Etoposide. Current and future status

Heterogeneous graph inference with range constrainted L2,1-collaborative matrix factorization for small molecule-miRNA association prediction

MicroRNAs (miRNAs) play a vital role in regulating gene expression and various biological processes. As a result, they have been identified as effective targets for small molecule (SM) drugs in disease treatment. Heterogeneous graph inference stands as a classical approach for predicting SM-miRNA associations, showcasing commendable convergence accuracy and speed. However, most existing methods do not adequately address the inherent sparsity in SM-miRNA association networks, and imprecise SM/miRNA similarity metrics reduce the accuracy of predicting SM-miRNA associations. In this research, we proposed a heterogeneous graph inference with range constrained L2,1-collaborative matrix factorization (HGIRCLMF) method to predict potential SM-miRNA associations. First, we computed the multi-source similarities of SM/miRNA and integrated these similarity information into a comprehensive SM/miRNA similarity. This step improved the accuracy of SM and miRNA similarity, ensuring reliability for the subsequent inference of the heterogeneity map. Second, we used a range constrained L2,1-collaborative matrix factorization (RCLMF) model to pre-populate the SM-miRNA association matrix with missing values. In this step, we developed a novel matrix decomposition method that enhances the robustness and formative nature of SM-miRNA edges between SM networks and miRNA networks. Next, we built a well-established SM-miRNA heterogeneous network utilizing the processed biological information. Finally, HGIRCLMF used this network data to infer unknown association pair scores. We implemented four cross-validation experiments on two distinct datasets, and HGIRCLMF acquired the highest areas under the curve, surpassing six state-of-the-art computational approaches. Furthermore, we performed three case studies to validate the predictive power of our method in practical application.

Facile synthesis of an acid-responsive cinnamaldehyde-pendant polycarbonate for enhancing the anticancer efficacy of etoposide via glutathione depletion

Glutathione (GSH) is an important antioxidant that maintains cellular redox homeostasis and significantly contributes to resistance against various chemotherapeutic agents. To address the challenge of GSH-mediated drug resistance in etoposide (ETS), we developed a facile synthetic method to prepare a biocompatible acid-responsive polycarbonate (PEG-PCA) containing cinnamaldehyde (CA), a potent GSH-depleting agent, as a side chain using nontoxic raw materials. This polymer self-assembled in aqueous solutions to form nanoparticles (ETS@PCA) that encapsulated ETS, enhancing its water solubility and enabling tumor-targeted delivery. In vitro studies demonstrated that ETS@PCA could respond to the acidic tumor microenvironment, releasing CA to rapidly deplete GSH levels. Consequently, ETS@PCA exhibited superior cytotoxicity compared to free ETS. Furthermore, in vivo experiments corroborated the enhanced tumor inhibitory effects of ETS@PCA.

A high-throughput 384-well CometChip platform reveals a role for 3-methyladenine in the cellular response to etoposide-induced DNA damage

The Comet or single-cell gel electrophoresis assay is a highly sensitive method to measure cellular, nuclear genome damage. However, low throughput can limit its application for large-scale studies. To overcome these limitations, a 96-well CometChip platform was recently developed that increases throughput and reduces variation due to simultaneous processing and automated analysis of 96 samples. To advance throughput further, we developed a 384-well CometChip platform that allows analysis of ∼100 cells per well. The 384-well CometChip extends the capacity by 4-fold as compared to the 96-well system, enhancing application for larger DNA damage analysis studies. The overall sensitivity of the 384-well CometChip is consistent with that of the 96-well system, sensitive to genotoxin exposure and to loss of DNA repair capacity. We then applied the 384-well platform to screen a library of protein kinase inhibitors to probe each as enhancers of etoposide induced DNA damage. Here, we found that 3-methyladenine significantly increased levels of etoposide-induced DNA damage. Our results suggest that a 384-well CometChip is useful for large-scale DNA damage analyses, which may have increased potential in the evaluation of chemotherapy efficacy, compound library screens, population-based analyses of genome damage and evaluating the impact of environmental genotoxins on genome integrity.

