A Study of Ruxolitinib vs Best Available Therapy (BAT) in Patients With Steroid-refractory Chronic Graft vs. Host Disease (GvHD) After Bone Marrow Transplantation (REACH3)

Inclusion Criteria:

- Have undergone allogeneic stem cell transplantation (alloSCT) from any donor source
(matched unrelated donor, sibling, haplo-identical) using bone marrow, peripheral
blood stem cells, or cord blood. Recipients of non-myeloablative, myeloablative, and
reduced intensity conditioning are eligible

- Evident myeloid and platelet engraftment: Absolute neutrophil count (ANC) > 1000/mm^3
and platelet count > 25,000/ mm^3

- Participants with clinically diagnosed moderate to severe cGvHD according to NIH
Consensus Criteria prior to randomization:

- Moderate cGvHD: At least one organ (not lung) with a score of 2, 3 or more organs
involved with a score of 1 in each organ, or lung score of 1

- Severe cGvHD: at least 1 organ with a score of 3, or lung score of 2 or 3

- Participants currently receiving systemic or topical corticosteroids for the treatment
of cGvHD for a duration of < 12 months prior to Cycle 1 Day 1 (if applicable), and
have a confirmed diagnosis of steroid-refractory cGvHD defined per 2014 NIH consensus
criteria irrespective of the concomitant use of a calcineurin inhibitor (CNI), as
follows:

- A lack of response or disease progression after administration of minimum
prednisone 1 mg/kg/day for at least 1 week, OR

- Disease persistence without improvement despite continued treatment with
prednisone at > 0.5 mg/kg/day or 1 mg/kg/every other day for at least 4 weeks, OR

- Increase to prednisolone dose to > 0.25 mg/kg/day after 2 unsuccessful attempts
to taper the dose

- Participant must accept to be treated with only one of the following BAT options on
Cycle 1 Day 1 (additions and changes are allowed during the course of the study, but
only with BAT from the following BAT options): extracorporeal photopheresis (ECP),
low-dose methotrexate (MTX), mycophenolate mofetil (MMF), mTOR inhibitors (everolimus
or sirolimus), infliximab, rituximab, pentostatin, imatinib, ibrutinib

Exclusion Criteria:

- Participants who have received 2 or more systemic treatment for cGvHD in addition to
corticosteroids ± CNI for cGvHD

- Patients that transition from active aGvHD to cGvHD without tapering off
corticosteroids ± CNI and any systemic treatment

* Patients receiving up to 30 mg by mouth once a day of hydrocortisone (i.e.,
physiologic replacement dose) of corticosteroids are allowed.

- Participants who were treated with prior JAK inhibitors for aGvHD; except when the
participant achieved complete or partial response and has been off JAK inhibitor
treatment for at least 8 weeks prior to Cycle 1 Day 1

- Failed prior alloSCT within the past 6 months from Cycle 1 Day 1

- Participants with relapsed primary malignancy, or who have been treated for relapse
after the alloSCT was performed

- Steroid refractory cGvHD occurring after a non-scheduled donor lymphocyte infusion
(DLI) administered for preemptive 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

- Any corticosteroid therapy for indications other than cGvHD at doses > 1 mg/kg/day
methylprednisolone or equivalent within 7 days of Cycle 1 Day 1