 - Exhibit a moderate response to 1500 grass pollen grains per cubic metre after 2 hours in the Vienna Challenge Chamber at screening or within 12 months preceding the screening visit. A moderate response is defined as a total nasal symptom score of at least 6. Total nasal symptom score is the sum of obstruction, rhinorrhoea, itch and sneeze, each of which has been scored on a scale from 0 to 3. 