18. Prior treatment with a BTK inhibitor 19. Presence of transfusion-dependent thrombocytopenia or a history of bleeding disorders or clinical conditions (eg, gastrointestinal bleeding or constitutional disorders) that may increase risk of life-threatening bleeding when thrombocytopenic 20. History of stroke or intracranial hemorrhage within 6 months prior to signing the ICD 21. Medications that are strong inhibitors or inducers of CYP3A4/5 (eg, itraconazole, ketoconazole, clarithromycin, ritonavir, phenytoin, pentobarbital, and rifampin) should be changed; subjects who cannot change these medications must be excluded.