Sudden blastic transformation in patients with chronic myeloid leukemia treated with imatinib mesylate

Sudden blastic transformation (SBT) has been reported in 0.5% to 2.5% of patients treated with interferon-alpha (IFN-alpha) during the first 3 years of therapy. Imatinib is now standard therapy for patients with chronic myeloid leukemia in chronic phase. We investigated the occurrence of SBT among patients treated with imatinib. Among 541 patients treated with imatinib in chronic phase, 23 developed blast phase, which was of sudden onset (ie, occurring in patients previously in complete cytogenetic remission) in 4 patients (17%; 0.7% of the total), 2 lymphoid and 2 myeloid. Patients with SBT were found to have low-risk features more often at the time of presentation and had achieved optimal response with imatinib. Three of the 4 patients underwent allogeneic stem cell transplantation and achieved a molecular remission. SBT is still a rare event, probably less common than that observed with IFN-alpha therapy. Continuous monitoring of patients treated with imatinib is mandatory.     

Efficacy and prognosis of chronic myeloid leukemia treated with imatinib mesylate in a Chinese population

There is limited data from developing countries on the current status of imatinib treatment for chronic myeloid leukemia (CML), thus we retrospectively analyzed 116 Chinese CML patients who received imatinib between 2003 and 2008. The response rates for 102 patients in chronic phase were: complete hematologic, 94.1%; complete cytogenetic, 69.6%; and complete molecular response, 54.9%. For 14 patients in the accelerated phase, the respective response rates were 85.7, 35.7 and 28.6%. The 3-year progression-free survival and 5-year overall survival were 73.3 and 74.8%. Although skin hypopigmentation occurs as the most common side effect (77.6%), imatinib is still well tolerated. In addition to the known pretreatment characteristics of spleen size, leukocyte and platelet counts, disease phase and Sokal scores, we found that delayed therapy, variant Philadelphia chromosome translocations and IM-related grade 3/4 leucopenia were associated with an inferior cytogenetic response. Four factors emerged as predictors of disease progression: molecular response, cytogenetic response, disease phase and disease duration prior to imatinib treatment, but only the latter three remained significant after multivariate analysis. The results indicate that the suboptimal outcome in Chinese patients is associated with delayed imatinib therapy, so the importance of the optimal treatment opportunity for CML should be emphasized.     

Factors predicting molecular and cytogenetic response in chronic myeloid leukemia patients treated with imatinib

We studied 94 clinically heterogeneous chronic myeloid leukemia (CML) patients and found that the duration of treatment with interferon-alpha (IFN-alpha) prior to imatinib therapy may not improve response to imatinib for patients in chronic phase but a shorter period between CML diagnosis and the initiation of imatinib is predictive for a better molecular response to therapy (p<0.05).     

Two successful pregnancies in a woman with chronic thrombotic thrombocytopenic purpura treated by plasma infusion

A 21-year-old primigravida in her 20th week of pregnancy developed TTP. She was managed with weekly or semiweekly plasma infusions and delivered a healthy 1.6 kg baby 2 weeks prior to the expected date of delivery. After delivery she continued to have active TTP with thrombocytopenia which responded repeatedly to plasma infusion though their frequency gradually decreased to about one unit every 3-4 weeks. Three years after the birth of the first child she conceived again and was easily managed with repeated plasma infusions although the frequency and amount of plasma required to prevent thrombocytopenia were increased. She delivered a normal 3.4 kg term baby after which she again had a decreased plasma requirement. This is the first report of a woman with 5 years of active TTP managed with plasma alone. She experienced two pregnancies in which both mother and infant survived. We believe that the use of plasma in the management of TTP during pregnancy will improve the survival rate of both mother and infant. At the time of second birth, the platelet count was low in the mother but normal in the baby. This suggests that the platelet depressing factor of this patient does not cross the placental barrier.     

Pancreatic enzyme elevation in chronic myeloid leukemia patients treated with nilotinib after imatinib failure

An increase in the serum concentration of pancreatic enzymes (amylase and lipase) was reported in a proportion of imatinib-resistant and/or intolerant Philadelphia-positive chronic myeloid leukemia patients treated with nilotinib. Acute pancreatitis was very rare, and the relevance of these laboratory alterations remains unknown. We report on 8 chronic myeloid leukemia patients who developed serum lipase/amylase elevation during treatment with nilotinib. After a median follow-up of 26 months, none of these patients developed an acute pancreatitis or clinical signs of pancreatic disease. Pancreatic hyperenzymemia never led to permanent drug discontinuation and required nilotinib temporary interruption in one case only. The median cumulative duration of dose interruptions and response to treatment were comparable in patients with or without pancreatic enzyme elevation. The mechanisms of action of nilotinib on pancreatic enzymes deserves to be investigated: however, in our experience, the relevance of pancreatic hyperenzymemia was clinically very limited.     

