The ex vivo effect of high concentrations of doxorubicin on recurrent ovarian carcinoma

The cardiotoxicity of anthracyclines has largely prevented dose intensification, but the use of liposomal preparations (e.g. Caelyx/Doxil) allows much higher intra-tumoral concentrations to be achieved without cardiotoxicity. However, it is uncertain how much this will improve response rates over standard anthracycline therapy. The ATP-based chemosensitivity assay (ATP-TCA) has been used to develop new regimens for several tumor types, to investigate the molecular basis of chemosensitivity and shows considerable promise as a clinical method for individualizing chemotherapy. In this study, we have used the ATP-TCA to determine the concentration responsiveness of tumor-derived cells to concentrations of doxorubicin. The 22 tumor samples included were obtained from 20 heavily pretreated patients with recurrent ovarian cancer. Eight had previous anthracycline exposure, four as part of the CAP regimen. The results show more than 95% inhibition at clinically achievable concentrations in 11 of 22 tumors tested. Of the rest, seven showed a plateau effect between 80 and 95% inhibition, suggesting that there might be a subset of resistant cells present that is not inhibited by high concentrations of doxorubicin. Two tumors showed complete resistance and neither of these had previously received anthracycline therapy. As it has been suggested that gemcitabine might enhance anthracycline sensitivity in combination and we have had good results with gemcitabine modulation of alkylating agents in the assay, we have tested the combination of doxorubicin+gemcitabine under assay conditions in 11 tumors with little indication of improvement. In conclusion, doxorubicin at concentrations achievable with liposomal preparations shows strong ex vivo activity against pretreated recurrent ovarian cancer in just over half of the cases tested.     

Rapid up-regulation of cyclooxygenase-2 by 5-fluorouracil in human solid tumors

Inhibition of cyclooxygenase (COX)-2 has been associated with reduced growth of malignant cells. Current therapy of gastrointestinal carcinomas involves the use of 5-fluorouracil (5-FU)-based chemotherapy and we have therefore studied the effect of this agent on the expression of COX-2. COX-2 expression was measured by quantitative RT-PCR in biopsies from a series of 14 esophageal carcinomas, six of which had paired samples taken before and after chemotherapy, and in tumor-derived cells exposed to 5-FU in vitro from a series of 44 tumors, including breast, ovarian, esophageal and colonic carcinomas. COX-2 expression was increased by exposure to 5-FU or 5-FU combination chemotherapy in all the tumor types studied, whether measured in biopsies taken before and after 5-FU-based chemotherapy (4-fold increase, p<0.015) or in primary cells exposed to drugs in vitro (24-fold increase, p<0.001). A modest increase of COX-2 mRNA was also seen after in vitro treatment of cells with cisplatin. In contrast, doxorubicin and paclitaxel caused no up-regulation in vitro, while irinotecan caused inhibition of COX-2 (2.7-fold decrease, p<0.01). These data provide a molecular rationale for clinical trials of combination chemotherapy with COX-2 inhibitors.     

Pegylated liposomal doxorubicin: a review of its use in metastatic breast cancer, ovarian cancer, multiple myeloma and AIDS-related Kaposi's sarcoma

Pegylated liposomal doxorubicin (Caelyx?, Doxil?) represents an improved formulation of conventional doxorubicin, with reduced cardiotoxicity and an improved pharmacokinetic profile. This article reviews the efficacy and tolerability of pegylated liposomal doxorubicin in metastatic breast cancer, progressive ovarian cancer, relapsed or refractory multiple myeloma and AIDS-related Kaposi's sarcoma, as well as summarizing its pharmacological properties. In three randomized, open-label, multicentre trials, monotherapy with pegylated liposomal doxorubicin was as effective as doxorubicin or capecitabine in the first-line treatment of metastatic breast cancer, and as effective as vinorelbine or combination mitomycin plus vinblastine in taxane-refractory metastatic breast cancer. Pegylated liposomal doxorubicin alone was as effective as topotecan or gemcitabine alone in patients with progressive ovarian cancer resistant or refractory to platinum- or paclitaxel-based therapy, according to the results of three randomized multicentre trials. In addition, in patients with progressive ovarian cancer who had received prior platinum-based therapy, progression-free survival was significantly longer with pegylated liposomal doxorubicin plus carboplatin than with paclitaxel plus carboplatin, according to the results of a randomized, open-label multicentre trial. Combination therapy with pegylated liposomal doxorubicin plus bortezomib was more effective than bortezomib alone in patients with relapsed or refractory multiple myeloma, according to the results of a randomized, open-label, multinational trial. Randomized multinational trials also demonstrated the efficacy of pegylated liposomal doxorubicin in patients with advanced AIDS-related Kaposi's sarcoma. Pegylated liposomal doxorubicin exhibited a relatively favourable safety profile compared with conventional doxorubicin and other available chemotherapy agents. The most common treatment-related adverse events included myelosuppression, palmar-plantar erythrodysesthesia and stomatitis, although these are manageable with appropriate supportive measures. To conclude, pegylated liposomal doxorubicin is a useful option in the treatment of various malignancies, including metastatic breast cancer, ovarian cancer, multiple myeloma and AIDS-related Kaposi's sarcoma.     

