An Open-label Study to Evaluate the Long-term Safety of MEDI-546, for the Treatment of SLE, in Adults

This is an open-label extension study to evaluate long-term safety and tolerability of
intravenous (IV) MEDI-546 in adult subjects with moderately-to-severely active systemic lupus
erythematosus (SLE). Subjects must have completed the qualifying Phase 2 study and meet this
study criteria in order to be eligible.

Inclusion Criteria:

- Must be willing to use 2 methods of effective contraception

- Must have venous access

- Must be willing to forego participation in other clinical trials for SLE.

Exclusion Criteria:

- Any concurrent condition that in the opinion of the investigator would interfere with
the evaluation of the investigational product

- Major surgery within 8 weeks before signing ICF

- Elective major surgery planned during the study period

- Concomitant Medications within the last 12 weeks: Azathioprine > 200 mg/day,
Mycophenolate mofetil/mycophenolic acid > 2.0 g/day, Oral, SC, or intramuscular
methotrexate > 25 mg/week

- A live or attenuated vaccine within 4 weeks of signing the ICF

- Bacillus of Calmette and Guérin (BCG) vaccine within 1 year of ICF