Generalized erythema triggered by a rapid decrease of basophils in chronic myeloid leukemia treated with imatinib

A 57-year-old woman with chronic myeloid leukemia showing severe basophilia (WBC 17.1 X 10(9)/L, basophils 23%) was treated with 400mg imatinib in June 2003. A high basophil count (WBC 10.6 X 10(9)/L, basophils 31%) was still observed after 1 week of therapy. After 9 days of therapy, she developed generalized pruritic skin erythema, chills and high fever. After terminating imatinib treatment, prednisolone therapy was initiated. The rash quickly disappeared. Four days after withdrawal of imatinib, leukocyte count was 13.0 X 10(9)/L with 3% of basophils, suggesting the possibility that rapid decrease in basophils following imatinib therapy may induce severe cutaneous reactions.     

Secondary hyperparathyroidism but stable bone-mineral density in patients with chronic myeloid leukemia treated with imatinib

Imatinib is currently the standard treatment for chronic myeloid leukemia(CML). Previous studies have shown that imatinib affects bone metabolism in CML patients. However, these effects are not well-studied prospectively. The authors studied bone-mineral density (BMD) and bone metabolism in 17 CML patients and matched controls in 2007 and now repeated the analyses prospectively in 2011. All CML patients were in complete cytogenetic remission during this 4-year period and treated with 400 mg imatinib q.d. (n 5 15) or 600 mg imatinib q.d. (n 5 2). Mean treatment duration was 102 months (range 69–129) in 2011. The authors found that serum levels of parathyroid hormone increased significantly in the patients between 2007 and 2011, and seven out of 17 patients had secondary hyperparathyroidism in 2011. However, the mean areal and volumetric BMDs were stable in the CML patients over the 4-year-observation period. Moreover, the CML patients had significantly higher volumetric BMD in the cortical compartment when compared with controls in 2011 and 2007. Thus, despite a high incidence of secondary hyperparathyroidism,there were no signs of osteoporosis or osteomalacia in imatinib-treated CML patients as suggested earlier.     

Discontinuation of imatinib in Japanese patients with chronic myeloid leukemia

It was recently recognized that some chronic myeloid leukemia patients with a complete molecular response could sustain that response after discontinuation of imatinib. To characterize the clinical outcomes and profiles of chronic phase chronic myeloid leukemia patients who could discontinue imatinib, we conducted a nationwide survey in Japan. Among 3,242 imatinib-treated chronic myeloid leukemia patients, we identified 50 who had discontinued imatinib for at least six months; of these we analyzed 43. Molecular recurrence was detected in 19 patients, and a complete molecular response rate was estimated to be 47% following imatinib discontinuation. Based on multivariate regression analysis, imatinib dose intensity and prior interferon-α administration were independently predictive of molecular recurrence within 12 months. The depth of the molecular response should be a factor influencing long-term sustained complete molecular response after discontinuation of imatinib. Additionally, an immunological mechanism modified by interferon-α might control chronic myeloid leukemia stem cells.     

Nilotinib-induced hypothyroidism in a patient with chronic myeloid leukemia

Peripheral edema often occurs in patients with chronic myeloid leukemia (CML) treated with kinase inhibitors (TKIs). However, there are few reports indicating that the edema is caused by TKIs-induced hypothyroidism. We present the case of a 76-year-old man with chronic-phase CML who suffered from severe systemic edema after introduction of nilotinib. Laboratory tests revealed hypothyroidism; the patient was euthyroid prior to introduction of nilotinib. After further examination, we attributed this hypothyroidism to nilotinib. His edema regressed dramatically after thyroid hormone replacement therapy, with continued treatment with nilotinib. Laboratory examination of thyroid function also improved markedly. Although sunitinib, a multi-targeted TKI, is associated with a high incidence of hypothyroidism, TKIs targeting Bcr-Abl have rarely been reported to cause hypothyroidism. We report nilotinib-induced hypothyroidism, and suggest that hypothyroidism should be considered as a possible etiology when patients receivingTKIs suffer from edema.