In a placebo- and active-controlled clinical study of patients aged >15 years with seasonal allergic rhinitis⁴

SINGULAIR 10 mg (n=344) vs placebo (n=351):
–0.39 vs –0.26 (P<0.001)^a

Active control (loratadine 10 mg) (n=599) vs placebo
(n=351): –0.46 vs –0.26 (P<0.001)^a

The study was not designed for statistical comparison
between SINGULAIR and the active control.

^a Mean change from baseline. Mean symptom score:
0–3 scale.
^b Versus placebo.

Study Design
Study I: A multicenter, double-blind, randomized, 2-period, placebo- and active-controlled, parallel-group study (N=1,302) conducted under in-house blinding procedures during the spring allergic rhinitis season. Study medication was administered once daily at bedtime.⁴

In a placebo-controlled clinical study of patients aged >15 years with perennial allergic rhinitis^5,6

SINGULAIR 10 mg (n=1,000) vs placebo (n=980):
–0.42 vs –0.35 (P<0.001)^a

^a Mean change from baseline. Mean symptom
score: 0–3 scale.
^b Versus placebo.

Study Designs
Study II (pivotal study): A 6-week, multicenter, double-blind, randomized, 2-period,
placebo-controlled, parallel-group study of 1,992 patients conducted under in-house blinding procedures. Study medication was administered once daily at bedtime. Patients had positive skin test results to 2 or more indoor allergens.⁵

Study III (initial study): A 6-week, multicenter, double-blind, randomized, 2-period, placebo- and active-controlled, parallel-group study of 1,355 patients 15 years and older conducted under in-house blinding procedures. The primary end point of daytime nasal symptoms score during the first 4 weeks of treatment included nasal itching in addition to congestion, rhinorrhea, and sneezing. Study medication was administered once daily at bedtime. Patients had positive skin test results to at least 1 indoor allergen.⁶

Additional information on clinical studies for perennial allergic rhinitis:

The initial and pivotal clinical studies

The initial 6-week study (N=1,355) included SINGULAIR 10 mg, placebo, and an active control, cetirizine 10 mg. The primary analysis compared SINGULAIR with placebo; the study was not designed for statistical comparison between SINGULAIR and the active control. The primary end point was measured during the initial 4 weeks of the 6-week study and compared the mean change from baseline in daytime nasal symptoms score, which included nasal itching in addition to nasal congestion, rhinorrhea, and sneezing. The estimated difference between SINGULAIR (n=626) and placebo (n=609) was –0.04 with a 95% confidence interval (CI) of (–0.09, 0.01). The estimated difference between the active control (cetirizine n=120) and placebo was –0.10 with a 95% CI of (–0.19, –0.01). Compared with placebo, SINGULAIR showed a numerical, but not a statistical, improvement in the primary end point. (Study III)⁶

The pivotal study (N=1,992) was conducted using the average of these 3 symptoms (nasal congestion, rhinorrhea, and sneezing) as the composite symptoms for the primary end point (daytime nasal symptoms score). (Study II)⁵