A Study of AbGn-168H in Patients With Steroid Refractory Acute Graft-vs-Host Disease After Donor Stem Cell Transplant

Inclusion Criteria: 1. Diagnosis of skin, gut and/or liver steroid-refractory GVHD by clinical assessment of treating physician following allogeneic HCT. Patients who fail to respond to steroids by 7 days are considered steroid-refractory 2. Previously-treated with any conditioning regimen and any GVHD immune suppression prophylaxis and formulation of steroids, except as noted in Exclusion Criteria #2. 3. AbGn-168H (neihulizumab) therapy can begin not more than 14 days after diagnosis of aGvHD 4. Karnofsky Performance Status (KPS) \> 50% 5. No evidence of HCT graft failure or multi-organ failure 6. Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: 1. Uncontrolled infections not responsive to antimicrobial therapy requiring intensive critical care 2. Progressive malignant disease, including post-transplant lymphoproliferative disease unresponsive to therapy 3. Treatment with investigational GVHD prophylactic agents (eg, CCR5 inhibitors; lenalidomide; and/or bortezomib) within the 7 days prior to the 1st dose of neihulizumab 4. Treatment with other investigational agents within the prior 7 days prior to the 1st dose of AbGn-168H (neihulizumab) 5. CMV PCR \> 500 copies/mL or evidence of end-organ damage due to CMV 6. Pregnant or nursing 7. HIV positivity (NOTE: patients positive for hepatitis B or hepatitis C are not excluded, and may be evaluated on a case-by-case basis) 8. Renal clearance CCR \< 40 mL/min