The purpose of this trial is to evaluate the dose response relationship of lonidamine and the primary efficacy endpoint, International Prostate Symptom Score (IPSS), in subjects with symptomatic benign prostatic hyperplasia (BPH).

Inclusion Criteria:

1. Capable of understanding the purpose and risks of the study and sign a statement of informed consent
2. Male 65-80 years of age (or 40-80 with vasectomy). Vasectomized men must have documentation of azoospermia.
3. Presence of LUTS (lower urinary tract symptoms) for at least 3 months
4. Prostate volume measured by TRUS (transrectal ultrasound) > 30 cc
5. Qmax < 15 mL/sec when measured by uroflowmetry (minimum of 125 mL must be voided)
6. IPSS (International Prostate Symptom Score) > 12
7. PSA > 1.0 ng/mL
8. Must ensure and consent to use medically acceptable methods of contraception throughout the entire study with sexual partners of childbearing potential
9. Able to comply with the prescribed treatment protocol and evaluations

Exclusion Criteria:

1. Prior treatment for BPH with alpha blockers and/or herbal supplements for the treatment of BPH in the past 2 weeks (alpha-blockers and/or herbal supplements for the treatment of BPH are not allowed during the study). Prior treatment with 5-alpha reductase inhibitors is allowed if discontinued at least 3 months prior to enrollment.

2. Prior surgery of the prostate (except biopsies; subject is eligible to enroll one month after full recovery from prostate biopsy.)

3. Current or past evidence of malignant disease of the prostate or prostatic intraepithelial neoplasia (For subjects with PSA between 4 - 10 ng/mL, prostate cancer must be ruled out to the satisfaction of the Principal Investigator. Subjects with PSA >10 ng/mL are excluded).

4. Active urinary tract infections (UTI)

5. Active cardiac, renal or hepatic disease as evidenced by:

   1. Serum creatinine > 1.8 mg/dL
   2. ALT or AST > 2.5x the upper limit of normal
   3. History of active myocardial infarction, unstable cardiac arrhythmias, or stroke within 6 months prior to screening
   4. Uncontrolled congestive heart failure

6. Uncontrolled diabetes mellitus (fasting blood glucose > 200 mg/dL)

7. Use of systemic steroids for any reason (systemic steroid usage is not allowed during the study). Inhaled and/or topical steroids are allowed.

8. Concurrent participation or participation in an investigational drug study within the past 30 days prior to screening

9. Concomitant disease or condition that could interfere with the conduct of the study, or would in the opinion of the Investigator, pose an unacceptable risk to the subject