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.