Ifosfamide and Etoposide in Previously Treated Patients with Advanced Breast Cancer

Aims and background

Ifosfamide is an active alkylating agent in the treatment of breast cancer, as a first-line therapy and in advanced disease. Since the combination of etoposide with an alkylating agent produces a synergistic and tolerable activity in various malignancies, in the present study, ifosfamide and etoposide were administered to patients with advanced breast cancer to evaluate the response characteristics and the toxicity profile.

Study design

The combination of ifosfamide, mesna and etoposide was prospectively administered to 41 previously treated patients with stage IV breast carcinoma. The treatment schedule consisted of ifosfamide, 1500 mg/m2, infused over 24 hrs with 1500 mg/m2 mesna on days 1 to 5 and 120 mg/m2 etoposide, infused over 1 hr on days 1 to 3, to be repeated every 4th week.

Results

After a median follow-up of 10 months, an objective response rate of 23% (overall 2.5% complete remission and 20.5% partial remission) and a median response duration of 5.3 months were obtained in 39 assessable patients. The non-responder group consisted of 28.3% stable disease and 48.7% progressive disease. The prior status of chemotherapy was the only significant prognostic factor with an impact on the response rate. The overall toxicity was generally mild, with grade 3 myelotoxicity encountered in 25.7% of patients.

Conclusions

The tolerable side effect profile of the ifosfamide and etoposide combination might be advantageous as regards the quality of life. To improve the rate and/or the duration of response and to clarify the precise role of the ifosfamide-etoposide combination in previously treated advanced breast cancer, further trials are warranted.

Inhibition of polo-like kinase 4 (PLK4): a new therapeutic option for rhabdoid tumors and pediatric medulloblastoma

Rhabdoid tumors (RT) are highly aggressive and vastly unresponsive embryonal tumors. They are the most common malignant CNS tumors in infants below 6 months of age. Medulloblastomas (MB) are embryonal tumors that arise in the cerebellum and are the most frequent pediatric malignant brain tumors. Despite the advances in recent years, especially for the most favorable molecular subtypes of MB, the prognosis of patients with embryonal tumors remains modest with treatment related toxicity dreadfully high. Therefore, new targeted therapies are needed. The polo-like kinase 4 (PLK4) is a critical regulator of centriole duplication and consequently, mitotic progression. We previously established that PLK4 is overexpressed in RT and MB. We also demonstrated that inhibiting PLK4 with a small molecule inhibitor resulted in impairment of proliferation, survival, migration and invasion of RT cells. Here, we showed in MB the same effects that we previously described for RT. We also demonstrated that PLK4 inhibition induced apoptosis, senescence and polyploidy in RT and MB cells, thereby increasing the susceptibility of cancer cells to DNA-damaging agents. In order to test the hypothesis that PLK4 is a CNS druggable target, we demonstrated efficacy with oral administration to an orthotropic xenograft model. Based on these results, we postulate that targeting PLK4 with small-molecule inhibitors could be a novel strategy for the treatment of RT and MB and that PLK4 inhibitors (PLK4i) might be promising agents to be used solo or in combination with cytotoxic agents.

Antitumor effect of Deoxypodophyllotoxin on human breast cancer xenograft transplanted in BALB/c nude mice model

Recently, biologically active compounds isolated from plants used in herbal medicine have been the center of interest. Deoxypodophyllotoxin (DPT), structurally closely related to the lignan podophyllotoxin, was found to be a potent antitumor and antiproliferative agent, in several tumor cells, in vitro. However, DPT has not been used clinically yet because of the lack of in vivo studies. This study is the first report demonstrating the antitumor effect of DPT on MDA-MB-231 human breast cancer xenografts in nude mice. DPT, significantly, inhibited the growth of MDA-MB-231 xenograft in BALB/c nude mice. The T/C value (the value of the relative tumor volume of treatment group compared to the control group) of groups treated with 5, 10, and 20 mg/kg of intravenous DPT-HP-β-CD was 42.87%, 34.04% and 9.63%, respectively, suggesting the positive antitumor activity of DPT. In addition, the antitumor effect of DPT-HP-β-CD (20 mg/kg) in human breast cancer MDA-MB-231 xenograft was more effective than etoposide (VP-16) (20 mg/kg) and docetaxel (20 mg/kg). These findings suggest that this drug is a promising chemotherapy candidate against human breast carcinoma.

