Evaluation of cardiac toxicity of idarubicin (4-demethoxydaunorubicin)

Pharmacokinetic Comparison of 120-Hour InfusionVersusHyperfractionated Oral Administration of Idarubicin

The aim of this study was to compare the pharmacokinetics of idarubicin (IDA) and its active metabolite idarubicinol (IDOL) after chronic oral and continuous intravenous (i.v.) IDA administration in order to establish the oral doses needed to reach the i.v. equiactive plasma drug exposure. The pharmacokinetic profile of IDA and IDOL was investigated in 23 patients receiving 12 mg/m2 IDA by 120-h i.v. infusion (2.4 mg/m2/day) combined with cyclophosphamide, etoposide and prednisone in comparison to 28 patients receiving oral IDA doses ranging from 2 to 10 mg/day for 21 days in a phase I study. We found that IDA AUC24h/dose/m2 was 4.7-fold greater during i.v. than oral administration, whereas IDOL AUC24h/dose/m2 was only about 2-fold higher after i.v. administration. The metabolic ratio between IDOL AUC24h and IDA AUC24h in plasma was about 3-fold higher after oral administration. Based on these results we were able to estimate that equiactive plasma drug exposure was reached with an approximately 2.5-fold greater oral dose/m2 of IDA than the corresponding i.v. dose.

Cardiovascular complications of breast cancer therapy in older adults

Older adults frequently have pre-existing and cancer-related risk factors for cardiovascular toxicity from cancer treatment. In this review, we discuss the risk factors and strategies for prevention and management of cardiovascular complications in older women with breast cancer.

Comparison of CHOP versus CIOP in good prognosis younger patients with histologically aggressive non-Hodgkin lymphoma

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) has been the standard chemotherapy regimen used for diffuse large cell lymphomas for over 30 years. Idarubicin is a 4-demethoxy-anthracycline analogue of daunorubicin that has proven activity in non-Hodgkin lymphoma, and has been reported to cause less cardiotoxicity. We therefore initiated a randomised trial of standard dose CHOP versus CIOP (cyclophosphamide, idarubicin, vincristine and prednisolone), in which doxorubicin 50 mg/m2 was substituted by idarubicin 10 mg/m2, a dose thought to have equivalent anti-lymphoma activity. This trial was closed prematurely after 211 patients had completed therapy when a lower complete remission (CR) rate was noted in the CIOP arm. The formal results with long-term follow up are now reported. Overall response rate was 84% in the CHOP arm and 78% in the CIOP arm, CR rates were 70% and 52% respectively in all patients (P=0.013) and 73% and 52% respectively for the eligible patients (P=0.0084). At a median of 8 years follow-up, 4-year progression-free survival for all patients was 56% in the CHOP arm and 40% in the CIOP arm (P=0.0096). Overall survival for all patients was 65% in the CHOP arm and 56% in the CIOP arm (P=0.14). Results for eligible patients were comparable. CIOP containing idarubicin at a dose of 10 mg/m2 is clearly inferior to standard CHOP.

Increased myelotoxicity of idarubicin: is there a pharmacological basis? Results of a pharmacokinetic and an in vitro cytotoxicity study

BACKGROUND

Clinical trials evaluating idarubicin (IDA) in acute myeloid leukemia, multiple myeloma and non-Hodgkin's lymphoma (NHL) have provided some evidence for an increased myelotoxicity of IDA compared to other anthracyclines. IDA is known to be less sensitive towards multidrug resistance mediated by P-glycoprotein (P-gp). This phenotype is a major impediment to successful antineoplastic treatment, but P-gp is also expressed on hematopoietic stem cells (HSC).

METHODS

We investigated the pharmacokinetics of IDA and etoposide (ETO) in seven previously untreated patients with aggressive NHL. The patients received a CHOP-derived protocol (CIVEP) in which doxorubicin (DOX) was substituted by IDA 11-16 mg/m(2) and ETO 3 x 100 mg/m(2) was added. Furthermore, we evaluated in vitro the impact of P-gp expression on the cytotoxicity of DOX and IDA in cells from three parental chemosensitive leukemia and lymphoma cell lines (HL60, U937, CCRF) and their resistant sublines, as well as in CD34-positive HSC.

