The purpose of this study is to evaluate efficacy of SCM-CGH in participants with steroid dependent/refractory chronic graft versus host disease (cGVHD) by measuring overall cGVHD response (complete response [CR] and partial response [PR] defined by National Institutes of Health [NIH] consensus development project criteria [2014]).

Inclusion Criteria:

• Subjects who are males or females aged >= 19 years, 40kg to 80kg in weight
• Steroid dependent/refractory chronic graft versus host disease (cGVHD) defined as the National Institutes of Health (NIH) criteria (2014) below at any time post-hematopoietic cell transplant (post-HCT):

Refractory disease, defined as, 1) when cGVHD manifestations progress despite the use of a regimen containing glucocorticoid (prednisolone at >=1 mg/kg/day for at least 2 weeks) or 2), 3) Persist without improvement despite continued treatment with glucocorticoid (prednisolone at >=0.5 mg/kg/day or 1 mg/kg every other day) for at least 4 weeks Dependent disease, defined as, 4), 5) when glucocorticoid (prednisolone doses greater than or equal to [>=] 0.25 milligram per kilogram per day (mg/kg/day)or >=0.5 milligram per kilogram (mg/kg) every other day) are needed to prevent recurrence or progression of manifestations as demonstrated by unsuccessful attempts to taper the dose to lower levels on at least 2 occasions, separated by at least 8 weeks.

• Participants must be receiving less than 3 systemic glucocorticoid therapies or other immunosuppressive therapies in addition to glucocorticoids for cGVHD for at least 4 weeks before Screening visit. The dose of steroids or Immunosuppressant must be stable for 14 days(2 weeks) prior to starting SCM-CGH or Placebo.
• Laboratory test sufficiency as follows; Absolute neutrophil count (ANC) ≥ 1,000 cells/mm3 Serum creatinine < 2 x upper limit of normal (ULN)

Exclusion Criteria:

• Active acute graft versus host disease (GVHD)
• Active infection with human immunodeficiency virus (HIV), hepatitis B virus, or hepatitis C virus (HCV)
• Uncontrolled underlying disease such as moderate or severe infections and hemorrhage
• Severe Heart failure (NYHA class III/IV), congestive heart failure or arrhythmia requiring treatment
• History of allogenic hematopoietic stem cell more than once
• Positive reaction of a Penicillin test at screening
• History of relapse of causative diseases (ALL, CML, CLL, AML, NHL, multiple myeloma e.t.c.) with hematopoietic stem cell transplantation or diagnosed with secondary malignant diseases after hematopoietic stem cell transplantation
• History of Anti-thymocyte globulin(ATG) for 2 weeks before Screening visit
• History of pulmonary embolism or deep venous thrombosis for 24 weeks before Screening visit