Inhibition of tumor angiogenesis by oral etoposide

The chemotherapeutic agent etoposide is a topoisomerase II inhibitor widely used for cancer therapy. Low-dose oral etoposide, administered at close regular intervals, has potent anti-tumor activity in patients who are refractory to intravenous etoposide; however, the mechanism remains unclear. Since endothelial cells may be more sensitive than tumor cells to chemotherapy agents, we determined the effects of etoposide alone and in combination with oral cyclooxygenase-2 inhibitors and peroxisome-proliferator activated receptor γ ligands on angiogenesis and tumor growth in xenograft tumor models. Optimal anti-angiogenic (metronomic) and anti-tumor doses of etoposide on angiogenesis, primary tumor growth and metastasis were established alone and in combination therapy. Etoposide inhibited endothelial and tumor cell proliferation, decreased vascular endothelial growth factor (VEGF) production by tumor cells and suppressed endothelial tube formation at non-cytotoxic concentrations. In our in vivo studies, oral etoposide inhibited fibroblast growth factor 2 and VEGF-induced corneal neovascularization, VEGF-induced vascular permeability and increased levels of the endogenous angiogenesis inhibitor endostatin in mice. In addition, etoposide inhibited Lewis lung carcinoma (LLC) and human glioblastoma (U87) primary tumor growth as well as spontaneous lung metastasis in a LLC resection model. Furthermore, etoposide had synergistic anti-tumor activity in combination with celecoxib and rosiglitazone, which are also oral anti-angiogenic and anti-tumor agents. Etoposide inhibits angiogenesis in vitro and in vivo by indirect and direct mechanisms of action. Combining etoposide with celecoxib and rosiglitazone increases its efficacy and merits further investigation in future clinical trials to determine the potential usefulness of etoposide in combinatory anti-angiogenic chemotherapy.

Antineoplastic activity of idazoxan hydrochloride

PURPOSE

Idazoxan hydrochloride (IDA) is a 241 molecular weight imidazoline and adrenoreceptor ligand. It binds to mitochondrial membranes and promotes apoptosis of pancreatic beta cells. Since IDA has not been tested against tumor cells, the purpose of our study was to determine if IDA has antineoplastic activity.

METHODS

We used the conversion of a soluble tetrazolium salt to an insoluble formazan precipitate and differential staining cytotoxicity assays to determine if IDA was cytotoxic to cell lines of murine lung cancer and human prostate cancer, as well as to a variety of fresh human tumor samples. We used flow cytometry to analyze cell death and calreticulin expression.

RESULTS

IDA is cytotoxic to both cell lines and against aliquots of specimens of breast, gastric, lung, ovarian and prostate cancers as well as non-Hodgkin's lymphoma. It produces apoptotic cell death and promotes calreticulin expression, suggesting that IDA might be immunomodulatory in vivo.

CONCLUSION

We anticipate that IDA will be clinically useful in cancer treatment.

Etoposide attenuates zymosan-induced shock in mice

Zymosan-induced generalized inflammation is a convenient model to study the process of acute and chronic inflammatory processes resulting in multiple organ dysfunction syndrome. Macrophages as a source of many pro-inflammatory mediators are the major players in shock and further organ failure. Etoposide is a cytostatic drug known to reduce macrophages and monocytes in blood circulation. In the present study we have investigated whether the ability of etoposide to diminish macrophage number would have an impact on the course of zymosan-induced shock. The drug injected at a dose of 10 mg/kg 1 day before zymosan, significantly reduced the mortality and decreased the organ toxicity in Balb/c mice. Simultaneously, an inhibition of TNF-alpha production by alveolar and peritoneal macrophages was observed. Etoposide administered into mice with severe combined immunodeficiency (SCID) did not change the survival rate and had a little influence on organ toxicity. Our findings suggest that the beneficial action of etoposide might be attributed to the reduction of macrophages and alteration of their functions. Its effect depends on the presence of functional T and B lymphocytes. The results deserve further investigation of etoposide as a perspective therapeutic tool for inhibiting the excessive inflammatory response and to be helpful for revealing mechanisms of shock development.

