After re-confirming the eligibility of patients at Visit 2, eligible patients will be randomly assigned to either treatment group or control group in a 2:1 ratio. In addition, patients in the treatment group will receive ENIA11 25 mg twice weekly by subcutaneous injection while patients in the control group will receive placebo solution twice weekly by subcutaneous injection from Day 0 to week 12 and then switch to active drug from week 12 to week 24 and follow up period of 2 weeks.