RESULTS

The peak plasma levels (C(max)), terminal elimination half-life (t(1/2)) and area under the concentration curve (AUC) both for IDA and for ETO did not differ from published data. In cell line models the numbers of viable cells in a P-gp-expressing resistant CCRF-VCR100 subline were significantly more reduced by IDA ( P<0.001), but there was no difference in the cytotoxicities of IDA and DOX in chemosensitive CCRF cells and in the (non-P-gp-expressing) resistant U937 and HL60 sublines. Cytotoxicity against HSC was more pronounced after incubation with IDA than after treatment with DOX ( P=0.014), even when a tenfold higher concentration of DOX than of IDA was used. The addition of cyclosporin A increased the cytotoxic effect of DOX but not that of IDA in HSC.

CONCLUSIONS

The pharmacokinetics of IDA and its main metabolite idarubicinol in CHOP-derived protocols were not different from data obtained with other combinations or monotherapy. The increased myelotoxicity of IDA may be a consequence of P-gp expression in CD34-positive HSC.

High-dose consolidation chemotherapy with Idarubicin and alkylating agents following induction with gemcitabine-epirubicin-paclitaxel in metastatic breast cancer: a dose finding study

Preliminary randomized studies have failed to show a survival benefit of high-dose chemotherapy with alkylators in advanced breast cancer. Idarubicin is an active agent in breast cancer and is suitable for dose escalation. We designed a dose finding study with escalating high-dose idarubicin (HD-Ida) followed by fixed high-dose thiotepa+melphalan (HD-TM) with peripheral blood progenitor cells (PBPC) in MBC patients with stable disease or in partial response after six courses of induction chemotherapy with gemcitabine 1000 mg/m(2) days 1 and 4, epirubicin 90 mg/m(2) day 1, taxol 175 mg/m(2) day 1 (GET). Aims of the study were to identify the maximum tolerated dose (MTD) of idarubicin, to evaluate the cardiac safety and activity of HD-Ida and HD-TM after GET and to study the pharmacokinetic profile of idarubicin and idarubicinol. A total of 14 patients were treated. Idarubicin was administered as a 48 h continuous i.v. infusion at the following dose levels: 40 mg/m(2) (three patients), 50 mg/m(2) (three patients), 60 mg/m(2) (five patients) and 70 mg/m(2) (three patients). Mucositis was the dose-limiting toxicity and the MTD was 60 mg/m(2). C(max) of Idarubicin and idarubicinol were 7.7+/-2.0 and 26.3+/-9.7 ng/ml at 40 mg/m(2) and increased to 14.8+3.0 and 47.4+12.6 ng/ml at 70 mg/m(2). AUCt(0-264) of idarubicin and idarubicinol increased from 423.2+/-111.6 and 2581+/-606 hng/ml at 40 mg/m(2) to 732.8+/-140.2 and 4590+/-1258 hng/ml at 70 mg/m(2). Conversion rates after HD-Ida and HD-TM were 28.6 and 38.5%, respectively. No episodes of cardiac toxicity were observed. We conclude that HD-Ida followed by HD-TM is feasible and devoid of cardiac toxicity. Moreover, the activity of HD-Ida after a epirubicin-containing regimen suggests incomplete cross-resistance between the two drugs.

Protective role of antioxidant vitamin E and catechin on idarubicin-induced cardiotoxicity in rats

Idarubicin is an anthracycline antibiotic extensively used in acute leukemia. In the present study we investigated whether vitamin E and catechin can reduce the toxic effects of idarubicin. Vitamin E (200 IU kg(-1) week(-1)), catechin (200 mg kg(-1) week(-1)), idarubicin (5 mg kg(-1) week(-1)), idarubicin + vitamin E (200 IU kg(-1) week(-1)), and idarubicin + catechin (200 mg kg(-1) week(-1)) combinations were given to male Sprague-Dawley rats weighing 210 to 230 g (N = 6/group). Idarubicin-treated animals exhibited a decrease in body and heart weight, a decrease in myocardial contractility, and changes in ECG parameters (P<0.01). Catechin + idarubicin- and vitamin E + idarubicin-treated groups exhibited similar alterations, but changes were attenuated in comparison to those in cardiac muscle of idarubicin-treated rats (P<0.05). Superoxide dismutase and catalase activity was reduced in the idarubicin-treated group (P<0.05). Glutathione peroxidase levels were decreased in the idarubicin-treated group (P<0.05) and reached maximum concentrations in the catechin- and catechin + idarubicin-treated groups compared to control (P<0.01). Malondialdehyde activity was decreased in the catechin + idarubicin-treated groups compared to control and increased in the other groups, reaching maximum concentrations in the vitamin E-treated group (P<0.01). In electron microscopy studies, swelling of the mitochondria and dilatation of the sarcoplasmic reticulum of myocytes were observed in the idarubicin-treated groups. In groups that were given idarubicin + vitamin E and idarubicin + catechin, the only morphological change was a weak dilatation of the sarcoplasmic reticulum. We conclude that catechin and vitamin E significantly reduce idarubicin-induced cardiotoxicity in rats.