Cytotoxicity, apoptosis induction, and mitotic arrest by a novel podophyllotoxin glucoside, 4DPG, in tumor cells

AIM

To define the in vitro cytotoxic activities of 4-demethyl-picropodophyllotoxin 7'-O-beta-D-glucopyranoside (4DPG), a new podophyllotoxin glucoside.

METHODS

Antiproliferation activity was measured in several tumor cell lines by using the microculture tetrazolium MTT assays. Cell cycle distribution was analyzed using flow cytometry and mitosis index assays. Furthermore, transmission electron microscopy, TUNEL, DNA agarose electrophoresis, and activated caspase-3 were used to analyze the induction of apoptotic cell death. Moreover, intracellular changes in the cytoskeleton were detected using immunocytochemistry.

RESULTS

4DPG effectively inhibited the proliferation of cancer cells (HeLa, CNE, SH-SY5Y, and K562 cell lines). For the K562 cell line, the antiproliferation effect of 4DPG was much more potent than that of etoposide (IC50 value: 7.79 x 10(-9) mol/L for 4DPG vs 2.23 x 10(-5) mol/L for etoposide). Further, 4DPG blocked the cell cycle in the mitotic phase. The induction of apoptosis and elevated levels of activated caspase-3 were confirmed in cells treated with 4DPG. The microtubule skeleton of HeLa cells was disrupted immediately after treatment with 4DPG.

CONCLUSION

The cytotoxicity of 4DPG is due to its inhibition of the microtubule assembly of cancer cells at a low concentration, thus inducing apoptosis. These properties qualify 4DPG to be a potential antitumor drug.

Prodrug Mono Therapy: synthesis and biological evaluation of an etoposide glucuronide-prodrug

A glucuronide-based prodrug of etoposide has been synthesized for a Prodrug Mono Therapy strategy. The aim is to selectively liberate the active compound by beta-D-glucuronidase already present in necrotic tumours. Outside from these sites, this enzyme is known to be localised inside the lysosomes. The three components of this prodrug are the glucuronic acid (substrate of the enzyme), the spacer (for a faster cleavage), and the active etoposide. In vitro, the prodrug was shown to be less cytotoxic and more water-soluble than etoposide itself. Finally, in the presence of the beta-D-glucuronidase, cleavage of the prodrug with complete release of the drug has been observed.

Microtubule damaging agents induce apoptosis in HL 60 cells and G2/M cell cycle arrest in HT 29 cells

Microtubule damaging agents (such as paclitaxel and nocodazole (ND)) have been used in the clinical cancer chemotherapy. However, the molecular mechanisms of these agents in the induction of anti-cancer activity are still unclear. In the present study, we demonstrated that 0.2 microM podophyllotoxin (PDP) induced the occurrence of apoptosis in human leukemic (HL 60) cells and cell cycle arrest at the G2/M phase in HT 29 cells. Our results suggest that the PDP-induced G2/M arrest in HT 29 cells was through the intracellular events including (a) inhibition of normal mitotic spindle formation, (b) elevation of cyclin B1/cdc2 kinase activity, (c) concomitant increases in cdc 25 A phosphatase and cdk 7 kinase activity, and (d) down-regulation of the wee-1 protein expression. On the other hand, activations of the caspases 3, 8, and 9, Bcl-2 hyper-phosphorylation, and increased leakage of cytochrome c from mitochondria into cytosolic fraction were detected in the PDP-treated HL 60 cells. These listed intracellular events were interpreted to lead to the apoptosis observed in PDP-treated HL 60 cells. We further demonstrated that activation of c-jun N-terminal kinase (JNK) signaling pathway may play an important role in the PDP-induced Bcl-2 phosphorylation and apoptosis in HL 60 cells as evidenced by the JNK specific anti-sense oligonucleotide experiment. Our results demonstrated that the occurrence of apoptosis or G2/M cell cycle arrest induced by microtubule damaging agents in different cancer cells was through independent mechanisms. The results from the present study highlight the molecular mechanisms underlying of the PDP-induced anti-cancer activity.

