Pure red cell aplasia associated with imatinib-treated FIP1L1-PDGFRA positive chronic eosinophilic leukemia

Imatinib-induced severe hematological toxicity: Prolonged myelosuppression resulting from extraordinary sensitivity in an old age

The advent of tyrosine kinase inhibitors (TKIs) has profoundly changed the therapeutic landscape of chronic myeloid leukemia (CML) in the chronic phase (CML-CP). Imatinib is the first-generation, and the first and as yet the most widely used TKI, and the recommended dose is 400 mg/day for treating CML-CP. Most patients tolerate this treatment well, and prolonged hematological toxicities have rarely been reported. In this manuscript, we report a newly diagnosed CML-CP patient who developed prolonged myelosuppression (lasting for more than three months) following only one week of imatinib at 400 mg/day as the solitary treatment. Imatinib was discontinued, and pancytopenia persisted, with a continuous decrease in hemoglobulin levels. After restoration of autologous hematopoiesis, reintroduction of imatinib at 100 mg/day resulted in recurrent myelosuppression, and subsequent treatment with imatinib at 50 mg/day achieved good hematological homeostasis. We hypothesized that extraordinary sensitivity resulted in severe and prolonged myelosuppression.

TKI-induced pure red cell aplasia: first case report of pure red cell aplasia with both imatinib and nilotinib

Tyrosine-kinase inhibitors (TKIs) represent the only hopes for long-term survival for patients with chronic myeloid leukaemia (CML) and gastrointestinal stromal tumours. Thus, uninterrupted use of TKIs is of importance in such patients. Pure red cell aplasia (PRCA) is a rare disorder, not previously known to be associated with TKIs. We present, to the best of our knowledge, the first case of a patient with CML who developed PRCA secondary to both imatinib and nilotinib. Although PRCA was controlled on withdrawal of TKI, TKI continuation in the patient with CML is important. So we treated him with prednisone, but his haemoglobin started to drop on resumption of imatinib. He was changed to nilotinib but again developed PRCA, which did not improve with steroids. We treated him with cyclosporine and were able to reintroduce nilotinib at a reduced dose without further complications. This case report makes physicians aware of this rare complication of TKIs and also provides encouragement that PRCA could be controlled and TKI continued.