Acute kidney injury in acute promyelocytic leukemia: a possible adverse effect of high dose arsenic trioxide in obese patients.

Arsenic trioxide (ATO)-based regimens are standard in acute promyelocytic leukemia (APL). ATO-related nephrotoxicity has not been reported. We reviewed APL patients treated with ATO to identify cases of acute kidney injury (AKI). Clinically significant cases were characterized. Multivariate analysis was performed to identify predictors of idiopathic, clinically significant AKI. One hundred and eight patients were included. ATO dose was 0.15 mg/kg/day using actual body weight with no dose cap. Thirty-one (28.7%) AKI cases were identified, 10 (32.3%) clinically significant. Six were idiopathic; five required dialysis. The proportion with significant, idiopathic AKI was 15.8% in patients receiving >15mg ATO versus 0% in those receiving ≤15mg (p = 0.001). On multivariate analysis, only ATO dose was a significant predictor of clinically significant AKI (odds ratio of 1.91, 95%CI, 1.19-3.07, p = 0.007). High-dose ATO may be associated with significant nephrotoxicity. We recommend that ATO dose be capped at 15 mg to minimize toxicity for this curable disease.

Improved outcomes among newly diagnosed patients with FMS-like tyrosine kinase 3 internal tandem duplication mutated acute myeloid leukemia treated with contemporary therapy: Revisiting the European LeukemiaNet adverse risk classification.

Mutations in fms-like tyrosine kinase 3 (FLT3) gene are common genomic alterations in acute myeloid leukemia (AML). FLT3 internal tandem duplication mutations (FLT3-ITD) have consistently been shown to be adversely prognostic, particularly those with high allelic ratio (AR). Current AML treatment strategies, including high dose cytarabine, purine analogs, FLT3 inhibitors (FLT3i), and with or without allogeneic stem cell transplant (SCT) have been shown to improve the outcomes in patients with FLT3 mutations. We analyzed a consecutive cohort of newly diagnosed patients with AML treated at a large academic medical center from January 2012 to January 2020. A total of 1576 patients with a new diagnosis of AML were reviewed. Among these, 1438 (91%) had molecular testing for FLT3 mutations and 21% (304/1438) had an FLT3 mutation, including 17% with an FLT3-ITD mutation. We show that FLT3-ITD high AR with NPM1 wild-type have significantly improved survival compared with other European LeukemiaNet (ELN) adverse risk disease. In multivariable cox proportional hazards model of patients receiving intensive or low-intensity induction regimens, FLT3 mutations did not have prognostic significance. The use of allogeneic SCT in CR1 for patients with FLT3 mutations appears to improve survival, particularly in those with ELN adverse risk disease. Overall, this data highlights the changing prognostic impact of FLT3 mutations in a contemporary era with appropriate use of induction therapy combined with targeted agents and allogenic SCT.

The cure of leukemia through the optimist's prism.

Progress is occurring at a dizzying rate across all leukemias. Since the authors' review of the topic in Cancer in 2018, numerous discoveries have been made that have improved the therapy and outcomes of several leukemia subsets. Hairy cell leukemia is potentially curable with a single course of cladribine followed by rituximab (10-year survival, ≥90%). Acute promyelocytic leukemia is curable at a rate of 80% to 90% with a nonchemotherapy regimen of all-trans retinoic acid and arsenic trioxide. The cure rate for core-binding factor acute myeloid leukemia (AML) is ≥75% with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin. Survival for patients with chronic myeloid leukemia is close to that for an age-matched normal population with BCR-ABL1 tyrosine kinase inhibitors (TKIs). Chronic lymphocytic leukemia, a previously incurable disease, may now be potentially curable with a finite duration of therapy with Bruton tyrosine kinase inhibitors and venetoclax. The estimated 5-year survival rate for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) exceeds 70% with intensive chemotherapy and ponatinib, a third-generation BCR-ABL1 TKI, and more recent nonchemotherapy regimens using dasatinib or ponatinib with blinatumomab are producing outstanding results. Survival in both younger and older patients with ALL has improved with the addition of antibodies targeting CD20, CD19 (blinatumomab), and CD22 (inotuzumab) to chemotherapy. Several recent drug discoveries (venetoclax, FLT3 and IDH inhibitors, and oral hypomethylating agents) are also improving outcomes for younger and older patients with AML and for those with higher risk myelodysplastic syndrome.