Intra-arterial cisplatin plus oral etoposide for the treatment of recurrent malignant glioma: a phase II study

Twenty-five adults with recurrent malignant glioma were enrolled into a phase II clinical study. All patients had undergone surgical resection and had failed radiotherapy and first-line treatment with nitrosourea-based chemotherapy; five had failed second-line chemotherapy. Our objective was to test the efficacy of combining intra-arterially (i.a.) infused cisplatin and oral etoposide. Using conventional angiographic technique to access anterior/posterior cerebral circulation, cisplatin 60 mg/m2 was administered by i.a. infusion on day 1 of treatment. Oral etoposide 50 mg/m2/day was given days 1-21, with a 7 day rest interval between courses. Response to treatment was evaluated in 20 patients. Two patients with anaplastic astrocytoma had partial responses (PR) and six patients experienced stable disease (SD) for an overall response rate (PR +/- SD) of 40%. The median time to disease progression (MTP) following treatment for the responder subgroup was 18 weeks. The median survival time from treatment (MST) for the responders (n = 8) and non-responders (n = 12) was 56.5 weeks and 11 weeks, respectively. Combined i.a. cisplatin and oral etoposide was well-tolerated, but produced an objective response in only a minority of patients. Those considered responders (PR + SD) experienced significant survival advantage when compared to the non-responders. Nonetheless, i.a. delivery of chemotherapy is an expensive and technologically burdensome treatment for most patients to access, requiring proximity to a major center with neuro-oncological and neuroradiological clinical services. This is of special concern for patients suffering recurrent disease with progressive neurological symptoms at a time in their course when quality of life must be safeguarded and palliation of symptoms should be the therapeutic goal. Despite the efforts of previous investigators to use this combination of agents to treat recurrent malignant glioma, we cannot recommend the use of i.a. chemotherapy for salvage treatment of this disease.

Protracted results of dose-intensive therapy using cyclophosphamide, carmustine, and continuous infusion etoposide with autologous stem cell support in patients with relapse or refractory Hodgkin's disease: a phase II study from the North American Marrow Transplant Group

To determine the long-term results of high-dose chemotherapy and stem cell support in relapsed or primary refractory Hodgkin disease patients. One hundred and thirty-one patients with relapsed or primary refractory Hodgkin's disease were treated with a dose-intensive therapy protocol consisting of etoposide (2400 mg/m2 continuous intravenous infusion) cyclophosphamide (7200 mg/m2 intravenously), and carmustine (300-600 mg/m2 intravenously) CBVi. All patients had previously failed conventional chemoradiotherapy. Severe toxicities were related to infectious, hepatic, and pulmonary complications. Fatal, regimen-related toxicity was 19%; liver and lung dysfunction, as well as infection, were the most frequent problems. Ninety-one (69%) of the patients achieved a complete response (CR) (95% CI = 59% to 75%) after CBVi and autologous stem cell infusion. With a median follow-up of 5.1 years (range 3.0 to 9.5 years), overall and event-free survival are 44% (95% CI = 33% to 47%) and 38% (95% CI = 28% to 46%) respectively. While univariate analysis did not reveal a statistically significant variable to predict a better response, responsiveness to therapy demonstrated a trend. We conclude that CBVi is an effective therapy for relapsed or refractory Hodgkin's disease, producing long-term, durable remissions.

