Safety Study of AMG 557 in Subjects With Lupus Arthritis

Inclusion Criteria:

- Diagnosis of SLE for at least 6 months as defined by the most recent American College
of Rheumatology criteria

- Presence of lupus related inflammatory arthritis with at least four tender and four
swollen joints; and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) ≥ 6
at screening;

- Other inclusion criteria may apply.

Exclusion Criteria:

- Presence or history of vasculitis, and presence or history of active lupus nephritis
requiring therapy within the last 3 years

- Any disorder (including psychiatric), condition, clinically significant disease,
disease activity related to SLE

- Positive for HIV antibodies, hepatitis B surface antigen or anti-HBc, or hepatitis C
antibodies

- Known residential exposure to an individual with tuberculosis or positive Quantiferon
test or PPD test at screening

- Men and women of reproductive potential, unwilling to practice a highly effective
method of birth control for the duration of the study

- Other exclusion criteria may apply