Acute myeloid leukemia: Treatment and research outlook for 2021 and the MD Anderson approach.

The unraveling of the pathophysiology of acute myeloid leukemia (AML) has resulted in rapid translation of the information into clinical practice. After more than 40 years of slow progress in AML research, the US Food and Drug Administration has approved nine agents for different AML treatment indications since 2017. In this review, we detail the progress that has been made in the research and treatment of AML, citing key publications related to AML research and therapy in the English literature since 2000. The notable subsets of AML include acute promyelocytic leukemia (APL), core-binding factor AML (CBF-AML), AML in younger patients fit for intensive chemotherapy, and AML in older/unfit patients (usually at the age cutoff of 60-70 years). We also consider within each subset whether the AML is primary or secondary (therapy-related, evolving from untreated or treated myelodysplastic syndrome or myeloproliferative neoplasm). In APL, therapy with all-trans retinoic acid and arsenic trioxide results in estimated 10-year survival rates of ≥80%. Treatment of CBF-AML with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin (GO) results in estimated 10-year survival rates of ≥75%. In younger/fit patients, the "3+7" regimen (3 days of daunorubicin + 7 days of cytarabine) produces less favorable results (estimated 5-year survival rates of 35%; worse in real-world experience); regimens that incorporate high-dose cytarabine, adenosine nucleoside analogs, and GO are producing better results. Adding venetoclax, FLT3, and IDH inhibitors into these regimens has resulted in encouraging preliminary data. In older/unfit patients, low-intensity therapy with hypomethylating agents (HMAs) and venetoclax is now the new standard of care. Better low-intensity regimens incorporating cladribine, low-dose cytarabine, and other targeted therapies (FLT3 and IDH inhibitors) are emerging. Maintenance therapy now has a definite role in the treatment of AML, and oral HMAs with potential treatment benefits are also available. In conclusion, AML therapy is evolving rapidly and treatment results are improving in all AML subsets as novel agents and strategies are incorporated into traditional AML chemotherapy. LAY SUMMARY: Ongoing research in acute myeloid leukemia (AML) is progressing rapidly. Since 2017, the US Food and Drug Administration has approved 10 drugs for different AML indications. This review updates the research and treatment pathways for AML.

Sorafenib plus intensive chemotherapy improves survival in patients with newly diagnosed, FLT3-internal tandem duplication mutation-positive acute myeloid leukemia.

BACKGROUND: The addition of midostaurin to induction chemotherapy improves survival in younger patients with newly diagnosed, FLT3-mutated acute myeloid leukemia (AML). Sorafenib is a potent multikinase inhibitor with efficacy when given as monotherapy. The authors investigated whether the addition of sorafenib to intensive induction chemotherapy improves outcomes in patients with FLT3-internal tandem duplication (ITD)-mutated AML. METHODS: In total, 183 patients who were newly diagnosed with FLT3-ITD-mutated AML between February 2001 and December 2017 were identified. Of these, 79 patients (43%) underwent intensive chemotherapy with the addition of sorafenib, and 104 (57%) received intensive chemotherapy alone. Propensity score matching identified 42 patients in each cohort. RESULTS: The overall response rate was 98% in the sorafenib cohort and 83% in the intensive chemotherapy cohort (P = .057). The median follow-up was 54 months. The median event-free survival was 35 months in the sorafenib cohort and 8 months in the intensive chemotherapy cohort (P = .019), and the median overall survival was 42 and 13 months, respectively (P = .026). With censoring at the time of allogeneic stem cell transplantation, the median event-free survival was 31 and 8 months in the sorafenib and intensive therapy cohorts, respectively (P = .031), and the median overall survival was not reached and 10 months, respectively (P = .001). Multivariate Cox proportional hazards models confirmed that treatment with sorafenib was a favorable prognostic factor (P = .009; hazard ratio, 0.558; 95% CI, 0.360-0.865). CONCLUSIONS: The addition of sorafenib improves survival in patients with FLT3-ITD-mutated AML regardless of whether they undergo allogeneic stem cell transplantation.

The financial burden and distress of patients with cancer: Understanding and stepping-up action on the financial toxicity of cancer treatment.