A cycloplatinated compound of p-isopropylbenzaldehyde thiosemicarbazone and its chloro-bridged derivative induce apoptosis in cis-DDP resistant cells which overexpress the H-ras oncogene

cis-Diamminedichloroplatinum(II) (cis-DDP) is a widely used antitumour drug which produces important damage on the DNA inducing apoptosis in several cell lines. We have analyzed the cytotoxic activity of novel cyclometallated complexes of p-isopropylbenzaldehyde thiosemicarbazone (p-is.TSCN) and their dimeric chloro-bridged derivatives in murine keratinocytes transformed by the H-ras oncogene which are resistant to cis-DDP (Pam-ras cells). The data show that, in contrast with cis-DDP, the tetrameric cycloplatinated complex [Pt(p-is.TSCN)]4 and its dimeric chloro-bridged derivative [Pt(microCl)(p-is.TSCN)]2 have a good in vitro therapeutic index when comparing the cytotoxicity in Pam-ras cells to normal murine keratinocytes (Pam 212 cells) since they induce cell death in Pam-ras cells at drug concentrations significantly lower than those needed to kill Pam 212 cells. At equitoxic doses (IC90), both complexes produce characteristic features of apoptosis in Pam-ras cells together with a drastic decrease in levels of H-ras protein. These effects are not observed when the cells are treated with the IC90 of the cis-DDP drug nor the p-is.TSCN ligand. Altogether, these results suggest that the platinum compounds [Pt(p-is.TSCN)]4 and [Pt(microCl)(p-is.TSCN)]2 might have potential as antitumour agents in view of their specific induction of apoptosis in cis-DDP resistant cells.

Identification of the genes responsive to etoposide-induced apoptosis: application of DNA chip technology

DNA chip technology was used in an attempt to identify target genes responsible for apoptosis induced by etoposide, a p53 activating topoisomerase II inhibitor used clinically as an antitumor agent. 62 Individual mRNAs whose mass changed significantly were identified after screening oligonucleotide arrays capable of detecting 6591 unique human mRNA species. 12 (Nine induced and three repressed) of the etoposide-responsive genes were further studied by Northern analysis and an agreement rate of 92%, was reached. Among the 12 genes studied, two (WAF1/p21 and PCNA) are known p53 regulatory genes, two (glutathione peroxidase and S100A2 calcium-binding protein) appear to be the novel p53 target genes and the others appear to be p53-independent. Based upon these findings, the signalling pathways that possibly mediate etoposide-induced apoptosis are proposed.

Etoposide: four decades of development of a topoisomerase II inhibitor

Podophyllin-containing materials have been used as folk medicines for centuries. In the 1950s, scientists began a search to identify a more effective podophyllotoxin derivative. These efforts eventually resulted in the development of a new class of antineoplastic agents which target the DNA unwinding enzyme, topoisomerase II. The history of the development of one of the first identified topoisomerase II inhibitors, etoposide, is reviewed in this paper. Critical developments in etoposide's mechanism of action, pharmacology and administration schedule are summarised. The clinical benefits of the recently marketed etoposide prodrug, etoposide phosphate (Etopophos) are also detailed. The current status of other clinically approved anticancer agents which target topoisomerase II is briefly reviewed.

Treatment of recurrent malignant supratentorial gliomas with the association of carboplatin and etoposide: a phase II study

Thirty one patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of carboplatin (CBDCA) and etoposide (VP16) at tumor progression. Carboplatin and etoposide (CE) were given, each at a dose of 100 mg/m2/day from day 1 to 3. The response was evaluated at each course and a minimum of three course was required to definite stable patient. Tolerance was evaluated in 31 patients. None had renal or auditory toxicity. Side effects consisted of grade III hematologic toxicity in 6 patients (19%), and grade III hepatic toxicity in one patient. No grade IV WHO toxicity was observed. All 31 patients could be evaluated for therapeutic response. A partial response was noted in 4 patients during 13, 34 +, 35 + and 51 + weeks. Ten patients had stable disease after a minimum of 3 courses (19 to 37 weeks). The rate of partial response (PR) and stabilisation (S) was 45% (14/31). The median time to tumor progression (MTTP) for responding and stable patients was 28 weeks. The median survival time (ST) for the entire group was 45 weeks and over 51 weeks for PR and S patients.

