Efficacy, Safety, and Tolerability Study of ACT-129968 in Patients With Seasonal Allergic Rhinitis

Inclusion Criteria

- Males and females aged 12-76 years with documented clinical history of symptomatic
seasonal allergic rhinitis associated with mountain cedar pollen for the last 2 years.

- Evening reflective Total Nasal Symptom Score (p.m.rTNSS) at least 42 out of a maximum
potential score of 84 over the 7-day run-in period, or > or = 6 out of a maximum score
of 12 on each of the last 4 consecutive days during the run-in period.

Exclusion Criteria

- Non-allergic rhinitis.

- Severe physical nasal obstruction.

- Acute or significant chronic sinusitis.

- Bacterial or viral infection of the upper or lower respiratory tract, nasal sinuses,
or middle ear.

- Ongoing chronic respiratory disorders.

- Asthma requiring use of short-acting beta2-agonists > 2 times a week or any asthma
treatment other than inhaled short-acting beta2-agonists.

- Diagnosis of aspirin or non-steroidal anti-inflammatory drug (NSAID)-induced asthma.

- Nasal biopsy or surgery, sinus surgery, or perforation within the 8 weeks prior to the
Screening Visit.

- Ocular surgery within the 8 weeks prior to the Screening Visit.

- Ocular infections (bacterial or viral) within the 4 weeks before screening.

- Use of forbidden medications (prescribed or over-the-counter [OTC])

- Congenital or acquired severe immunodeficiency or known Human immunodeficiency virus
(HIV)infection.