"Financial toxicity" has now become a familiar term used in the discussion of cancer drugs, and it is gaining traction in the literature given the high price of newer classes of therapies. However, as a phenomenon in the contemporary treatment and care of people with cancer, financial toxicity is not fully understood, with the discussion on mitigation mainly geared toward interventions at the health system level. Although important, health policy prescriptions take time before their intended results manifest, if they are implemented at all. They require corresponding strategies at the individual patient level. In this review, the authors discuss the nature of financial toxicity, defined as the objective financial burden and subjective financial distress of patients with cancer, as a result of treatments using innovative drugs and concomitant health services. They discuss coping with financial toxicity by patients and how maladaptive coping leads to poor health and nonhealth outcomes. They cover management strategies for oncologists, including having the difficult and urgent conversation about the cost and value of cancer treatment, availability of and access to resources, and assessment of financial toxicity as part of supportive care in the provision of comprehensive cancer care. CA Cancer J Clin 2018;68:153-165. © 2018 American Cancer Society.

Improvement in clinical outcome of FLT3 ITD mutated acute myeloid leukemia patients over the last one and a half decade.

AML with FLT3 ITD mutations are associated with poor outcome. We reviewed outcomes of patients with FLT3 ITD mutated AML to investigate trends over time. We analyzed 224 AML patients (excluding patients with core binding factor and acute promyelocytic leukemia) referred to our institution between 2000 and 2014. Patients were divided into five cohorts by era: 2000-2002 (Era 1, n = 19), 2003-2005 (Era 2, n = 41), 2006-2008 (Era 3, n = 53), 2009-2011 (Era 4, n = 55), and 2012-2014 (Era 5, n = 56) to analyze differences in outcome. The baseline characteristics were not statistically different across Eras. The response rate (CR/CRp) from Era 1-5 was 68%, 49%, 72%, 73%, and 75%, respectively. The overall response rate (all Eras) with chemotherapy alone versus chemotherapy plus FLT3 inhibitor was 67% and 72.5%, respectively (P = 0.4). The median time to relapse was 6, 3.6, 7.9, 8.1 months and not reached from Eras 1 through 5, respectively (P = 0.001). The median OS has improved: 9.6, 7.6, 14.4, 15.7, and 17.8 month from Eras 1-5, respectively (P = <0.001). Stem cell transplant as a time-dependent variable, showed better OS in the univariate analysis (HR: 0.57, 95% CI: 0.39-0.84, P = 0.004) but did not retained its significance in multivariate analysis (HR: 0.75, 95% CI: 0.50-1.13, P = 0.16). Our data suggest improvement in outcome of FLT3 ITD mutated AML patients over the last 15 years. This is probably due to improvement in treatment strategies, including but not limited to integration of FLT3 inhibitors and increased use of SCT.

Treatment with FLT3 inhibitor in patients with FLT3-mutated acute myeloid leukemia is associated with development of secondary FLT3-tyrosine kinase domain mutations.

BACKGROUND: FLT3-internal tandem duplication (ITD) mutations are found in approximately 30% of patients with acute myeloid leukemia (AML). FLT3 inhibitors have shown clinical activity in AML with FLT3-ITD, but responses are usually short-lived. METHODS: This study examined 69 FLT3-mutated patients with AML, who were treated with different FLT3 inhibitors to analyze emergence of new mutations. RESULTS: At baseline, 87% of patients had an ITD mutation, 7% had a D835/I836 mutation, and 6% had combined ITD and D835/I836 mutations. Responses occurred in 32% of patients, all with FLT3-ITD; none of the patients with D835/I836 or ITD+D835/I836 responded. Mutational assessment at the time of FLT3 inhibitor discontinuation showed that 68% of patients were unchanged, 10% had become undetectable, and 22% of patients progressed from a single ITD to have combined ITD+D835/I836 mutations. In those patients with unchanged FLT3 mutation at progression, the median survival was 5 months, whereas in those with undetectable and with combined ITD+D835/I836 mutations, the median survival was 7 months, respectively. CONCLUSIONS: These data confirm in vitro observations that a secondary tyrosine kinase domain mutation may arise after the use of FLT3 inhibitors in patients with single FLT3-ITD mutated AML, a phenomenon that is associated with resistance and a poor prognosis.

Preclinical and early clinical evaluation of the oral AKT inhibitor, MK-2206, for the treatment of acute myelogenous leukemia.

