RESUMO
BACKGROUND: The long-term effects of eltrombopag on bone marrow (BM) reticulin and/or collagen deposition in previously treated adults with chronic immune thrombocytopenia (ITP) were assessed. METHODS: Three BM biopsies were collected at baseline and after 1 and 2 years of eltrombopag treatment. Specimens were centrally processed, stained for reticulin and collagen, independently reviewed by 2 hematopathologists, and rated according to the European Consensus 0-3 scale of marrow fibrosis (MF). RESULTS: Of 162 patients enrolled, 93 completed all 3 protocol-specified BM biopsies. All patients with a baseline assessment were negative for collagen. Of 159 patients assessed at baseline, 150 (94%) had normal reticulin (MF-0) and 9 (6%) had minimally increased reticulin (MF-1). After 2 years, 83/93 patients (89%) with BM biopsies had MF-0, 10 (11%) had MF-1, and none had MF-2 or MF-3. Five out of 127 patients (4%) at 1 year and 1 out of 93 (1%) at 2 years had collagen deposition. None of the patients had clinical symptoms typical of BM dysfunction or abnormalities of clinical concern based on white blood cell count or peripheral blood smear. CONCLUSION: For most patients with chronic ITP, eltrombopag is not associated with clinically relevant increases in BM reticulin or collagen formation.
Assuntos
Benzoatos/administração & dosagem , Medula Óssea , Colágeno/metabolismo , Hidrazinas/administração & dosagem , Púrpura Trombocitopênica Idiopática , Pirazóis/administração & dosagem , Reticulina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Medula Óssea/metabolismo , Medula Óssea/patologia , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/metabolismo , Púrpura Trombocitopênica Idiopática/patologiaRESUMO
Thrombopoietin receptor agonists, which raise platelet counts in patients with chronic immune thrombocytopenia, may be associated with increases in bone marrow (BM) reticulin. Patients with chronic immune thrombocytopenia participating in the Eltrombopag Extended Dosing (EXTEND) study underwent BM biopsies to identify clinically relevant BM fibrosis-related increases. Specimens were centrally reviewed by 2 hematopathologists. Two hundred thirty-two biopsy specimens were collected from 117 patients treated for ≤5.5 years. Moderate to marked reticulin fibrosis was found in 2 patients. After withdrawing from the study, the biopsy of 1 patient reverted to normal. There were no other pathologic changes identified among on-treatment specimens, and no pattern of abnormal reticulin deposition associated with eltrombopag treatment was evident.