A Study in Erectile Dysfunction

• Sexual Encounter Profile Diary Question Number 1, Change From Baseline to Post Baseline During the Double-blind Period in Percentage of Yes Responses [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the mean change from baseline in the percentage of "yes" responses to the Sexual Encounter Profile Diary question number 1: "Were you able to achieve at least some erection (some enlargement of the penis)"? Data are presented as the mean percentage of participants who answered "yes".
• Sexual Encounter Profile Diary Question Number 2, Change From Baseline to Post Baseline During the Double-blind Period in Percentage of Yes Responses [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the mean change from baseline in the percentage of "yes" responses to the Sexual Encounter Profile Diary question number 2: "Were you able insert your penis into your partner's vagina?" Data are presented as the mean percentage of participants who answered yes.
• Sexual Encounter Profile Diary Question Number 3, Change From Baseline to Post Baseline During the Double-blind Period in Percentage of Yes Responses [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the mean change from baseline in the percentage of "yes" responses to the Sexual Encounter Profile Diary question number 3: "Did your erection last long enough for you to have successful intercourse?" Data are presented as the mean percentage of participants who answered "yes".
• Sexual Encounter Profile Diary Question Number 4, Change From Baseline to Post Baseline During the Double-blind Period in Percentage of Yes Responses [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the mean change from baseline in the percentage of "yes" responses to the Sexual Encounter Profile Diary question number 4: "Were you satisfied with the hardness of your erection?" Data are presented as the mean percentage of participants who answered "yes".
• Sexual Encounter Profile Diary Question Number 5, Change From Baseline to Post Baseline During the Double-blind Period in Percentage of Yes Responses [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the mean change from baseline in the percentage of "yes" responses to the Sexual Encounter Profile Diary question number 5: "Were you satisfied overall with this sexual experience?" Data are presented as the mean percentage of participants who answered "yes".
• Sexual Encounter Profile Diary Question 3, the Overall Distribution of Time to Onset by Yes Responses [ Time Frame: 4 days double-blind period ] [ Designated as safety issue: No ]
  Assessed was the median time to onset of efficacy (day when 50% of participants have had at least 1 successful intercourse attempt) within the first 4 days of therapy based on a "yes" response to the sexual encounter profile diary question 3: "Did your erection last long enough for you to have successful intercourse?" Data are based on participants who responded "yes". For the placebo group, onset of efficacy was not reached within the first 4 days of therapy, therefore, the analysis timeframe was expanded for this group to determine the median time to onset of efficacy.
• Sexual Encounter Profile Diary Question 3, Daily Cumulative Percentage of Successful Intercourse Attempts [ Time Frame: 14 days during double-blind period ] [ Designated as safety issue: No ]
  Assessed was the cumulative precentage of successful intercourse attempts (successful attempts relative to the total number of intercourse attempts) over the 14-day double-blind treatment period. A successful attempt was defined by a "yes" response to the sexual encounter profile diary question #3: "Did your erection last long enough for you to have successful intercourse?" Data are presented as the proportion of intercourse attempts for which participants answered "yes" relative to the total number of intercourse attempts. Total number of attempts = TNA.
• Sexual Encounter Profile Diary Question 3, Percentages of Yes Responses During the Double-blind and Open-label Periods for Participants Who Were Assigned to Placebo in the Double-blind Treatment Period [ Time Frame: 14 days double-blind and 14 days open-label ] [ Designated as safety issue: No ]
  Assessed were percentages of successful intercourse attempts relative to the total number of intercourse attempts over the 14-day open-label treatment period compared with the 14-day double-blind treatment period by dose group during the double-blind treatment period. A successful attempt was defined by a "yes" response to the sexual encounter profile diary question #3: "Did your erection last long enough for you to have successful intercourse?"
• Sexual Encounter Profile Diary Question 3, Percentages of Yes Responses in the Double-blind Period and the Open-label Period for Participants Who Were Assigned to Tadalafil 2.5 mg in the Double-blind Treatment Period [ Time Frame: 14-day double-blind and 14-day open-label ] [ Designated as safety issue: No ]
  Assessed were percentages of successful intercourse attempts relative to the total number of intercourse attempts over the 14-day open-label treatment period compared with the 14-day double-blind treatment period by dose group during the double-blind treatment period. A successful attempt was defined by a "yes" response to the sexual encounter profile diary question #3: "Did your erection last long enough for you to have successful intercourse?"
• Sexual Encounter Profile Diary Question 3, Percentages of Yes Responses in the Double-blind Period and the Open-label Period for Participants Who Were Assigned to Tadalafil 5 mg in the Double-blind Treatment Period [ Time Frame: 14-day double-blind and 14-day open-label ] [ Designated as safety issue: No ]
  Assessed were percentages of successful intercourse attempts relative to the total number of intercourse attempts over the 14-day open-label treatment period compared with the 14-day double-blind treatment period by dose group during the double-blind treatment period. A successful attempt was defined by a "yes" response to the sexual encounter profile diary question #3: "Did your erection last long enough for you to have successful intercourse?"
• Sexual Encounter Profile Diary Question 3, Percentages of Yes Responses During the Double-blind Period and the Open-label Period for Participants Who Didn't Respond to Tadalafil 2.5 mg During Double-blind Period [ Time Frame: 14 days double-blind and 14 days open-label ] [ Designated as safety issue: No ]
  Assessed were percentages of successful intercourse attempts relative to the total number of intercourse attempts in both treatment periods. A successful attempt was defined by a "yes" response to the sexual encounter profile diary question #3: "Did your erection last long enough for you to have successful intercourse?"

