Inclusion Criteria:

- Adult males 18 years to 64 years of age;

- Good general health (as evidenced by no chronic conditions, normal physical exam,
vital signs within normal limits; laboratory evaluations within normal range)

- Signed and dated written informed consent form; and

- Willing to participate in all study activities and all requirements, including
effective contraception (viz., a double-barrier method) during the 7-day study
surveillance period.

Exclusion Criteria:

- Hematology, serum chemistry (exclusive of electrolytes), and urinalysis laboratory
test values >2 times upper limits of normal or anemia (hemoglobulin <11 g/dL),
leukopenia (total white blood count <3,000/µL or total neutrophils <1,500/ µL) or
thrombocytopenia (platelets <100,000/µL). Electrolytes and coagulation values
exceeding normal ranges are to be excluded.

- Body Mass Index (BMI) >35.

- Calculated creatinine clearance (by the Cockroft and Gault Formula) <70 mL/min, based
on age and gender.

- Positive HIV-1 or HIV-2 serology.

- Positive HCV serology and/or positive plasma HCV-RNA status.

- Positive HBsAg or HBcAb status.

- Solid or hematopoetic organ transplant recipient.

- Active illness or recent illness within 30 days of the first dose of study drug.

- History of any of the following: brain injury, neoplasm, chronic or migraine
headaches, cancer, meningitis or hydrocephalus.

- Usage of any prescribed, over-the-counter or illicit drug(s) within 30 days of study
drug administration. Use of herbal remedies and/or supplements at the discretion of
the Investigator.

- Unwilling to practice effective contraception during the study period.

- Participation in any clinical interventional trial within the previous 6 months.

- Positive drug urine screen.