{"entity":{"id":"fostamatinib","kind":"drug","name":"Fostamatinib","aka":["Fostamatinib Disodium","R788","R935788"],"tldr":"Fostamatinib is a tablet that blocks the enzyme SYK so the spleen stops destroying antibody-coated platelets; it is approved for chronic immune thrombocytopenia and was first trialled as a lymphoma drug.","summary":"Fostamatinib is an oral SYK inhibitor approved in the United States in 2018 for adults with chronic immune thrombocytopenia (ITP) who have not responded to a previous treatment. SYK sits downstream of the B-cell receptor and of Fc receptors, and fostamatinib was originally studied in B-cell lymphomas and chronic lymphocytic leukaemia, where responses were modest and the programme moved to autoimmune disease. Its place in cancer care is therefore supportive: managing immune-mediated low platelets, including in patients whose ITP accompanies lymphoid cancers. Hypertension, diarrhoea and raised liver enzymes are the main side effects.","status":"established","asOf":"2026-09-08","wikipedia":"https://en.wikipedia.org/wiki/Fostamatinib","links":[{"label":"Label (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=fostamatinib"},{"label":"Drugs@FDA NDA 209299","url":"https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=209299"}],"tags":["gap-fill","supportive-care"],"related":[],"cancers":["cll","dlbcl"],"sections":[],"technologies":["supportive-care","kinase-inhibitors"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["thrombocytopenia"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"brand":"Tavalisse","modality":"Oral spleen tyrosine kinase (SYK) inhibitor","mechanism":"A prodrug converted to R406, which inhibits SYK and so blocks the antibody-triggered destruction of platelets by macrophages in the spleen.","approvals":[{"region":"US","year":2018,"indication":"Chronic immune thrombocytopenia in adults with insufficient response to a previous treatment"}],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/fostamatinib/","neighbours":{"cancer":[{"id":"cll","kind":"cancer","name":"Chronic lymphocytic leukaemia","route":"/cancers/cll/"},{"id":"dlbcl","kind":"cancer","name":"Diffuse large B-cell lymphoma","route":"/cancers/dlbcl/"}],"section":[{"id":"supportive-care","kind":"section","name":"Supportive Care & Survivorship","route":"/fronts/supportive-care/"}],"technology":[{"id":"kinase-inhibitors","kind":"technology","name":"Small-molecule kinase inhibitors","route":"/technologies/kinase-inhibitors/"}],"term":[{"id":"thrombocytopenia","kind":"term","name":"Thrombocytopenia","route":"/terms/thrombocytopenia/"}]}}