A Study of Safety and Efficacy of CNTO 148 in Patients With Severe Persistent Asthma

This is a multicenter, randomized (the study medication is assigned by chance), double-blind (neither physician nor patient knows the treatment that the patient receives), placebo-controlled (an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical study), parallel-group (each group of patients will be treated at the same time), dose-ranging study to evaluate the efficacy and safety of CNTO 148. The study will consists of run-in phase (2 weeks), treatment period (52 weeks) and follow up period (24 weeks). The patients inhaled corticosteroids (ICS) medication will be standardized in the run-in phase and the treatment period contains first 24 weeks of treatment, the patients are required to remain on stable doses of concomitant corticosteroids (CS) medication (steroid stable phase). The steroid stable phase is followed by a 28-week steroid taper phase, during which a reduction of concomitant CS medication will be attempted. After completion of the study treatment, patients are to be followed for an additional 24 weeks. Patients will receive subcutaneous injections of 75, 150, or 300 mg of CNTO 148 or placebo every 4 weeks for 52 weeks followed 50,100, or 200 mg every 4 weeks through week 52. The safety of the patient will be monitored throughout the study.