A Study to Evaluate Safety of Multi-Dose MEDI-545 in Adult Patients With Dermatomyositis or Polymyositis

"MEDI-545 is supplied as a sterile liquid containing 0.75 mL of MEDI-545 solution at a concentration of 100 mg/mL in a 3 mL single-use glass vial.~Dosage, frequency and duration: MEDI-545 (0.3, 1.0, 3.0, or 10.0 mg/kg) will be administered via infusion over at least 60 minutes every 2 weeks for 26 weeks."

"Dosage form: Placebo is supplied as a sterile liquid containing a 0.75 mL solution in a 3 mL single-use vial.~Dosage, frequency and duration: Placebo (0.3, 1.0, 3.0, or 10.0 mg/kg) will be administered via infusion over at least 60 minutes every 2 weeks for 12 weeks.~Thereafter, subjects will receive MEDI-545, at the dose specified in the dose cohort they are assigned, every 2 weeks for an additional 12 weeks."