Identification of genomic biomarkers for anthracycline-induced cardiotoxicity in human iPSC-derived cardiomyocytes: an in vitro repeated exposure toxicity approach for safety assessment

The currently available techniques for the safety evaluation of candidate drugs are usually cost-intensive and time-consuming and are often insufficient to predict human relevant cardiotoxicity. The purpose of this study was to develop an in vitro repeated exposure toxicity methodology allowing the identification of predictive genomics biomarkers of functional relevance for drug-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The hiPSC-CMs were incubated with 156 nM doxorubicin, which is a well-characterized cardiotoxicant, for 2 or 6 days followed by washout of the test compound and further incubation in compound-free culture medium until day 14 after the onset of exposure. An xCELLigence Real-Time Cell Analyser was used to monitor doxorubicin-induced cytotoxicity while also monitoring functional alterations of cardiomyocytes by counting of the beating frequency of cardiomyocytes. Unlike single exposure, repeated doxorubicin exposure resulted in long-term arrhythmic beating in hiPSC-CMs accompanied by significant cytotoxicity. Global gene expression changes were studied using microarrays and bioinformatics tools. Analysis of the transcriptomic data revealed early expression signatures of genes involved in formation of sarcomeric structures, regulation of ion homeostasis and induction of apoptosis. Eighty-four significantly deregulated genes related to cardiac functions, stress and apoptosis were validated using real-time PCR. The expression of the 84 genes was further studied by real-time PCR in hiPSC-CMs incubated with daunorubicin and mitoxantrone, further anthracycline family members that are also known to induce cardiotoxicity. A panel of 35 genes was deregulated by all three anthracycline family members and can therefore be expected to predict the cardiotoxicity of compounds acting by similar mechanisms as doxorubicin, daunorubicin or mitoxantrone. The identified gene panel can be applied in the safety assessment of novel drug candidates as well as available therapeutics to identify compounds that may cause cardiotoxicity.

Model systems for cardiotoxic effects of anthracyclines

The use of anthracycline antibiotics in cancer chemotherapy is limited by their cardiotoxic qualities. For the evaluation of new derivatives animal model systems are required. Cardiomyopathy can be induced in rabbits and monkeys, but these models are too expensive for screening purposes. In rats, anthracycline antibiotics cause morphologic lesions of the heart muscle, but these are more difficult to demonstrate than in larger animals. However, significant changes of the heart function (electrocardiogram (ECG), cardiac output), the function of heart mitochondria (inhibition of electron transfer, uncoupling of oxidative phosphorylation and inhibition of Ca translocation) occur in a dose-related manner. Intraventricular conduction defect demonstrated in the ECG is one of the earliest and most consistent expressions of the cardiotoxic properties of anthracyclines. It was therefore used as primary screening parameter. The results of the screening of over 50 new anthracyclines has shown that the cardiotoxic properties vary considerably and that they are not closely related to the chemotherapeutic and the hematotoxic properties. Interesting structure-activity relationships were observed in a series of rubidazone derivatives substituted at the benzhydrazone part of the molecule.

Phase 2 trial of CPX-351, a fixed 5:1 molar ratio of cytarabine/daunorubicin, vs cytarabine/daunorubicin in older adults with untreated AML

CPX-351 is a liposomal formulation of cytarabine:daunorubicin designed to deliver synergistic drug ratios to leukemia cells. In this phase 2 study, newly diagnosed older acute myeloid leukemia (AML) patients were randomized 2:1 to first-line CPX-351 or 7+3 treatment. The goal was to determine efficacy and identify patient subgroups that may benefit from CPX-351 treatment. Response rate (complete remission + incomplete remission) was the primary end point, with event-free survival (EFS) and overall survival (OS) as secondary end points. The 126 patients entered were balanced for disease and patient-specific risk factors. Overall, CPX-351 produced higher response rates (66.7% vs 51.2%, P = .07), meeting predefined criteria for success (P < .1). Differences in EFS and OS were not statistically significant. A planned analysis of the secondary AML subgroup demonstrated an improved response rate (57.6% vs 31.6%, P = .06), and prolongation of EFS (hazard ratio [HR] = 0.59, P = .08) and OS (HR = 0.46, P = .01). Recovery from cytopenias was slower after CPX-351 (median days to absolute neutrophil count ≥1000: 36 vs 32; platelets >100 000: 37 vs 28) with more grade 3-4 infections but without increase in infection-related deaths (3.5% vs 7.3%) or 60-day mortality (4.7% vs 14.6%), indicating acceptable safety. These results suggest a clinical benefit with CPX-351, particularly among patients with secondary AML, and provide the rationale for a phase 3 trial currently underway in newly diagnosed secondary AML patients. This study is registered at Clinicaltrials.gov as #NCT00788892.