• Sexual Encounter Profile Diary question number 1, change from baseline to post baseline during the double-blind period in percentage of "yes" responses. [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question number 2, change from baseline to post baseline during the double-blind period in percentage of "yes" responses. [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question number 3, change from baseline to post baseline during the double-blind period in percentage of "yes" responses. [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question number 4, change from baseline to post baseline during the double-blind period in percentage of "yes" responses. [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question number 5, change from baseline to post baseline during the double-blind period in percentage of "yes" responses. [ Time Frame: Baseline and 14 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question 3, the overall distribution of time to onset by "yes" responses [ Time Frame: 4 days double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question 3, daily cumulative proportion of successful intercourse attempts [ Time Frame: 14 days during double-blind period ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question 3, change from baseline to post baseline during the open-label period in percentage of "yes" responses by previous double-blind treatment assignment. [ Time Frame: 14 days double-blind and 14 days open-label ] [ Designated as safety issue: No ]
• Sexual Encounter Profile Diary question 3, change from baseline to post baseline during the open-label period in percentage of "yes" responses for patients who didn't respond to tadalafil 2.5 mg during double-blind period [ Time Frame: 14 days double-blind and 14 days open-label ] [ Designated as safety issue: No ]

The purpose of this study is to determine the day of onset of efficacy of tadalafil dosed once-a-day.

• Drug: Placebo
  One tablet orally daily
• Drug: Tadalafil
  Orally once daily
  Other Names:

  • Cialis
  • LY450190

• Experimental: Tadalafil 2.5 mg
  No drug during baseline period, 2.5 mg for 14 days, then will continue at 5 mg for 14 days.
  Intervention: Drug: Tadalafil
• Experimental: Tadalafil 5 mg
  No drug during baseline period, 5 mg for 14 days, then will continue at 5 mg for 14 days.
  Intervention: Drug: Tadalafil
• Placebo Comparator: Placebo
  No drug during baseline period, placebo for 14 days, then will continue tadalafil at 5 mg for 14 days.
  Interventions:

  • Drug: Placebo
  • Drug: Tadalafil

Inclusion Criteria:

• Male and at least 18 years old, with at least a 3-month history of erectile dysfunction (ED).
• Anticipate having same adult female sexual partner during the study.
• Agree to make at least 4 sexual intercourse attempts with the female partner during the 4-week run-in phase without medication.
• Agree to make at least 1 sexual intercourse attempt per day with the female partner during days 1-4 following randomization (with a minimum of three attempts required during that period). Also agree to make at least 3 intercourse attempts during days 5-14 following randomization.
• Agree not to use any other ED treatment during the study and for 24 hours after the final study visit.

Partner Inclusion Criteria:

• Female and at least 18 years old.
• Agree to make at least 4 sexual intercourse attempts with the male sexual study partner during the 4-week run-in phase without medication.
• Agree to make at least 1 sexual intercourse attempt per day with the male partner during days 1-4 following randomization
• Agree to make at least 3 intercourse attempts during days 5-14 following randomization.

Exclusion Criteria:

• Previous or current treatment with tadalafil or any phosphodiesterase type 5 (PDE5) inhibitor on a daily basis for once daily use.
• ED caused by other primary sexual disorders, or untreated or inadequately treated endocrine disease.
• History of radical prostatectomy, other pelvic surgery or penile implant.
• Clinically significant penile deformity in the opinion of the investigator.
• Clinically significant renal insufficiency, or hepatobiliary disease as determined by the investigator.
• Glycosylated hemoglobin of >11%.
• Present with chronic stable angina treated with long-acting nitrates, or with chronic stable angina requiring short-acting nitrates in the last 90 days, or with angina occurring during sexual intercourse in the last 6 months.
• Have any significant cardiac conditions as described in the protocol exclusion criteria.
• Have a history of significant central nervous system injuries within the last 6 months.
• Have a history of Human Immunodeficiency Virus infection.
• Have any condition that would interfere with the subject's ability to provide informed consent or comply with study instructions, would place subject at increased risk, or might confound the interpretation of the study results.
• Currently receive treatment with nitrates, cancer chemotherapy, or antiandrogens (except finasteride taken as Propecia or Proscar, or Avodart [dutasteride]).
• History of drug, alcohol, or substance abuse within the past 6 months, as assessed by the investigator.
• Previously completed or withdrawn from any other study investigating tadalafil for once daily use.
• Received treatment within the last 30 days with a drug that has not received regulatory approval for any indication at the time of study entry.
• Prior ineffective treatment with any PDE5 inhibitor in the opinion of the investigator.