Chemotherapy-induced cardiotoxicity: current practice and prospects of prophylaxis

Cardiotoxicity is a potential side effect of few chemotherapeutic agents. The anthracycline class of cytotoxic antibiotics are the most famous, but other chemotherapeutic agents can also cause serious cardiotoxicity and are not so well recognised. Examples include cyclophosphamide, ifosfamide, mitomycin and fluorouracil. Prediction and hence prophylaxis has always been a difficult task. Ideal monitoring techniques, upon which efficient prophylaxis depends, are yet to be determined. Current prophylaxis relies upon early detection of systolic and/or diastolic dysfunction. While somewhat useful, in some cases by the time defects are detected progression of chemotherapy-induced cardiomyopathy is beyond prevention. Prophylaxis would be much more efficient if a biochemical marker of myocardiocyte damage could be reliably used to stop further chemotherapy at the correct time before irreversible progressive 'macroscopic' damage becomes evident upon imaging. Work is currently progressing to identify the role of markers such as troponins and natriuretic peptides in this regard.

DIZE (dexamethasone, idarubicin, and continuous infusion of ifosfamide and etoposide): an effective and well-tolerated new regimen for patients with relapsed lymphoma

We performed a phase II study of dexamethasone, ifosfamide, idarubicin and etoposide (DIZE) in patients with relapsed or refractory Hodgkin's (HL) and non-Hodgkin's lymphoma (NHL). The regimen consisted of dexamethasone (20 mg i.v. days 1-4), idarubicin (8 mg/m2 i.v. days 1+2), continuous infusion (c.i.) of ifosfamide (1,000 mg/m2 days 1-4), and c.i. etoposide (60 mg/m2 days 1-4). G-CSF (5 microg/kg) was used to support neutrophil recovery from day 5. In older patients (> 60 years) the dosage of idarubicin and ifosfamide was reduced to 75% in the initial cycle. Fourty six patients (pts) were treated with a total of 131 cycles. Sixteen pts were primary resistant and 30 were relapsed. Median age was 54.3 years (range 22-75). The median number of different prior chemotherapies was 1.7 (range 1 to 5). 31/46 (67.4%) pts had advanced disease (stage III or IV); 19/46 had B symptoms. Of 43 evaluable pts the response rate was 58.1% including 11 complete remissions (CR) and 14 partial remissions (PR). Mean duration of response was 8 months (1-30+). DIZE was more effective in relapsed than in refractory high-grade NHL (74 % vs 16.6%; p < 0.001). Of four heavily pretreated pts with HL, one obtained CR and two PR (response rate 75%). Myelosuppression was generally moderate with a mean duration of leukocytopenia < 1,000/microl of 2.5 days (range 0-18) and of thrombocytopenia < 25,000/microl 1.5 days (range 0-17). One patient died of uncontrollable infection in treatment related neutropenia. No other serious toxicities apart from alopecia were observed. We conclude that DIZE is safe and effective in heavily pretreated pts with relapsed lymphoma. The continuous infusion of cytostatic drugs such as that used in the new DIZE protocol might reduce hematotoxicity.