[Treating patients with acute myeloid leukemias (AML) according to the protocol of the AML-01.10 Russian multicenter randomized trial: the coordinating center's results]

AIM

To make a randomized comparison of 2 consolidation treatment options (two patient groups): 2 cycles of cytarabine in average (Ig/m2 in Group 2) and standard (100 mg/mi2 in Group 1) doses in combination with idarubicin (8-12 mg/m2) and mitoxantrone (10 mg/m2), after two 7+3 induction cycles of daunorubicin (60 mg/mi2) and subsequent 6 cycles of maintenance therapy.

SUBJECTS AND METHODS

In January 2010 to October 2013, a Russian multicenter trial was conducted to treat patients with acute myeloid leukemias (AML) in accordance with the AML-01.10 protocol (ClinicalTrials.gov Identifier: NCT01587430). The trial enrolled 243 AML patients from 21 centers, including 71 patients (median age 38 years) from the State Hematology Center, Ministry of Health of the Russian Federation; 35 and 36 patients were randomized to Groups 1 and 2, respectively. The randomized groups were balanced by basic clinical and laboratory parameters. Favorable, intermediate, and high cytogenetic prognoses were in 14 (21.9%), 40 (62.5%), and 10 (15.6%) patients, respectively.

RESULTS

Prior to treatment, 2 patients died; one patient refused treatment. Fifty-eight (85.3%) of the 68 patients achieved complete remission (CR); early deaths was in 2 (2.9%) and resistance in 8 (11.8%). Four (6.9%) patients died during CR. Protocol deviations (doses, intervals, and the number of cycles) were recorded in 12 (20.7%) of the 58 patients. Other 8 (11.8%) patients were switched to low-dose cytarabine because of complications, withdrawn from the protocol and not included into the analysis of randomized comparison. Twenty allogeneic bone marrow transplantations (allo-BMT) (7 related, 12 unrelated, and 1 haploidentical) were performed; of them 15 allo-BMTs were done during first CR. In the 68 patients, 3-year overall survival (OS) was 45.6%; relapse-free survival (RFS) was 41.5%. OS was 64.6% in Group 1 and 58.3% in Group 2; RFS was 62 and 38.8% in Groups 1 and 2, respectively (p>0.5). In the favorable, intermediate, and high prognosis groups, OS was 79.5, 60, and 31.1% and RFS was 81.8, 41.3, and 33.3%, respectively (p=0.1). The consolidation treatment option unchanged survival rates in the above risk groups. Unachieved CR after the first cycle considerably decreased RFS (33.9% versus 60%) and served as an indication for allo-BMT during first CP (RFS without BMT was 0; that with BMT was 78%).

CONCLUSION

No differences were found between both consolidation options according to long-term results. Protocol deviations were recorded in one-third of the patients. While implementing the protocol, the efficiency of treatment was high. Allo-BMT during first CR substantially increased RFS if CP was not achieved after the first cycle.

