Safety, Pharmacokinetics, and Pharmacodynamics of SD-101 in Healthy Normal Males

This is a Phase 1, randomized, single-blind, placebo-controlled study of five escalating dose
levels of SD-101 in healthy male volunteers. The objectives of the study are to assess the
safety, tolerability, pharmacokinetic profile, and pharmacodynamics of SD-101. Approximately
40 subjects will participate.

Once subjects have been consented, screened, and assigned to one of the dose levels of
SD-101, subjects will receive a single subcutaneous injection of either SD-101 or placebo
(PBS) in a ratio of 6:2.

Safety and tolerability will be evaluated by occurrence of adverse events, blood and urine
laboratory tests, physical examination findings, vital signs , and electrocardiogram
findings. Pharmacodynamics will be evaluated by levels of blood biomarkers and serum
cytokines, and flow cytometric cell counts. Pharmacokinetics will be evaluated by levels of
study drug in serum.

Inclusion Criteria:

- Signed, written, informed consent must be obtained from the subjects before any
study-specific procedures are performed.

- Subject must be male and 18 years of age or older.

- Subject must be willing to submit to a urine drug screen and agree to abstain from
alcohol, caffeine, and tobacco during the required stay in the Phase I Unit.

- Subject must be willing to abide by the rules of the Phase 1 Unit.

- Subjects whose sexual partners are of childbearing potential must agree to use an
effective method of birth control (i.e., chemical contraceptives, barrier plus
spermicide, intrauterine device) during the treatment phase and for 14 days post
treatment.

- Must be negative for Hepatitis B and C and human immunodeficiency virus (HIV).

Exclusion Criteria:

- Females.

- Clinically significant active, acute, or chronic illness.

- History of coagulation or bleeding disorders.

- Clinically significant chronic or recent (within 21 days of dosing) acute
gastrointestinal disorder with nausea, vomiting or diarrhea as a major symptom.

- Received any vaccine within 3 weeks of study entry or plans to be vaccinated within 6
weeks after study injection.

- History of significant cardiovascular or cerebrovascular disease.

- History of evaluation for autoimmune disease including systemic lupus erythematosus
(SLE), rheumatoid arthritis (RA), scleroderma or thyroiditis.

- Significant psychiatric illness that could potentially interfere with the assessments
during this study.

- Subjects who have had prior surgery or a major infection within 6 months of dosing.

- History of medications within 7 days of dosing, except vitamins and/or minerals.

- History of Gilbert's disease.