A phase-II study with idarubicin, ifosfamide and VP-16 (IIVP-16) in patients with refractory or relapsed aggressive and high grade non-Hodgkin's lymphoma

We report a phase-II study of idarubicin, ifosphamide and etoposide (IIVP-16) in heavily pretreated patients with relapsed or refractory aggressive non-Hodgkin's lymphoma. The IIVP-16 regimen consisted of idarubicin (10 mg/m2 i.v. days 1 + 2 or days 1 + 8), ifosfamide (1000 mg/m2 i.v. days 1-5) and VP-16 (150 mg/m2 i.v. days 103). 40 patients were enrolled. Of 38 evaluable patients, 26 had centroblastic subtype, followed by lymphoblastic (6), immunoblastic (2), and other entities (4). 18 patients were primary resistant; 14 patients had early relapse (CR less than 12 months) and 8 patients late relapse (CR longer than 12 months). The median number of different prior chemotherapy regimens was 2 (range 1 to 6). 20 patients had received additional radiotherapy. The response-rate was 47.4% including 8 CR (21.1%) and 10 PR (26.3%). IIVP-16 was more effective in patients with relapsed disease when compared with patients with primary resistant disease (response rate 65% vs. 27.8%, p < 0.025). Leukopenia and thrombocytopenia were the major toxicities occurring in 73/107 (68.2%) and 57/107 (53.3%) of cycles (WHO grade IV). IIVP-16 is an effective regimen particularly in patients with unfavorable relapsed NHL.

Idarubicin and cytosine arabinoside reinduction therapy for children with multiple recurrent or refractory acute lymphoblastic leukemia: a Pediatric Oncology Group study

PURPOSE

This study was designed to determine the toxicity of and response to idarubicin and cytosine arabinoside in children and adolescents with acute lymphoblastic leukemia (ALL) who had refractory or recurrent bone marrow disease.

PATIENTS AND METHODS

Patients <21 years of age with ALL in second or later bone marrow relapse or refractory to induction therapy were eligible. Some patients also had concurrent central nervous system (CNS) relapse. Therapy consisted of cytosine arabinoside, 1 g/m2/day given as a 6-h infusion, followed by bolus idarubicin, 5 mg/m2/day, both daily for 6 days. Children achieving remission received maintenance therapy with 3 days of etoposide, 100 mg/m2/day, followed by ifosfamide, 2.8 g/m2/day, alternating every 3 weeks with 3 days of cytosine arabinoside and idarubicin in the dosages described earlier. All courses of therapy were followed by granulocyte colony-stimulating factor (G-CSF). Removal from study to undergo bone marrow transplantation (BMT) was encouraged.

RESULTS

Eighty-two patients were entered. There were 14 deaths (nine early), mostly from documented or presumed bacterial or fungal sepsis. Overall, 30 patients achieved complete remission (37%). These were mostly of brief duration--only one patient was still alive at 600+ days after BMT.

CONCLUSIONS

Cytosine arabinoside and idarubicin showed moderate activity in heavily pretreated children with ALL.

In-vivo and in-vitro mitochondrial membrane damages induced in mice by adriamycin and derivatives

A major limitation to a prolonged use of adriamycin (ADM) during a clinical treatment is its dose-dependent cardiotoxicity. This toxicity has been related to a general disturbance of the inner mitochondrial membrane structure and its essential biological functions, associated to the production of free radicals by the anthracyclines. 4'-Epiadriamycin (4'-epiADM), 4'-deoxyadriamycin (4'-deoxyADM), 4'-deoxy-4'-iodoadriamycin (4'-deoxy-4'-iodoADM) and 4'-demethoxydaunorubicin (4-demethoxyDNR) are ADM and daunorubicin (DNR) derivatives differing from their parent compounds by minor structural modifications. They are nevertheless documented as less cardiotoxic. Our purpose was to establish whether mitochondrial membrane damages induced in vivo in mice heart by those compounds are correlated with the free radical formation. Heart mitochondria of treated mice were isolated 48 h after a single drug injection in order to measure the acute mitochondrial toxicity. Enzymatic activities of complex I-III and complex IV of the mitochondrial respiratory chain, mitochondrial membrane fluidity and lipid peroxidation were measured. None of the ADM and DNR derivatives displayed a significant acute mitochondrial toxicity. A mitochondrial toxicity was however detected for 4-deoxyADM and 4-demethoxyDNR when drugs were given chronically, but it was strongly reduced as compared with ADM and DNR. Electron transfer between NADH and cytochrome c, formation of superoxide radicals and lipid peroxidation were measured in vitro for the various drugs. Comparison of the in-vivo and in-vitro results provides evidence that free radical production explains only partly the in-vivo toxicities.