Immunomodulatory effects of Hedysarum polybotrys extract in mice macrophages, splenocytes and leucopenia

Astragali Radix (Huang-Qi) is a popular herbal medicine commonly used as a constituent in tonic herbal preparations. Hedysarum polybotrys Handel-Mazzetti is one species used of Astragali Radix. In this study, the immunomodulatory properties of H. polybotrys were explored by LPS-activated and SNP-treated RAW 264.7 cells and splenocytes and, daunoblastina-induced leucopenia BALB/c mice. Formononetin was used as the bioactive marker to monitor the quality of the H. polybotrys extracts. H. polybotrys was extracted with hot-water and methanol, and MeOH extract partitioned with H₂O (M-H) and ethyl acetate (M-EA) to yield four different fractions. M-EA had the highest formononetin and total proanthocyanidin content and showed stronger inhibitory effects on the production and expression of NO, PGE₂, iNOS and COX-2 in LPS-activated RAW 264.7 cells and splenocytes than the other fractions. In addition, M-EA significantly stimulated the proliferation of LPS-activated RAW 264.7 cells and splenocytes, enhanced NO radicals scavenging and attenuated NO-induced cytotoxicity. Furthermore, M-EA also significantly increased the rate of recovery of white blood cells level in daunoblastina-induced leucopenia mice. These evidences suggest that this traditional Qi-tonifying herb has potential effects in clinical conditions when immune-enhancing and anti-inflammatory effect is desired.

Administration of chromium(III) and manganese(II) as a potential protective approach against daunorubicin-induced cardiotoxicity: in vitro and in vivo experimental evidence

Daunorubicin (DNR) is a widely used antitumor drug, but its application is limited because of its cardiotoxic side effects. The present study was designed to investigate the interaction between DNR and cardiac myosin (CM) in the presence of chromium(III) (Cr(3+)) and manganese(II) (Mn(2+)) using fluorescence spectrometry under simulative physiological conditions with the aim of exploring the influence of metal ion on DNR-CM complex and finding out an aggressive approach to abrogate of DNR-induced cardiotoxicity. In detail, the quenching and binding constant of ternary system, including metal ion, DNR, and CM, were measured and compared with the DNR-CM. The data from in vitro experiments indicate that the presence of Cr(3+) or Mn(2+) distinctly decreased the binding force between DNR and CM, and alleviated the cardiac toxicity caused by DNR. In addition, the variations in mice body weight and myocardial enzyme level were examined by in vivo experiments. Animals receiving Cr(3+) or Mn(2+) supplementation of DNR showed preservation of the normal pattern of the heart, especially 2.0 mg Cr(3+)/kg body wt or 50.0 mg Mn(2+)/kg body wt exhibited an obviously protective effect accompanied with body weight raise when compared with the mice treated with DNR alone, decreased the ratio of heart to body weight (BW) and the ratio of left ventricular mass to BW to the normal levels, and inhibited the leak of myocardial enzyme caused by DNR. As a result, this study suggests that pretreatment of lower dose of Cr(3+) (2 mg/kg wt) and moderate dose of Mn(2+) (50 mg/kg wt) might be useful and play an important role in ameliorating the cardiotoxicity of DNR treatment in cancer patients.

Cardiac Troponin T Following Anthracycline Chemotherapy in Children and Adolescents

Cardiac troponin T (CTT) is elevated acutely in animal models of anthracycline cardiotoxicity. We assessed CTT release in children receiving anthracylines using a third generation assay. We measured CTT in 30 children receiving anthracycline chemotherapy. A total of 3 samples were taken from each child: 1) prior to, 2) immediately after and 3) between 24-48 hours after the infusion. The dose range given during the measurements of cardiac troponin T was 15-60 (median 25) mg/m(2) and the previous exposure ranged from 0-300 (median 150) mg/m(2). Not one child had a detectable CTT level at any time. This study shows a lack of acute elevation CTT following anthracycline administration. In this respect it is unlikely that early estimation of CTT using this modern assay will be useful for screening for anthracycline cadiomyopathy. Further studies using a third generation assay, are, however, indicated to determine whether delayed elevation of CTT occurs.

[Organ toxicity and efficacy of high-dose daunorubicin-based chemotherapy in the treatment of acute leukemia]

OBJECTIVE

To evaluate the safety and therapeutic effect of high-dose daunorubicin-based (HD-DNR) chemotherapy in the treatment of acute leukemia (AL).

METHODS

The clinical data of 25 AL patients, including 14 cases for induction chemotherapy, 8 for consolidation chemotherapy and 3 for reinduction therapy, which were treated with HD- DNR (DNR dosage of 90 mg/m(2)× 3 d) between June 2010 and August 2012 in our hospital were retrospectively analyzed, the adverse reaction of chemotherapy, especially cardiac toxicity and therapeutic effect were evaluated.

