Infusion of peripheral blood stem cells collected at diagnosis, with maintenance of the treatment, resulted in Ph-negative recovery in a chronic myeloid leukaemia patient in persisting aplasia on STI-571 therapy

Severe bone marrow aplasia following imatinib mesylate in a patient with chronic myelogenous leukemia

Imatinib mesylate, a signal transduction inhibitor molecule, has been introduced in the treatment of chronic myelogenous leukemia (CML) since May 2001. By its unique mechanism of action, the drug has revolutionized the management of chronic phase CML. The drug is generally well tolerated. A number of hematological and non-hematological side-effects have been reported. Fatal bone marrow (BM) aplasia has rarely been reported. A 46-year-old women with chronic phase CML was treated with imatinib. Six weeks later she developed severe pancytopenia associated with fever, chest infection and bleeding. A BM biopsy revealed hypoplasia (BM cellularity < 5%). She died of pulmonary mucormycosis. CML patients on imatinib therapy need close monitoring. Those pre-treated with busulfan and interferon-alpha may be at a higher risk of developing BM aplasia.

Myelosuppression in patients benefiting from imatinib with hydroxyurea for recurrent malignant gliomas

Reports suggest reasonable efficacy and minimal myelosuppression from combination imatinib and hydroxyurea for recurrent malignant glioma. We retrospectively reviewed 16 patients treated with this regimen who were evaluable for toxicity; 14 were also evaluable for response. The incidence of grade 3-4 hematologic toxicity was 25%. The best radiographic response, by Macdonald criteria, was partial response (PR) in three patients (21%), stable disease (SD) in four (29%), and progressive disease (PD) in seven (50%). One patient with a PR developed therapy-limiting hematologic toxicity on day 19 of treatment, progressing to grade 4 on day 64, and persisting until death on day 127 despite discontinuing both drugs. Another patient with PR and two of four patients with SD also developed grade 3 hematologic toxicity. All patients with grade 3-4 hematologic toxicity had disease control (PR or SD) as best radiographic response, whereas none with PD suffered grade 3-4 hematologic toxicity. Combining imatinib with hydroxyurea is effective in some patients with malignant glioma. However, myelosuppression can persist for months after discontinuing the regimen, precluding further chemotherapy. Disease control may also correlate with hematologic toxicity (p = 0.08), suggesting that glioma and marrow stem cells may share a common sensitivity to this chemotherapy regimen.