This study is to compare the efficacy and safety of ozarelix 15 mg given intramuscular (IM) 2 weeks apart on the improvement of symptoms and the duration of improvement for up to 6 months in men with Benign Prostatic Hypertrophy (BPH) who are over 50 years of age.

This study is to compare the improvement in symptom scores, peak flow rate and quality of life in men suffering from lower urinary tract symptoms (LUTS) secondary to Benign Prostatic Hypertrophy (BPH) following treatment with ozarelix. Ozarelix is compared to placebo and injections given 14 days apart. Patients are followed for 6 months and both safety and efficacy assessed at monthly visits. Additionally, the impact of treatment on erectile function, if any, as well as Prostate-Specific Antigen (PSA) and Testosterone levels will be monitored.

The screening period of 7 days. The duration of the study is 40 weeks, including a 28-day placebo run-in phase (eligible participants entered a placebo run-in phase in which placebo is administered twice over a 2 week period [Day -28 and Day -14] and participants are assessed to establish baseline values approximately 14 days following the second placebo injection), study drug is administered on Days 0 and 14 followed by 34 weeks of observation after the last dose of study drug.

Inclusion Criteria:

- All of the following questions must be answered "Yes" at Visit 1 in order for the participant to participate in the study.

• Is the participant at least 50 years old?
• Does the participant have clinical signs and symptoms consistent with BPH?
• Does the participant have an IPSS 13 at screening (prior to placebo run in)?
• Does the participant have a peak urinary flow rate (Qmax) of 4-15 milliliter/second (mL/sec) established on a voided volume of at least 125 mL?
• Is the participant willing to agree not to use any other approved or experimental pharmacologic BPH treatments including alpha blockers, 5-alpha reductase inhibitors, anti-cholinergic preparations or herbal preparations at any time during the study?

Exclusion Criteria: All of the following questions must be answered "No" at Visit 1 in order for the participant to participate in the study.

• Does the participant have a history of prostate cancer or a serum PSA >10 nanograms per milliliter (ng/mL)?
• Has the participant had prior prostate or bladder surgery, pelvic surgery (excluding hernia repair), pelvic radiation or lower urinary tract malignancy?
• Does the participant have a prevoid total bladder volume assessed by ultrasound > 550 mL?
• Does the participant have a residual urine volume > 350 mL by ultrasound?