Pegylated liposomal doxorubicin in the treatment of cancers of the breast and ovary

Peglyated liposomal doxorubicin was developed to maintain or enhance the demonstrated antineoplastic effects of doxorubicin, while improving the toxicity profile associated with this important cytotoxic agent. Accumulating clinical data have confirmed the activity of pegylated liposomal doxorubicin in cancers of the breast and ovary. Furthermore, Phase II and III trial experience has revealed that the drug produces objective responses comparable in rate and duration to doxorubicin and other single agents employed in metastatic breast cancer. In recurrent and platinum-resistant ovarian cancer, single-agent pegylated liposomal doxorubicin has assumed an important role in routine patient management.     

Pegylated liposomal doxorubicin in the treatment of cancers of the breast and ovary

Peglyated liposomal doxorubicin was developed to maintain or enhance the demonstrated antineoplastic effects of doxorubicin, while improving the toxicity profile associated with this important cytotoxic agent. Accumulating clinical data have confirmed the activity of pegylated liposomal doxorubicin in cancers of the breast and ovary. Furthermore, Phase II and III trial experience has revealed that the drug produces objective responses comparable in rate and duration to doxorubicin and other single agents employed in metastatic breast cancer. In recurrent and platinum-resistant ovarian cancer, single-agent pegylated liposomal doxorubicin has assumed an important role in routine patient management.     

Cross-resistance of drug-resistant murine leukemias to deoxyspergualin (NSC 356894) in vivo

Deoxyspergualin, the 15-deoxy derivative of the antibiotic spergualin, is a novel guanidino analog structurally related to spermine. Deoxyspergualin has significant activity in selected experimental tumor models, and clinical trials have been initiated. Described here are in vivo evaluations of the therapeutic activity of deoxyspergualin against murine leukemia lines specifically resistant to eight clinically useful antitumor drugs. These were P388 lines resistant to doxorubicin, vincristine, L-phenylalanine mustard, cisplatin, ara-C, and methotrexate and L1210 lines resistant to 5-FU, L-phenylalanine mustard, and cyclophosphamide. Sensitivity to deoxyspergualin was evaluated in parallel comparisons of each resistant leukemia to the sensitive line from which it had been derived. All experiments were repeated at least once for confirmation of results. Responses were quantitated in terms of the change in tumor cell numbers from the beginning of treatment to the end of treatment as estimated from the median survival times of dying mice. The results indicated that P388 leukemia resistant to cisplatin (P388/DDPt) was cross-resistant to deoxyspergualin. No cross-resistance was observed in leukemias resistant to doxorubicin, vincristine, ara-C, methotrexate, or cyclophosphamide. L1210 resistant to 5-FU (L1210/5-FU) was collaterally sensitive to deoxyspergualin. Although cross-resistance was also observed in P388/L-PAM, L1210/L-PAM retained sensitivity to deoxyspergualin. Total glutathione concentrations in P388/L-PAM and L1210/L-PAM provided no apparent explanation for this unexpected result. It may be tentatively concluded that resistance to cisplatin, L-PAM, or other DNA alkylators or cross-linkers may increase the potential for cross-resistance to deoxyspergualin. This conclusion requires verification with additional alkylating agents, with drug-resistant human tumor cell lines, and with prospective clinical studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of imatinib mesylate (Glivec) on human tumor-derived cells

Imatinib mesylate is a specific inhibitor of the Bcr-Abl protein tyrosine kinase that competes with ATP for its specific binding site in the kinase domain. It has activity against platelet-derived growth factor receptor alpha and beta (PDGFR-alpha and -beta), and c-kit, the receptor for stem cell factor. We have used a standardized ATP-tumor chemosensitivity assay and immunohistochemistry to determine the cytotoxicity of imatinib mesylate in tumor-derived cells from cutaneous and uveal melanoma, and ovarian carcinoma. Imatinib mesylate was tested at concentrations ranging from 2.0 to 0.0625 micromol/l alone and in combination with a cytotoxic drug (cisplatin, doxorubicin, paclitaxel or treosulfan). Imatinib mesylate showed low inhibition (IndexSUM>300) across the range of concentrations tested in this study, with few tumors exhibiting increasing inhibition with increased drug concentration. The median IC90 values for cutaneous and uveal melanoma and ovarian carcinoma were 13.2 micromol/l (4.0-294.3 micromol/l), 12.0 micromol/l (2.0-285.4 micromol/l) and 7.71 micromol/l (6.51-11.02 micromol/l), respectively. Imatinib mesylate potentiated the effect of different cytotoxics in 9% (5/54) of cases and had a negative effect in 13% (7/54) of cases, with no effect in the remainder. No correlation of effect was noted with c-kit, platelet-derived growth factor receptor-alpha or platelet-derived growth factor receptor-beta expression, assessed by immunohistochemistry. The signaling pathways mediated by activation of c-kit or platelet-derived growth factor receptor may act as antiapoptotic survival signals in some cancers and inhibition of these pathways may potentiate the activity of some cytotoxic drugs by inhibiting the survival signal. Growth inhibition, however, may reduce the efficacy of cytotoxic drugs, which tend to target proliferating cells preferentially, and clinical effects are therefore difficult to predict.     

