Study of orBec® as Monotherapy in the Treatment of Patients With Upper GI Symptoms Caused by Chronic Graft Versus Host Disease (GVHD)

Inclusion Criteria: * Receipt of allogeneic hematopoietic cell transplant \>100 days prior to consent * Documented cGVHD as defined by the NIH consensus criteria in at least one organ system other than the GI tract (for example, cGVHD of the oral cavity would qualify as a criterion) * Endoscopic findings consistent with GI GVHD * Must be able to swallow tablets * Must be able to read and understand informed consent * Adequate birth control methods for the duration of the study Exclusion Criteria: * \>500 mL/day of diarrhea on any 1 day within 3 days prior to the first dose of study drug * GI infection * Multi-organ failure or other condition that, in the opinion of the investigator, would compromise the patient's ability to complete the study. * HIV seropositivity * Pregnant or nursing female * Use of any investigational drug to treat chronic GVHD within 28 days of the first dose of study drug * Evidence of recurrent or progressing malignant disorder that was the indication for HCT