(C2013-0302) Safety and Efficacy of Escalating Doses of SAN-300 in Patients With Rheumatoid Arthritis

Inclusion Criteria:

1. Diagnosed with RA for ≥ 6 months according to American College of Rheumatology
(ACR)/European League Against Rheumatism (EULAR) Classification Criteria 2010

2. 18 to 75 years of age, inclusive, at the time of informed consent

3. Swollen joint count of ≥ 6 (66-joint count) and tender joint count of ≥ 6 (68-joint
count) at Screening and randomization

4. Inadequate response to therapy or discontinuation of therapy because of unacceptable
toxicity from at least one prior traditional or biologic disease-modifying
anti-rheumatic drug (DMARD)

5. Stable dose of methotrexate (≥ 15 mg/week and ≤ 25 mg/week) for ≥ 6 weeks before
randomization

Exclusion Criteria:

1. Functional Class IV as defined by ACR classification of functional status in RA

2. History of significant systemic involvement secondary to RA (e.g., vasculitis,
pulmonary fibrosis, or Felty's syndrome)

3. History of malignancy or carcinoma in situ within the 5 years before Screening or any
history of melanoma. Patients with history of excised or adequately treated
non-melanoma skin cancer are eligible

4. Evidence of clinically significant uncontrolled concurrent diseases such as
cardiovascular, endocrinologic, hematologic, hepatic, immunologic, metabolic,
urologic, pulmonary, neurologic, dermatologic, psychiatric, renal, and/or other major
diseases

5. History of recurrent clinically significant infections

6. Current active infection or serious local infection (e.g., cellulitis, abscess) or
systemic infection (e.g., pneumonia, septicemia) within 3 months before randomization

7. History of severe allergic or anaphylactic reactions to other biologic agents

8. History of allergies to murine protein

9. Surgery within 3 months before randomization (other than minor cosmetic surgery or
minor dental procedures) or plans for a surgical procedure during the Treatment
Period or Follow-up Period

10. History of tuberculosis or latent infection currently undergoing treatment

11. History of malaria

12. Treatment regimen with prednisone that is either over 10 mg/day (or equivalent dose
of another corticosteroid) or is not taken at a stable dose of ≤ 10 mg/day for at
least 4 weeks before randomization

13. Intra-articular corticosteroid injection(s) within 4 weeks before randomization

14. Any live immunization/vaccination, including against Herpes zoster, within 4 weeks
before randomization. Live vaccinations must also be avoided throughout the study

15. Abnormal laboratory value at Screening or Day -1 considered clinically significant

16. Positive for hepatitis C virus (HCV) antibody or hepatitis B surface antigen (HBsAg)

17. Positive for human immunodeficiency virus (HIV) antibody

18. History of tuberculosis or positive QuantiFERON®-TB Gold test (QFT)