High-dose carboplatin, etoposide and melphalan (CEM) with peripheral blood progenitor cell support as late intensification for high-risk cancer: non-haematological, haematological toxicities and role of growth factor administration

The present report describes the non-haematological toxicity and the influence of growth factor administration on haematological toxicity and haematopoietic recovery observed after high-dose carboplatin (1200 mg m(-2)), etoposide (900 mg m(-2)) and melphalan (100 mg m(-2)) (CEM) followed by peripheral blood progenitor cell transplantation (PBPCT) in 40 patients with high-risk cancer during their first-line treatment. PBPCs were collected during the previous outpatient induction chemotherapy programme by leukaphereses. CEM administration with PBPCT was associated with low non-haematological toxicity and the only significant toxicity consisted of a reversible grade III/IV increase in liver enzymes in 32% of the patients. Haematopoietic recovery was very fast in all patients and the administration of granulocyte colony-stimulating factor (G-CSF) plus erythropoietin (EPO) or granulocyte-macrophage colony-stimulating factor (GM-CSF) plus EPO after PBPCT significantly reduced haematological toxicity, abrogated antibiotic administration during neutropenia and significantly reduced hospital stay and patient's hospital charge compared with patients treated with PBPCT only. None of the patients died early of CEM plus PBPCT-related complications. Low non-haematological toxicity and accelerated haematopoietic recovery renders CEM with PBPC/growth factor support an acceptable therapeutic approach in an adjuvant or neoadjuvant setting.

Treatment of recurrent malignant supratentorial gliomas with ifosfamide, carboplatin and etoposide: a phase II study

Thirty-six patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of ifosfamide, carboplatin and etoposide (ICE) at tumour progression. Carboplatin and etoposide were both given at a dose of 75-100 mg/m2/day for 3 days, whereas ifosfamide doses ranged from 750 mg/m2/day to 1500 mg/m2/ day for 3 days, according to haematological tolerance. Treatment was repeated every 4 weeks. A minimum of three courses was required to evaluate the response unless the patient had rapid tumour progression. Grade III and IV haematological toxicity occurred in 15 patients (42%) and was lethal in one patient. Grade II hepatic toxicity was observed in one patient. Five complete (CR) and five partial responses (PR) were noted. 9 patients had stable disease (SD) after a minimum of three courses. CR + PR + SD was 53% (19/36). The median time to tumour progression (MTTP) was 13 weeks. Median survival (MST) was 29 weeks (44 weeks for R + S patients and 17 weeks for patients with progressing disease). This study suggests that the ICE combination is active in recurrent supratentorial malignant gliomas after failure of surgery, radiation therapy and chemotherapy, but at the cost of substantial haematological toxicity.

Combination toxicity of etoposide (VP-16) and photosensitisation with a water-soluble aluminium phthalocyanine in K562 human leukaemic cells

Etoposide (VP-16) is an anti-cancer drug commonly used against several types of tumours and leukaemia, either alone or in combination chemotherapy. Photodynamic therapy (PDT) is another, relatively new modality for treatment of various malignancies. The interactions between VP-16 and PDT, using aluminium tetrasulphophthalocyanine as photosensitiser, in K562 human leukaemic cells were investigated. Cell responses to individual and combined drug treatment under different experimental conditions revealed synergistic drug toxicity. The latter was evident from various events of cell response, including supra-additive accumulation of cells in G2/M cell cycle phase and endonucleolytic DNA fragmentation (apoptosis). The involvement of the cellular antioxidant system in the synergistic interactions of photosensitisation and VP-16 is proposed.

High-dose, brief duration, multiagent chemotherapy for metastatic breast cancer

BACKGROUND

The authors evaluated a high-intensity inpatient regimen using augmented but subtransplantation doses of multiple agents in patients with metastatic breast cancer. Two high-dose courses were given in an attempt to improve the efficacy of high-dose regimens using a single course.

