A Study Evaluating the Efficacy and Safety of Neihulizumab vs "Conventional Treatment" to Treat Sr-aGvHD

This current Phase II trial is a randomized, open label, controlled, multiple dose,
multi-centre study to study the clinical efficacy and safety of Neihulizumab vs
"Conventional Treatment" to treat steroid-refractory acute graft-vs-host disease (sr-aGvHD)
in patients undergoing allogeneic hematopoietic cell transplantation.

This study will enroll a minimum of 90 patients, approximately 60 in Neihulizumab treatment
arm and 30 in Conventional treatment control arm.

The primary objectives is to evaluate the efficacy of Neihulizumab treatment in patients
with steroid-refractory acute GvHD compared to "conventional treatment." The secondary
objectives are to investigate safety, pharmacokinetics, and immunogenicity of Neihulizumab
administration in subjects with steroid-refractory acute GvHD.

For safety evaluation, the parameters to be assessed are adverse events (AEs),
discontinuation of therapy due to AEs, safety laboratory analysis, ECG, vital signs,
physical examination, and immunogenicity.

Inclusion Criteria:

1. Patient must be ≥18years of age, males or females;

2. Patient must have been recipients of a single allogeneic HCT; bone marrow, peripheral
blood and/or umbilical cord blood recipients are allowed

3. Patients must have aGvHD without feature of classic chronic GvHD or overlap GvHD;

4. Patients must have received no prior treatment for aGvHD other than steroids;

5. Patients must have biopsy proven grade II to IV aGvHD progressing after at least 3
days, non-improving grade III to IV aGvHD persistent after at least 7 days, or
non-improving grade II aGvHD persistent after at least 14 days of methylprednisolone
2mg/kg/day or equivalent; Patients with initial response but have flare of aGvHD
within 14 days with methylprednisolone > 0.5 mg/kg/day or equivalent are also
eligible;

6. Patient must have an ANC of > 500/mm3 and no evidence of HCT graft failure or
multi-organ failure;

7. Patient must have Karnofsky Performance Status (KPS) ≥50%;

8. Patient must give informed consent and sign an approved consent form prior to any
study procedures;

9. Females of childbearing potential must have a negative pregnancy test result prior to
enrollment. Males and females of childbearing potential must agree to use a highly
effective method of birth control during the study.

Exclusion Criteria:

1. Uncontrolled infections not responsive to antimicrobial therapy or requiring
intensive critical care or vasopressors;

2. Evidence of end-organ infection due to CMV;

3. HIV infection or a known HIV-related malignancy (NOTE: patients positive for
hepatitis B or hepatitis C are not excluded, and may be evaluated on a case by case
basis).

4. Tuberculosis, history of tuberculosis or a known positive Quantiferon test for
tuberculosis

5. Donor lymphocyte infusion for residual or relapsed disease or mixed chimerism. DLI as
part of the planned HCT protocol are allowed

6. Relapsed disease after transplant or progressive malignant disease, including
post-transplant lymphoproliferative disease; any secondary malignancy diagnosed since
HCT

7. Renal failure requiring hemodialysis

8. Need ICU care, with life expectancy of less than 28 days, with ongoing or unresolved
veno-occlusive disease, with unstable hemodynamics, with evidence of current or
previous clinically significant disease, medical condition or finding of the medical
examination (including vital signs and ECG), that in the opinion of the Investigator,
would compromise the safety of the patient or the quality of the data

9. History of allergy/hypersensitivity to a systemically administered biologic agent or
its excipients

10. Pregnant or nursing