PURPOSE: Recent studies suggested that AKT activation might confer poor prognosis in acute myelogenous leukemia (AML), providing the rationale for therapeutic targeting of this signaling pathway. We, therefore, explored the preclinical and clinical anti-AML activity of an oral AKT inhibitor, MK-2206. Experimental Methods: We first studied the effects of MK-2206 in human AML cell lines and primary AML specimens in vitro. Subsequently, we conducted a phase II trial of MK-2206 (200 mg weekly) in adults requiring second salvage therapy for relapsed/refractory AML, and assessed target inhibition via reverse phase protein array (RPPA). RESULTS: In preclinical studies, MK-2206 dose-dependently inhibited growth and induced apoptosis in AML cell lines and primary AML blasts. We then treated 19 patients with MK-2206 but, among 18 evaluable participants, observed only 1 (95% confidence interval, 0%-17%) response (complete remission with incomplete platelet count recovery), leading to early study termination. The most common grade 3/4 drug-related toxicity was a pruritic rash in 6 of 18 patients. Nevertheless, despite the use of MK-2206 at maximum tolerated doses, RPPA analyses indicated only modest decreases in Ser473 AKT (median 28%; range, 12%-45%) and limited inhibition of downstream targets. CONCLUSIONS: Although preclinical activity of MK-2206 can be demonstrated, this inhibitor has insufficient clinical antileukemia activity when given alone at tolerated doses, and alternative approaches to block AKT signaling should be explored.

Long-term response to imatinib is not affected by the initial dose in patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase: final update from the Tyrosine Kinase Inhibitor Optimization and Selectivity (TOPS) study.

The TOPS trial evaluated high- (800 mg/day; n = 319) versus standard-dose (400 mg/day; n = 157) imatinib in patients newly diagnosed with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase. Patients had a minimum follow-up of 42 months or discontinued early. Major molecular response (MMR) rates were similar between arms at (51.6 vs 50.2 % for 400 and 800 mg/day, respectively; P = 0.77) and by (75.8 vs 79.0 %; P = 0.4807) 42 months. There were no differences in event-free survival (EFS), progression-free survival(PFS), or overall survival (OS) between arms. The estimated rates of PFS on treatment and OS at 42 months were significantly higher in patients with MMR at 6, 12, and 18 months compared with those without MMR.Adverse events were more frequent with high-dose imatinib. Patients with B1 treatment interruption (vs [1) and those able to maintain imatinib C600 mg/day (vs\600 mg/day) in the first year of treatment had faster and higher response rates, but no improvement in EFS or PFS. Adherence to prescribed dose without interruption may be more important than initiation of therapy with higher doses of imatinib. Achievement of MMR correlated with longterm clinical outcomes.

Current practices in the management of chronic myeloid leukemia.

BACKGROUND: A previous survey of physician self-reported practice patterns in the management of CML was conducted in 2005. The National Comprehensive Cancer Network and European LeukemiaNet guidelines now include nilotinib and dasatinib in their treatment algorithms for CML. To assess these new guidelines, a cross-sectional survey of US hematologists and/or oncologists was conducted in December 2010 through an online survey. MATERIALS AND METHODS: The survey had 43 questions consisting of items updated from the 2005 survey to reflect changes in clinical practice, tyrosine kinase inhibitor therapy, and current guidelines. RESULTS: Analysis of the responses from 507 board certified medical oncologists/hematologists suggests that the use of imatinib 400 mg as an initial treatment option had decreased from 62% in 2005 to 52% in the 2010 survey. Currently, nearly 40% of physicians would choose either nilotinib or dasatinib as first-line treatment. From the surveyed physicians, achievement of at least a major molecular response (MMR) is the predominant treatment goal in chronic phase CML. CONCLUSION: This survey emphasizes the need for continued updates and education regarding optimal therapy, monitoring practices, and therapeutic end points in CML.

Initial molecular response at 3 months may predict both response and event-free survival at 24 months in imatinib-resistant or -intolerant patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase treated with nilotinib.

