Tamsulosin Hydrochloride (Page 6 of 8)

14. CLINICAL STUDIES

Four placebo-controlled clinical studies and one active-controlled clinical study enrolled a total of 2296 patients (1003 received tamsulosin hydrochloride capsules 0.4 mg once daily, 491 received tamsulosin hydrochloride capsules 0.8 mg once daily, and 802 were control patients) in the U.S. and Europe.

In the two U.S. placebo-controlled, double-blind, 13-week, multicenter studies [Study 1 (US92-03A) and Study 2 (US93-01)], 1486 men with the signs and symptoms of BPH were enrolled. In both studies, patients were randomized to either placebo, tamsulosin hydrochloride capsules 0.4 mg once daily, or tamsulosin hydrochloride capsules 0.8 mg once daily. Patients in tamsulosin hydrochloride capsules 0.8 mg once-daily treatment groups received a dose of 0.4 mg once daily for one week before increasing to the 0.8 mg once-daily dose. The primary efficacy assessments included: 1) total American Urological Association (AUA) Symptom Score questionnaire, which evaluated irritative (frequency, urgency, and nocturia), and obstructive (hesitancy, incomplete emptying, intermittency, and weak stream) symptoms, where a decrease in score is consistent with improvement in symptoms; and 2) peak urine flow rate, where an increased peak urine flow rate value over baseline is consistent with decreased urinary obstruction.

Mean changes from baseline to Week 13 in total AUA Symptom Score were significantly greater for groups treated with tamsulosin hydrochloride capsules 0.4 mg and 0.8 mg once daily compared to placebo in both U.S. studies (Table 3, Figures 2A and 2B). The changes from baseline to Week 13 in peak urine flow rate were also significantly greater for the tamsulosin hydrochloride capsules 0.4 mg and 0.8 mg once-daily groups compared to placebo in Study 1, and for the tamsulosin hydrochloride capsules 0.8 mg once-daily group in Study 2 (Table 3, Figures 3A and 3B). Overall there were no significant differences in improvement observed in total AUA Symptom Scores or peak urine flow rates between the 0.4 mg and the 0.8 mg dose groups with the exception that the 0.8 mg dose in Study 1 had a significantly greater improvement in total AUA Symptom Score compared to the 0.4 mg dose.

Mean total AUA Symptom Scores for both tamsulosin hydrochloride capsules 0.4 mg and 0.8 mg once-daily groups showed a rapid decrease starting at 1 week after dosing and remained decreased through 13 weeks in both studies (Figures 2A and 2B).

In Study 1, 400 patients (53% of the originally randomized group) elected to continue in their originally assigned treatment groups in a double-blind, placebo-controlled, 40-week extension trial (138 patients on 0.4 mg, 135 patients on 0.8 mg, and 127 patients on placebo). Three hundred twenty-three patients (43% of the originally randomized group) completed one year. Of these, 81% (97 patients) on 0.4 mg, 74% (75 patients) on 0.8 mg, and 56% (57 patients) on placebo had a response ≥25% above baseline in total AUA Symptom Score at one year.

(click image for full-size original)

* indicates significant difference from placebo (p-value ≤0.050).
B = Baseline determined approximately one week prior to the initial dose of double-blind medication at Week 0. Subsequent values are observed cases.
LOCF = Last observation carried forward for patients not completing the 13-week study.
Note: Patients in the 0.8 mg treatment group received 0.4 mg for the first week. Note: Total AUA Symptom Scores range from 0 to 35.

(click image for full-size original)

* indicates significant difference from placebo (p-value ≤0.050).
Baseline measurement was taken Week 0. Subsequent values are observed cases.
LOCF= Last observation carried forward for patients not completing the 13-week study.
Note: Patients in the 0.8 mg treatment group received 0.4 mg for the first week. Note: Total AUA Symptom Scores range from 0 to 35.

(click image for full-size original)

* indicates significant difference from placebo (p-value ≤0.050).
B = Baseline determined approximately one week prior to the initial dose of double-blind medication at Week 0.
Subsequent values are observed cases.
LOCF = Last observation carried forward for patients not completing the 13-week study.
Note: The uroflowmetry assessments at Week 0 were recorded 4 to 8 hours after patients received the first dose of double-blind medication. Measurements at each visit were scheduled 4 to 8 hours after dosing (approximate peak plasma tamsulosin concentration). Note: Patients in the 0.8 mg treatment groups received 0.4 mg for the first week.

(click image for full-size original)

* indicates significant difference from placebo (p-value ≤0.050).
Baseline measurement was taken Week 0. Subsequent values are observed cases.
LOCF = Last observation carried forward for patients not completing the 13-week study.
Note: Patients in the 0.8 mg treatment group received 0.4 mg for the first week. Note: Week 1 and Week 2 measurements were scheduled 4 to 8 hours after dosing (approximate peak plasma tamsulosin concentration).

All other visits were scheduled 24 to 27 hours after dosing (approximate trough tamsulosin concentration).