Study of the Bruton's Tyrosine Kinase Inhibitor in Subjects With Chronic Graft Versus Host Disease

Inclusion Criteria:

- Steroid dependent or refractory classic chronic GVHD disease.

- No more than 3 previous treatments for cGVHD.

- Receiving baseline systemic glucocorticoid therapy (at stable dose) for cGVHD at
study entry.

- Men and women ≥18 years old.

- Karnofsky performance status ≥60.

Exclusion Criteria:

- Known or suspected active acute GVHD.

- Current treatment with sirolimus AND either cyclosporine or tacrolimus.

- History of treatment with a tyrosine kinase inhibitor (eg, imatinib), purine analogs
or other cancer chemotherapy in the 4 weeks prior to starting study drug.

- Currently active, clinically significant cardiovascular disease.

- Uncontrolled infections not responsive to antibiotics, antiviral medicines, or
antifungal medicines or a recent infection requiring systemic treatment that was
completed ≤14 days before the first dose of study drug.

- Progressive underlying malignant disease including post-transplant
lymphoproliferative disease.

- History of other malignancy (not including the underlying malignancy that was the
indication for transplant)

- Concomitant use of warfarin or other Vitamin K antagonists

- Known bleeding disorders or hemophilia.

- History of stroke or intracranial hemorrhage within 6 months prior to enrollment.

- Known history of human immunodeficiency virus (HIV) or active with hepatitis C virus
(HCV) or hepatitis B virus (HBV).

- Concurrent use of a strong cytochrome P450(CYP) 3A inhibitor.