated by inhaled SABA or inhaled SABA plus low-medium dose ICS in 6 weeks prior to randomisation.
• A reliable history consistent with moderate to severe rhinoconjunctivitis on exposure to ragweed for at least the previous two ragweed seasons.
• Positive skin prick test to ragweed
• Ragweed-specific Immunoglobulin E (IgE) ≥ 0.35 kU/L.

Exclusion Criteria:

• History of life-threatening asthma.
• Uncontrolled asthma according to GINA
• FEV1 of < 70 % of predicted, regardless of the cause.
• Administration of adrenaline (epinephrine) is contraindicated (e.g. subjects with acute or chronic symptomatic coronary heart disease or severe hypertension).
• History of severe drug allergy or anaphylactic reaction to food.
• A history of any significant disease or disorder (e.g. immune system, pulmonary, cardiovascular, gastrointestinal, liver, renal, neurological, musculoskeletal, endocrine, metabolic, malignant, psychiatric, major physical impairment, history of alcohol or drug abuse)