RESULTS

Most of the adverse reactions were mild, including cardiac toxicity, and no patient discontinued therapy because of HD-DNR related toxicities. Grade 3 or higher adverse reactions occurred only in the infection (56%) and diarrhea (12%). Withdrawal or dose reduction due to strong adverse reactions was not observed in all patients. Adverse reactions of infections (92%), lower ejection fraction(52.6%), diarrhea (48%), nausea (36%), vomiting (36%), dental ulcer (36%) and myocardial ischemia (32%) were relatively more common. The median time of neutrophil count reached to ≥ 0.5 × 10(9)/L and platelet ≥ 20 × 10(9)/L were both 21 days(ranged 9-31 and 9-38 days). Nine patients were complicated with infections before chemotherapy and 14 after chemotherapy, mainly occurred in gastrointestinal tract and respiratory system. Gastrointestinal, liver and kidney toxicity was slight. The cardiac ejection decreased in 10 cases, but only 1 reached grade 2 without clinical symptoms. Of the 14 AL patients for induction chemotherapy, 13 achieved hematological complete remission. Eight patients received HD-DNR as consolidation chemotherapy remained complete remission, while 3 refractory/relapsed patients remained non-remission.

CONCLUSION

The adverse reaction of HD-DNR based chemotherapy for AL treatment was mild, no obvious cardiac adverse reaction occurred. The treatment dose of DNR at 90 mg/m(2) × 3 d can be safely and effectively used to treat acute leukemia.

Single-nucleotide polymorphisms in aldo-keto and carbonyl reductase genes are not associated with acute cardiotoxicity after daunorubicin chemotherapy

BACKGROUND

Evidence suggests that interpatient variability in anthracycline metabolic rate may contribute to the cardiotoxicity associated with anthracycline-based chemotherapy. Therefore, polymorphisms in the anthracycline metabolizing enzymes have been proposed as potential biomarkers of anthracycline-induced cardiotoxicity (AIC).

METHODS

We have previously shown that 13 of the naturally occurring nonsynonymous single-nucleotide polymorphisms (nsSNP) in the aldo-keto reductases (AKR) and carbonyl reductases (CBR) reduce anthracycline metabolic rate in vitro. Here, we test these SNPs individually and jointly for association with daunorubicin-induced cardiotoxicity in patients with acute myeloid leukemia (AML).

RESULTS

Five of the 13 nsSNPs exhibiting an in vitro effect on anthracycline metabolism were detected among the 185 patients with AML. No association was found between the SNPs and daunorubicin-induced cardiotoxicity in either individual or joint effect analyses.

CONCLUSIONS

Despite the shown in vitro effect of nsSNPs in reductase genes on anthracycline metabolic rate, on their own these SNPs do not explain enough variability in cardiotoxicity to be useful markers of this adverse event.

IMPACT

The results of this study provide important information for biomarker studies on side effects of anthracycline chemotherapy.

Prospective study of hemostatic alterations in children with acute lymphoblastic leukemia

In a group of newly diagnosed acute lymphocytic leukemia (ALL) children we evaluated a number of hemostatic and inflammatory markers at diagnosis and at different time points during chemotherapy for the remission induction to identify alterations in the plasma levels of prothrombotic markers before and during the course of chemotherapy. The following plasma markers were evaluated: thrombin-antithrombin complex (TAT), D-Dimer, plasminogen activator inhibitor 1 (PAI-1), antithrombin, fibrinogen, von Willebrand factor (VWF) antigen and high molecular weight VWF (HMW-VWF) multimers, P-selectin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6). Plasma samples were collected at the following time points: at T0 (baseline) and T1 (+24 days of therapy), T2 (+36 days therapy), and T3 (+64 days therapy). The results show that, at diagnosis, ALL children presented with laboratory signs of increased thrombin generation and fibrin formation (i.e. high TAT and D-dimer levels), fibrinolysis inhibition (i.e. high PAI-1 level), endothelial activation (i.e., high HMW-VWF and soluble P-selectin levels) and inflammation (i.e. high TNF-alpha and IL-6 levels). After starting induction therapy, the thrombin generation markers and inflammatory cytokines significantly decreased. To the opposite, PAI-1 and P-selectin significantly increased, suggesting an insult by chemotherapy on the vascular endothelium. These effects were more evident during steroid administration. Symptomatic venous thromboembolism (VTE) episodes developed in two cases during induction therapy, which did not allow the evaluation of the predictive value for VTE of laboratory markers.