PURPOSE: The association between initial molecular response and longer-term outcomes with nilotinib was examined. PATIENTS AND METHODS: Patients with imatinib-resistant or -intolerant chronic myeloid leukemia in chronic phase from the phase II nilotinib registration study with available postbaseline BCR-ABL1 transcript assessments were included (N = 237). RESULTS: BCR-ABL1 transcript levels (International Scale [IS]) at 3 months correlated with complete cytogenetic response (CCyR) by 24 months. Patients with BCR-ABL1 (IS) of > 1% to ≤ 10% at 3 months with nilotinib had higher cumulative incidence of CCyR by 24 months than patients with BCR-ABL1 (IS) of > 10% (53% v 16%). BCR-ABL1 (IS) at 3 months predicted major molecular response (MMR) by 24 months. Cumulative incidence of MMR by 24 months for patients with BCR-ABL1 (IS) of > 0.1% to ≤ 1%, > 1% to ≤ 10%, and > 10% was 65%, 27%, and 9%, respectively. These differences were observed for patients with or without baseline BCR-ABL1 mutations and for those with imatinib resistance or intolerance. Estimated event-free survival (EFS) rates at 24 months decreased with higher transcript levels at 3 months; patients with BCR-ABL1 (IS) of ≤ 1% had an estimated 24-month EFS rate of 82%, compared with 70% for patients with BCR-ABL1 (IS) of > 1% to ≤ 10% and 48% for patients with BCR-ABL1 (IS) of > 10%. CONCLUSION: Patients with BCR-ABL1 (IS) of > 10% at 3 months had a lower cumulative incidence of CCyR and MMR and lower rates of EFS versus patients with BCR-ABL1 (IS) of ≤ 10%. Prospective studies may determine whether close monitoring or alternative therapies are warranted for patients with minimal initial molecular response.

A phase I study of pemetrexed in patients with relapsed or refractory acute leukemia.

PURPOSE: To investigate the toxicity profile, activity, pharmacokinetics, and pharmacodynamics of pemetrexed in leukemia. PATIENTS AND METHODS: Patients with refractory or relapsed acute leukemia were eligible. A phase I 3+3 design was implemented. Pemetrexed was infused intravenously (IV) over 25 min with vitamin supplementation. Courses were repeated every 3 to 4 weeks according to toxicity and efficacy. The starting dose of 900 mg/m² was escalated by approximately 33% until the dose-limiting toxicity (DLT) was determined. RESULTS: Twenty patients with acute myeloid (AML) or lymphocytic (ALL) leukemia received therapy. The main non-hematologic adverse event was liver dysfunction at several dose levels, including 2 DLTs at 3,600 mg/m². One patient with ALL (3,600 mg/m² dose level) achieved a partial response. Pemetrexed pharmacokinetics were linear with escalated dosing. Elevated plasma deoxyuridine was observed in a subset of patients following pemetrexed infusion, but was not correlated with dose levels. Changes in the nucleotide pools of circulating mononuclear cells were observed, but were variable. CONCLUSIONS: The recommended phase II dose of pemetrexed for future leukemia studies is 2,700 mg/m(2) IV over 25 min every 3 to 4 weeks with vitamin supplementation. Deoxyuridine levels did not increase with increasing pemetrexed dose, suggesting pemetrexed inhibition of thymidylate synthase (TS) may be saturated by the 900 mg/m² dose level. However, no firm conclusion can be made regarding TS saturation in tumor cells. While tolerable, pemetrexed monotherapy had limited activity in this highly refractory population. Exploration of pemetrexed in combination with other active agents in leukemia is a reasonable future endeavor.

Phase I/II study of combination therapy with sorafenib, idarubicin, and cytarabine in younger patients with acute myeloid leukemia.

PURPOSE To determine the efficacy and toxicity of the combination of sorafenib, cytarabine, and idarubicin in patients with acute myeloid leukemia (AML) younger than age 65 years. PATIENTS AND METHODS In the phase I part of the study, 10 patients with relapsed AML were treated with escalating doses of sorafenib with chemotherapy to establish the feasibility of the combination. We then treated 51 patients (median age, 53 years; range, 18 to 65 years) who had previously untreated AML with cytarabine at 1.5 g/m(2) by continuous intravenous (IV) infusion daily for 4 days (3 days if > 60 years of age), idarubicin at 12 mg/m(2) IV daily for 3 days, and sorafenib at 400 mg orally twice daily for 7 days. RESULTS Overall, 38 (75%) patients have achieved a complete remission (CR), including 14 (93%) of 15 patients with mutated FMS-like tyrosine kinase-3 (FLT3; the 15th patient had complete remission with incomplete platelet recovery [CRp]) and 24 (66%) of 36 patients with FLT3 wild-type (WT) disease (three additional FLT3-WT patients had CRp). FLT3-mutated patients were more likely to achieve a CR than FLT3-WT patients (P = .033). With a median follow-up of 54 weeks (range, 8 to 87 weeks), the probability of survival at 1 year is 74%. Among the FLT3-mutated patients, 10 have relapsed and five remain in CR with a median follow-up of 62 weeks (range, 10 to 76 weeks). Plasma inhibitory assay demonstrated an on-target effect on FLT3 kinase activity. CONCLUSION Sorafenib can be safely combined with chemotherapy, produces a high CR rate in FLT3-mutated patients, and inhibits FLT3 signaling.