METHODS

Forty women received treatment between October 1988 and October 1991. The median age was 38 years (range, 24-56 years). Twenty-five patients were receiving their first chemotherapy for metastatic disease; 15 patients had received one or more prior regimens. The patients received two courses of chemotherapy, which consisted of the following: cyclophosphamide 1500 mg/m2 intravenously (i.v.) on days 1 and 2; doxorubicin 45 mg/m2 i.v. on days 1 and 2; cisplatin 20 mg/m2 i.v. on days 1, 2, 3, 8, 9, and 10; 5-fluorouracil 1000 mg/m2 on days 8, 9, and 10 (continuous infusion); methotrexate 100 mg/m2 i.v. on days 15 and 22; leucovorin 15 mg/m2 i.v. or by mouth for four doses beginning 24 hours after methotrexate. Etoposide 400 mg/m2 i.v. on days 1, 2, and 3 was substituted for doxorubicin in 14 patients who had received prior doxorubicin.

RESULTS

Twenty-nine of 40 patients (73%) had objective response to therapy, with 10 (25%) complete responses. Four patients who obtained a complete response remain disease-free at 14, 21, 28, and 32 months, respectively; all of these patients received this regimen as first-line therapy for metastatic disease. Myelosuppression was severe, with median durations of leukocytes less than 1000/microliters and platelets less than 50,000/microliters of 15 days (range, 7-48 days) and 13 days (range, 3-49 days), respectively. Moderate or severe mucositis occurred in 56 of 68 courses. Four patients (10%) had treatment-related deaths.

CONCLUSIONS

This regimen produced high overall response and complete response rates compared with standard regimens. However, only 15% of patients who received this therapy as first-line treatment for metastatic breast cancer remain disease-free, and median response duration was shorter than that reported using high-dose therapy with bone marrow support. Toxicity with this regimen was greater than anticipated, although myelosuppression and stomatitis would be reduced by the use of cytokines. This regimen does not improve results achieved with standard therapy sufficiently to justify its toxicity and expense.

Pharmacodynamics and long-term toxicity of etoposide

Etoposide has been used in the treatment of a wide variety of neoplasms, including small-cell lung cancer, Kaposi's sarcoma, testicular cancer, acute leukemia, and lymphoma. Its current therapeutic use is limited by myelosuppression, particularly neutropenia. Pharmacodynamic studies of etoposide show that this toxicity can be modeled using a modified Hill equation and that the dose intensity of etoposide can be successfully increased by adaptive control using this model. Significant influences on the degree of myelosuppression include the pretreatment leukocyte count, the performance status, the extent of prior erythrocyte transfusions, and the serum albumin level. In the past 7 years, interest has developed in a distinct subset of acute nonlymphocytic leukemia that is associated with prior exposure to etoposide. This syndrome has been described in several studies and is characterized by the lack of a preleukemic phase, M4 or M5 morphology, and distinct translocations involving the chromosome 11q23 region. In addition, secondary acute lymphocytic leukemias (involving 11q23) have also been associated with prior epipodophyllotoxin exposure.

The current and future place of vinorelbine in cancer therapy

Vinorelbine is a new semisynthetic vinca alkaloid that differs chemically from vinblastine by a substitution of the catharanthine moiety. The antitumour activity of vinorelbine against murine tumours, human malignant cell lines and human tumour xenografts in nude mice is evidence of its powerful cytostatic activity against all tumour types. Phase I and phase II studies of intravenous vinorelbine, administered weekly as a single agent or in combination chemotherapy, have been conducted since 1985. Results suggest that vinorelbine has high activity in non-small cell lung cancer (with an overall response rate of 33 to 65%), breast cancer (overall response rate of 46 to 78%) and cisplatin-resistant ovarian carcinoma (over-all response rate of 16% and 35% with single-agent and combination therapy, respectively). In Hodgkin's disease, vinorelbine as a single agent demonstrates high activity, with overall responses ranging from 34 to 90%. Recent phase II studies assessing vinorelbine administered by continuous infusion or orally show promising response rates; however, further trials are needed to validate these preliminary results.