Methods for treating immune thrombocytopenia by administering (R)-2-[3-[4-amino-3-(2-fluoro-4-phenoxy-phenyl)pyrazolo[3,4-d]pyrimidin-1-yl]piperidine-1-carbonyl]-4-methyl-4-[4-(oxetan-3-yl)piperazin-1-yl]pent-2-enenitrile

A method for achieving a platelet count of at least 50,000/μL in a human patient with immune thrombocytopenia (ITP) in need thereof comprising administering to the human patient a therapeutically effective amount of at least one compound chosen from (R)-2-[3-[4-amino-3-(2-fluoro-4-phenoxy-phenyl)pyrazolo[3,4-d]pyrimidin-1-yl]piperidine-1-carbonyl]-4-methyl-4-[4-(oxetan-3-yl)piperazin-1-yl]pent-2-enenitrile and pharmaceutically acceptable salts thereof, once a day or twice a day for a treatment period, wherein the human patient has been identified as having a platelet count of less than 30,000/μL for two or more consecutive platelet counts prior to the start of the treatment period, wherein two of the two or more platelet counts were measured no sooner than 7 days apart in the 15 days prior to the start of the treatment period, and wherein the human patient has been identified as having at least one characteristic chosen from:

• a history of taking at least one prior ITP therapy prior to the start of the treatment period;
• and
• splenectomy prior to the start of the treatment period.