Comparison of adriamycin and derivatives uptake into large unilamellar lipid vesicles in response to a membrane potential

The uptake of adriamycin (ADM) and several derivatives into large unilamellar vesicles (LUV) displaying a transmembrane potential and having a lipid composition close to that of the inner mitochondrial membrane has been measured. Drug association to neutral liposomes, made of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) (70:30, w/w) was shown to be potential-dependent: in the absence of potential, accumulation of drug was almost undetectable, whereas between 11 and 50 nmol of drug/mumol phospholipid, depending on the anthracycline used, was associated to LUV exhibiting a membrane potential after 1 h incubation. Association of drugs to LUV with a lipid composition closer to that of the inner mitochondrial (cardiolipin, CL, 20%; PC 50%; PE, 30%, w/w) and displaying a membrane potential is higher than with neutral vesicles (between 40 and 76 nmol of anthracycline/mumol phospholipid after 1 h incubation). Since it is known that ADM and derivatives have a high affinity for CL, a fraction of the associated drug may bind to CL on the outer side of the vesicles. This was confirmed by the fact that, in the absence of potential, between 40 and 56 nmol of anthracycline/mumol phospholipid was still associated to LUV containing CL. In order to discriminate between drug adsorbed at the surface of the LUV and drug accumulated inside the LUV, an anthracycline fluorescence quencher (I-) was used. It was shown on neutral LUV displaying a membrane potential, that between 55 and 81% of the associated drug is actually entrapped inside the vesicles, inaccessible to the quencher. These percentages decreased to between 41 and 68%, respectively, in the presence of LUV containing CL and exhibiting a membrane potential, whereas for LUV of the same composition but displaying no membrane potential almost all the associated drug is adsorbed on the outer face of the LUV, accessible to the quencher, and likely bound to CL. This study brings evidence that antitumour anthracyclines despite important structural homologies do not accumulate to the same extent into vesicles mimicking the lipid composition and the membrane potential of mitoplasts. This ability to reach the matrix compartment of mitochondria could partly explain the differences of cardiotoxicities associated to anthracyclines with closely related molecular structure.

Acute myeloid leukemia in the elderly: biological features and search for adequate treatment

AML in elderly patients is a heterogeneous disease which is characterized by a number of unfavorable features such as development, cytogenetics, blast cell differentiation, and poor treatment response. Specifically, the association between a higher incidence of unfavorable cytogenetic abnormalities in elderly patients and poor prognosis has been well documented. Low treatment response may be due to the specific biology of AML in this patient group, but also to host-specific factors such as higher treatment-related morbidity and mortality. Treatment tolerance cannot be judged on grounds of chronological age alone; risk factor analysis with regard to performance status, organ function, and underlying systemic disease need to be considered as well. For effective induction treatment in elderly patients, instant and intensive chemotherapy appears to be necessary, while delayed treatment or administration of supportive care alone provide unsatisfactory results. Standard-dose ara-C/anthracycline-containing regimens are the treatment of choice in patients with good performance status. However, patients with a WHO grading of greater than 3 might rather benefit from reduced regimens such as low-dose ara-C. At present, greatest improvement of AML treatment in elderly patients can be expected from an improvement of supportive care.

Idarubicin: a second-generation anthracycline

Because of its in vitro activity in leukemic cell lines and Phase I studies of acute leukemia, Phase II and III clinical trials with idarubicin hydrochloride were conducted in patients with acute lymphocytic leukemia or acute nonlymphocytic leukemia. In the Phase III comparative trials between the combinations of idarubicin and cytarabine and daunorubicin hydrochloride and cytarabine, the idarubicin/cytarabine combination resulted in significantly greater complete remission rates and longer overall survival in two of three studies conducted in the US. As a result, the Food and Drug Administration approved intravenous idarubicin with a Class 1A rating in September 1990 for use in combination with other antileukemic drugs (e.g., cytarabine) for the treatment of acute myelogenous leukemia in adults. The recommended dose of idarubicin is 12 mg/m2 daily for three days by slow intravenous injection in combination with cytarabine. Although idarubicin causes myelosuppression similar to that described with daunorubicin, the incidence of cardiotoxicity in animal models is lower. Idarubicin also has the advantage of oral administration, but the oral formulation of the drug remains investigational. The use of idarubicin in pediatric patients also remains to be established.