Heart transplant in a childhood leukemia survivor: a case report

OBJECTIVES

Children with acute leukemia often receive therapy that is potentially cardiotoxic. Development of irreversible cardiac impairment requiring heart transplant may appear many years after anticancer therapy. Other possible causes are discussed.

MATERIAL AND METHODS

We describe a young leukemia survivor who developed severe heart failure needing a heart transplant.

RESULTS

A 4-year-old boy was treated with standard doses of chemotherapy containing cardiotoxic daunorubicin and mitoxantrone, and later, with an allogeneic bone marrow transplant. Twelve years after the diagnosis of acute myeloid leukemia, and following a viral infection of an unknown cause, he developed symptoms of heart failure. Severe dilated cardiomyopathy; and severe, left ventricular dysfunction with ejection fraction of 12% were noted on echocardiography. The patient required a heart transplant 19 years after the diagnosis of leukemia.

CONCLUSIONS

Cardiac failure may progressively occur in childhood leukemia survivors. Heart transplant is indicated in patients with refractory hemodynamic decompensation.

Sequential phase II Southwest Oncology Group studies (S0112 and S0301) of daunorubicin and cytarabine by continuous infusion, without and with ciclosporin, in older patients with previously untreated acute myeloid leukaemia

Attempts to overcome multi-drug resistance in acute myeloid leukaemia (AML) have been limited by toxicities. To investigate the effect of reducing peak drug levels, we performed sequential phase II studies using continuous infusion daunorubicin and cytarabine without (AD) and then with ciclosporin (ADC) in older patients with AML. Untreated patients (age 56+ years) received daunorubicin (45 mg/m2 per day for 3 d) and cytarabine (200 mg/m2 per day for 7 d), both by continuous infusion, without (S0112, 60 patients) and then with (S0301, 50 patients) the addition of ciclosporin. Complete response (CR) rates were 38% on S0112 and 44% on S0301. Fatal induction toxicities occurred in 17% and 12% respectively, arising primarily from infection and haemorrhage. Median overall and relapse-free survival was 7 and 8 months for AD respectively, and 6 and 14 months for ADC. Patients with phenotypic or functional P-glycoprotein had somewhat higher CR rates with ADC than AD, although confidence intervals overlapped. In these sequential trials, continuous infusion AD produced CR rates comparable to those with bolus daunorubicin. The addition of ciclosporin did not cause undue toxicities, produced a similar CR rate, and possibly improved relapse-free survival. Further correlate analyses did not identify a subpopulation specifically benefitting from the addition of ciclosporin.

Weight patterns in children with higher risk ALL: A report from the Children's Oncology Group (COG) for CCG 1961

BACKGROUND

This retrospective analysis defined and described patterns and predictors of weight change during treatment in children with acute lymphocytic leukemia (ALL) with high-risk features who received treatment on Children's Cancer Group protocol CCG 1961.

PROCEDURE

Patients (1,638) were enrolled in CCG 1961 from November 1996 to May 2002. Weight was measured as BMI percent (%), specific for age and gender, and defined as 100 x ln(BMI/median BMI).

RESULTS

By the end of treatment, 23% of children were obese (BMI >or=95%), compared with 14% at diagnosis. Children who received post-induction intensified therapy (arms C, D, SER with Doxorubicin or Idarubicin) had higher gastrointestinal toxicities and lower BMI% from consolidation through interim maintenance 1. BMI% then increased for all arms between delayed intensification and maintenance 1 or 2. Children who were of Black or Hispanic race, obese at diagnosis, or who had grade 3 or 4 pancreatitis/glucose toxicities during induction had higher BMI% throughout treatment. Children were more likely to be obese at the end of the study if they were aged 5-9 years at diagnosis or female gender. Cranial radiation was not a predictor of obesity.

