GRAVITAS-309: Itacitinib or Placebo in Combination With Corticosteroids as Initial Treatment for Chronic Graft-Versus-Host Disease

Inclusion Criteria:

- Active, clinically diagnosed, moderate or severe cGVHD per NIH Consensus Criteria

- Underwent allogeneic stem cell transplantation (allo-HCT) from any donor human
leukocyte antigen (HLA) type (matched-related, matched-unrelated, or mismatched
related or unrelated donor) using any graft source (bone marrow, peripheral blood stem
cells, or cord blood). Recipients of myeloablative or reduced intensity conditioning
are eligible.

- Karnofsky Performance Status score ≥ 60%.

- Evidence of myeloid and platelet engraftment (ie, absolute neutrophil count ≥ 1.0 ×
10^9/L and platelet count ≥ 25 × 10^9/L).

- Willingness to avoid pregnancy or fathering children based on protocol-defined
criteria.

Exclusion Criteria:

- Has received more than 3 days/72 hours of systemic corticosteroid treatment for cGVHD.

- Has received any other systemic treatment for cGVHD, including extracorporeal
photopheresis (ECP). Prior and concomitant use of calcineurin inhibitors as well as
topical/inhaled steroids is acceptable.

- Prior treatment with a Janus kinase (JAK) inhibitor for acute GVHD, unless the
participant achieved complete or partial response and has been off JAK inhibitor
treatment for at least 8 weeks before randomization.

- cGVHD occurring after a nonscheduled donor lymphocyte infusion (DLI) administered for
pre-emptive treatment of malignancy recurrence. Participants who have received a
scheduled DLI as part of their transplant procedure and not for management of
malignancy relapse are eligible.

- Evidence of relapsed primary malignancy or receipt of treatment for relapse after the
allo-HCT was performed.

- Corticosteroid therapy at doses > 0.25 mg/kg per day methylprednisolone or equivalent
within 7 days of randomization.