A Study to Evaluate the Safety, Tolerability, PK, PD, and Clinical Activity of EQ001 in Subjects With aGVHD

The study will enroll approximately 100 subjects in two (2) parts:

Part A is an open label study and will enroll approximately 40 evaluable subjects with aGVHD across 4 cohorts. The total number of patients will depend on the number of dose escalations necessary to enable a decision to be made on the recommended dose to take forward into Part B of the study. The planned dose escalation will start with cohort 1, where subjects will receive EQ001 administered intravenously every two weeks for a total of 5 doses.

Part B is a randomized, double-blind, placebo-controlled study and will enroll approximately 60 additional subjects, randomized in a 2:1 ratio to either active treatment EQ001 (40) or placebo (20). Subjects will receive either EQ001 or placebo administered intravenously every two weeks for a total of 5 doses.

Inclusion criteria

• Male or female subject at least 18 years of age for Part A, and at least 12 years of age for Part B.
• Recipients of allogeneic hematopoietic stem cell transplantation (alloHSCT) using myeloablative or non myeloablative conditioning regimens.
• Have a clinical diagnosis of acute GVHD requiring systemic immune suppressive therapy.
• Deemed by the investigator to be likely to comply with the planned procedure as required by the protocol for the duration of the study

Exclusion criteria

• Presence of morphologic relapsed primary malignancy, treatment for relapse after alloHSCT was performed, or requirement for rapid immunosuppressive treatment withdrawal for early malignancy relapse.
• Evidence of graft failure based on cytopenia(s), and as determined by the investigator.
• Evidence of post-transplant lymphoproliferative disease.
• Any prior therapy for acute GVHD, except for alloHSCT prophylaxis regimens or systemically administered corticosteroids.
• As determined by the investigator, any medical, psychiatric, or other condition or circumstance that is likely to negatively affect: the subject's participation in this clinical study, the subject's safety, or the reliability of the study data.