CONCLUSIONS

Successful treatment of higher risk childhood ALL was associated with obesity, independent of cranial irradiation. The beginning of maintenance therapy may be the best time to intervene with nutritional and behavioral interventions, particularly for children who are obese or aged 5-9 years at diagnosis, female, Black or Hispanic, or those with metabolic toxicities during induction.

Anthracycline dose intensification in acute myeloid leukemia

BACKGROUND

In young adults with acute myeloid leukemia (AML), intensification of the anthracycline dose during induction therapy has improved the rate of complete remission but not of overall survival. We evaluated the use of cytarabine plus either standard-dose or high-dose daunorubicin as induction therapy, followed by intensive consolidation therapy, in inducing complete remission to improve overall survival.

METHODS

In this phase 3 randomized trial, we assigned 657 patients between the ages of 17 and 60 years who had untreated AML to receive three once-daily doses of daunorubicin at either the standard dose (45 mg per square meter of body-surface area) or a high dose (90 mg per square meter), combined with seven daily doses of cytarabine (100 mg per square meter) by continuous intravenous infusion. Patients who had a complete remission were offered either allogeneic hematopoietic stem-cell transplantation or high-dose cytarabine, with or without a single dose of the monoclonal antibody gemtuzumab ozogamicin, followed by autologous stem-cell transplantation. The primary end point was overall survival.

RESULTS

In the intention-to-treat analysis, high-dose daunorubicin, as compared with a standard dose of the drug, resulted in a higher rate of complete remission (70.6% vs. 57.3%, P<0.001) and improved overall survival (median, 23.7 vs. 15.7 months; P=0.003). The rates of serious adverse events were similar in the two groups. Median follow-up was 25.2 months.

CONCLUSIONS

In young adults with AML, intensifying induction therapy with a high daily dose of daunorubicin improved the rate of complete remission and the duration of overall survival, as compared with the standard dose. (ClinicalTrials.gov number, NCT00049517.)

High-dose daunorubicin in older patients with acute myeloid leukemia

BACKGROUND

A complete remission is essential for prolonging survival in patients with acute myeloid leukemia (AML). Daunorubicin is a cornerstone of the induction regimen, but the optimal dose is unknown. In older patients, it is usual to give daunorubicin at a dose of 45 to 50 mg per square meter of body-surface area.

METHODS

Patients in whom AML or high-risk refractory anemia had been newly diagnosed and who were 60 to 83 years of age (median, 67) were randomly assigned to receive cytarabine, at a dose of 200 mg per square meter by continuous infusion for 7 days, plus daunorubicin for 3 days, either at the conventional dose of 45 mg per square meter (411 patients) or at an escalated dose of 90 mg per square meter (402 patients); this treatment was followed by a second cycle of cytarabine at a dose of 1000 mg per square meter every 12 hours [DOSAGE ERROR CORRECTED] for 6 days. The primary end point was event-free survival.

RESULTS

The complete remission rates were 64% in the group that received the escalated dose of daunorubicin and 54% in the group that received the conventional dose (P=0.002); the rates of remission after the first cycle of induction treatment were 52% and 35%, respectively (P<0.001). There was no significant difference between the two groups in the incidence of hematologic toxic effects, 30-day mortality (11% and 12% in the two groups, respectively), or the incidence of moderate, severe, or life-threatening adverse events (P=0.08). Survival end points in the two groups did not differ significantly overall, but patients in the escalated-treatment group who were 60 to 65 years of age, as compared with the patients in the same age group who received the conventional dose, had higher rates of complete remission (73% vs. 51%), event-free survival (29% vs. 14%), and overall survival (38% vs. 23%).

CONCLUSIONS

In patients with AML who are older than 60 years of age, escalation of the dose of daunorubicin to twice the conventional dose, with the entire dose administered in the first induction cycle, effects a more rapid response and a higher response rate than does the conventional dose, without additional toxic effects. (Current Controlled Trials number, ISRCTN77039377; and Netherlands National Trial Register number, NTR212.)