Phase III, randomized, open-label study of daily imatinib mesylate 400 mg versus 800 mg in patients with newly diagnosed, previously untreated chronic myeloid leukemia in chronic phase using molecular end points: tyrosine kinase inhibitor optimization and selectivity study.

PURPOSE: To evaluate the safety and efficacy of initial treatment with imatinib mesylate 800 mg/d (400 mg twice daily) versus 400 mg/d in patients with newly diagnosed chronic myeloid leukemia in chronic phase. PATIENTS AND METHODS: A total of 476 patients were randomly assigned 2:1 to imatinib 800 mg (n = 319) or 400 mg (n = 157) daily. The primary end point was the major molecular response (MMR) rate at 12 months. RESULTS: At 12 months, differences in MMR and complete cytogenetic response (CCyR) rates were not statistically significant (MMR, 46% v 40%; P = .2035; CCyR, 70% v 66%; P = .3470). However, MMR occurred faster among patients randomly assigned to imatinib 800 mg/d, who had higher rates of MMR at 3 and 6 months compared with those in the imatinib 400-mg/d arm (P = .0035 by log-rank test). CCyR also occurred faster in the 800-mg/d arm (CCyR at 6 months, 57% v 45%; P = .0146). The most common adverse events were edema, gastrointestinal problems, and rash, and all were more common in patients in the 800-mg/d arm. Grades 3 to 4 hematologic toxicity also occurred more frequently in patients receiving imatinib 800 mg/d. CONCLUSION: MMR rates at 1 year were similar with imatinib 800 mg/d and 400 mg/d, but MMR and CCyR occurred earlier in patients treated with 800 mg/d. Continued follow-up is needed to determine the clinical significance of earlier responses on high-dose imatinib.

Managing iron overload in patients with myelodysplastic syndromes with oral deferasirox therapy.

Patients with myelodysplastic syndromes (MDS) often require chronic RBC transfusions, which can lead to iron overload. Without adequate management, this may cause progressive damage to hepatic, endocrine, and cardiac organs, significantly affecting overall survival. Recent retrospective analyses have suggested that iron chelation provides a survival advantage in iron-overloaded patients with MDS who are given chelation therapy compared with those who are not. Nonetheless, it is evident that iron overload in many patients with MDS is not adequately managed. Clinical evaluation of the once-daily, oral iron chelator deferasirox in MDS populations has indicated that it provides dose-dependent reductions in body iron burden and is generally well tolerated, with a manageable safety profile in adult and pediatric patients. The most common treatment-related adverse events (AEs) included transient, mild-to-moderate gastrointestinal disturbances and skin rash, which rarely required drug discontinuation and resolved spontaneously in most cases. Adequate management of AEs and practical approaches such as patient education and counseling are necessary to ensure that patients remain compliant with therapy. Regular monitoring of serum ferritin levels is key to identifying patients who require iron chelation therapy, and to ensure maintenance of iron levels below the critical level of 1,000 microg/l. The flexible dosing regimen of deferasirox allows dose adjustments to be made in response to trends in serum ferritin, to changes in a patient's transfusional iron intake, and to the objectives of treatment, allowing the full benefit of transfusion therapy without the risks associated with iron overload.

Suboptimal response to or failure of imatinib treatment for chronic myeloid leukemia: what is the optimal strategy?

