A Study of LY900010 in Erectile Dysfunction

Inclusion Criteria include: * Ambulatory men * History of erectile dysfunction of at least 3 months duration * History of incomplete response to any phosphodiesterase type 5 inhibitor (PDE5i) at the maximum tolerated dose within the label * Anticipate having the same female sexual partner throughout the duration of the study * Are willing and able to make at least 4 sexual intercourse attempts with the female sexual partner during each 4-week segment of the study * Agree to use birth control during the study and for 60 days after the study, unless the female partner is postmenopausal * Agree not to use any other erectile dysfunction treatment, including herbal treatment, during the study and for 96 hours after the last dose of study drug * Screening laboratory tests within normal limits except for testosterone * Without a language barrier, are reliable and willing to follow study procedures * Prostate-specific antigen (PSA) less than 10 nanograms per milliliter (ng/ml). Men with PSA greater than 4 and less than 10 ng/ml must have documentation of a negative histological biopsy of carcinoma of prostate within 12 months prior to screening Exclusion Criteria include: * History of penile implant * History of no response to injection therapy for erectile dysfunction * History of radical prostatectomy or other pelvic surgery with subsequent failure to achieve any erection * Exhibit the presence of clinically significant penile deformity in the opinion of the investigator * History of prior sexual legal convictions * Bilateral hip replacements * History of cancer within the previous 5 years, except for excised superficial lesions such as basal cell carcinoma and squamous cell carcinoma of the skin * Chronic stable angina currently treated with long-acting nitrates * Chronic stable angina requiring treatment with short-acting nitrates within 90 days prior to screening * Angina occurring during sexual intercourse in the 6 months prior to screening * Unstable angina within 6 months prior to screening * Myocardial infarction or coronary artery bypass graft surgery within 90 days prior to screening * Angioplasty or stent placement within 90 days prior to screening * Congestive heart failure within 6 months prior to screening * History of sudden cardiac arrest * Supraventricular arrhythmia with an uncontrolled ventricular response at rest, or any history of spontaneous or induced sustained ventricular tachycardia, or use an automatic internal cardioverter-defibrillator * An abnormality in the 12-lead electrocardiogram (ECG) that in the opinion of the investigator places the subject in an unacceptable risk for study participation * Systolic blood pressure greater than 170 or less than 90 millimeters of mercury (mm Hg) or diastolic blood pressure greater than 100 or less than 50 mm Hg at screening * Hepatic, renal, human immunodeficiency virus (HIV), or clinically significant active neuropsychiatric disease * History of central nervous system injuries (including stroke or spinal cord injury) within 6 months prior to screening * Alcohol intake of 5 units or greater per day (1 unit = 12 ounces beer, 5 ounces wine, or 1.5 ounces of 80-proof distilled spirits) * Receiving treatment with antiandrogens or 5-alpha reductase inhibitor * Anabolic steroids, calcitonin, oral bisphosphonates, Vitamin D greater than 50,000 international units per week (IU/week), dehydroepiandrosterone (DHEA), steroidal supplements, nutritional products intended to have weight reduction or performance enhancing effects, herbal supplements within 7 days prior to screening * Currently treated with a potent cytochrome P450 (CYP) 3A4 inhibitor, such as systemic ketoconazole or ritonavir, or a CYP3A4 inducer such as rifampicin