Treatment responses to imatinib vary among patients with chronic myeloid leukemia (CML), and definitions of treatment failure and suboptimal response have been published. This article discusses monitoring and treatment of patients with CML after failure of or suboptimal response to imatinib therapy. We reviewed articles listed on PubMed from January 1, 2002, to July 31, 2008, and abstracts from the 2007 Annual Meeting of the American Society of Hematology. Search terms used were chronic myeloid/myelogenous leukemia, imatinib, and BCR-ABL. To enable early recognition of suboptimal responses, patients should be frequently monitored according to published guidelines, including cytogenetic analysis every 6 months until a complete response is achieved and molecular monitoring every 3 months from the start of therapy or monthly if an increasing BCR-ABL1 transcript level is detected. Mutational analysis of BCR-ABL1 may assist with treatment selection. A recent survey suggests that a notable proportion of physicians do not follow treatment guidelines and that broader communication is required. Recent recommendations state that, in patients whose response to imatinib at 400 mg/d is suboptimal, the dose should be increased, whereas alternative therapies, such as dasatinib, nilotinib, and allogeneic stem cell transplant (in eligible patients), and imatinib dose escalation should be considered after imatinib failure. However, clinical data are lacking to confirm this sequence of treatments, and introducing alternative therapies at an earlier stage of treatment, for example, after a suboptimal response, may produce better long-term outcomes in a higher proportion of patients. Patient and disease characteristics should be carefully considered to optimize treatment strategy for CML.

Red blood cell transfusions and iron overload in the treatment of patients with myelodysplastic syndromes.

BACKGROUND: Approximately 15,000 new cases of myelodysplastic syndromes (MDS) are expected in the United States each year. METHODS: The mainstay for the management of myelodysplastic syndromes (MDS) is supportive therapy with red blood cell (RBC) transfusions to improve the patient's quality of life. RBC transfusions enable adequate tissue oxygenation and increase hemoglobin levels, improve fatigue, and improve the physical and intellectual activity of patients. Up to 90% of patients with MDS will receive RBC transfusions during the course of their disease, and many will become chronically dependent on transfusions to manage their anemia. These transfusions lead to an accumulation of excess iron that, in turn, can develop into a condition known as iron overload, causing clinical consequences like hypertransaminasemia and cirrhosis, dilated cardiomyopathy, and progressive dysfunction of the endocrine glands. RESULTS: Studies in patients with MDS have indicated that iron overload because of RBC transfusions was an independent, adverse prognostic factor for overall survival (OS) and leukemia-free survival (LFS): OS and LFS were significantly shorter in transfusion-dependent patients with MDS than in those who were not transfusion dependent. CONCLUSIONS: Although the National Comprehensive Cancer Network guidelines for the treatment of patients with MDS recommend the use of RBC transfusions as supportive care, they further recommend that the iron burden of transfused patients be monitored regularly and that iron chelation therapy be considered to maintain serum ferritin levels of <1000 ng/mL.

N-(4-Hydroxylphenyl)retinamide (fenretinide, 4-HPR), a retinoid compound with antileukemic and proapoptotic activity in acute lymphoblastic leukemia (ALL).

BACKGROUND: Retinoids have been shown to regulate vital cellular processes including cell proliferation, differentiation and apoptosis. N-(4-Hydroxyphenyl)-all-trans-retinamide (fenretinide, 4-HPR) is a synthetic ATRA derivative with chemopreventive and cytotoxic activity against various cancer cell lines including myeloid leukemia. Although several modes of action have been postulated, its mechanism of action in hematologic malignancies remains unclear. Furthermore, only limited information exists as to its activity in lymphoid malignancies. METHODS AND RESULTS: To test whether 4-HPR has activity in acute lymphoblastic leukemia (ALL), we first analyzed its antiproliferative effect in five ALL (Z-33, Z-138, Z-119, Z-181, and Jurkat) cell lines. We found that 4-HPR inhibited the proliferation of all cell lines in a dose-dependent manner at concentrations ranging from 1 to 10 microM. We further demonstrated by cell cycle analysis that 5 microM of 4-HPR blocked Z-119 cells in S phase thus preventing their progression through the cycle. Next we tested whether 4-HPR activated the caspase pathway and induced apoptotic cell death. We found that 4-HPR induced apoptosis in Z-119 cells through the activation of caspase-3 and subsequent cleavage of its substrate poly(ADP-ribose) polymerase (PARP). We then asked whether 4-HPR could affect fresh ALL progenitor cells. Therefore, we obtained bone marrow and peripheral blood cells from five patients with newly diagnosed ALL and tested the effect of 4-HPR using the ALL blast colony culture assay. To supplement our results, we also performed the ALL blast assay on one ALL cell line (ALL-1). We found that 4-HPR significantly inhibited ALL colony-forming cell proliferation in a dose-dependent manner. CONCLUSIONS: Our data show that 4-HPR is a potent inhibitor of ALL cell proliferation and that it induces in vitro apoptotic cell death in ALL blasts. Further studies are warranted to establish the in vivo effect of 4-HPR particularly in patients with ALL.