Docetaxel in squamous cell cancer of the head and neck

Single-agent docetaxel induces a response in 21-42% of patients with recurrent squamous cell cancer of the head and neck (SCCHN). When used in combination with 5-fluorouracil (5-FU), response rates (RRs) of between 24 and 27% have been reported. In contrast, in combination with cisplatin, docetaxel has achieved a RR of 33% in previously treated patients and 86% in a subgroup of chemotherapy-naive advanced stage patients. The docetaxel/cisplatin combination appears to be highly active. High-dose induction chemotherapy for patients with locally advanced but potentially curable SCCHN is producing promising results: following combination therapy involving docetaxel, cisplatin, 5-FU and leucovorin (TPFL), RR are high and 75% of patients are alive at 2 years. Intermediate-dose induction chemotherapy involving docetaxel is also promising: the TAX 708 trial found an excellent 93% RR in 41 evaluable patients treated with docetaxel plus cisplatin and 5-FU (TPF). The rate of pathological complete response was also high. The toxicities with TPF therapy were similar to those seen with cisplatin/5-FU regimens without docetaxel. A phase III trial of this approach is currently being conducted.     

Available options in chemotherapy for advanced gastric cancer: the current developments in Japan

Although techniques for early diagnosis and treatment of gastric cancer have been established, standard treatment for advanced gastric cancer has not. 5-Flourouracil (5-FU) plus cisplatin containing regimens, including 5-FU plus cisplatin, epirubicin plus cisplatin and 5-FU, and docetaxel plus cisplatin and 5-FU, are considered to be the most effective regimens for advanced gastric cancer in US, Europe and Korea. In Japan, oral fluoropyrimidine S-1 is currently considered to be the first-line treatment for advanced gastric cancer. S-1-based combination therapies with other promising drugs, including cis-platin, irinotecan and taxanes, are expected to yield good results. Above all, S-1 plus cisplatin therapy showed high efficacy and expected to be a standard therapy for advanced gastric cancer. Further evaluation by well-controlled clinical trials is still required.     

Anti-tumor activity of heptaplatin in combination with 5-fluorouracil or paclitaxel against human head and neck cancer cells in vitro

Heptaplatin (HTP), a newly developed platinum analog, has been approved for the treatment of gastric cancers in South Korea. In this study we explored the potential of HTP for the treatment of head and neck squamous cell cancers (HNSCC). The anti-proliferative activity of HTP was evaluated in FaDu, a human HNSCC cell line. Combinations of HTP with 5-fluorouracil (5-FU) or paclitaxel (PTX) were determined using combination indexes, and were compared with combinations of cisplatin and 5-FU or PTX. In order to evaluate the transport of HTP into tumor tissue, its penetration through multicell layers (MCLs) of cancer cells was measured. Cisplatin+5-FU and HTP+5-FU showed additive to antagonistic interactions. In terms of the HTP+paclitaxel combination, HTP showed antagonism and additivity at the 50 and 80% growth inhibition levels, respectively. An additive interaction was obtained and apoptosis was increased by 2-fold at both inhibition levels when the combinatorial PTX dose was reduced to 1/10. HTP, but not cisplatin or oxaliplatin (L-OHP), maintained its anti-proliferative activity after MCL penetration at clinically relevant concentrations, which can be attributed to lower protein binding of HTP. In conclusion, the present study suggests that low-dose PTX may sensitize tumor cells to HTP. HTP also showed greater penetration through multilayers of tumor cells compared to cisplatin and L-OHP, which may be an important characteristic for solid tumor treatment. Overall, the present study supports the clinical development of HTP in combination with low-dose PTX against HNSCC.     

Evaluation of the mTOR inhibitor, everolimus, in combination with cytotoxic antitumor agents using human tumor models in vitro and in vivo

The aim was to determine the potential of the allosteric mammalian target of rapamycin inhibitor, everolimus, to act in combination with cytotoxic anticancer compounds in vitro and in vivo. A concomitant combination in vitro showed no evidence of antagonism, but enhanced the antiproliferative effects (additive to synergistic) with cisplatin, doxorubicin, 5-fluorouracil, gemcitabine, paclitaxel, and patupilone. Everolimus (1-5 mg/kg/d orally) was evaluated for antitumor activity in vivo alone or in combination with suboptimal cytotoxic doses using athymic nude mice bearing subcutaneous human H-596 lung, KB-31 cervical, or HCT-116 colon tumor xenografts. Everolimus monotherapy was very well tolerated and caused inhibition of tumor growth, rather than regression, and this was associated with a dose-dependent decline in tumor pS6 levels, a key downstream protein of mammalian target of rapamycin. At the doses used, the cytotoxics inhibited tumor growth and caused tolerable body-weight loss. Concomitant combinations of cisplatin, doxorubicin, paclitaxel, or patupilone with everolimus produced cooperative antitumor effects, in some cases producing regressions without clinically significant increases in toxicity. In contrast, combinations with gemcitabine and 5-fluorouracil were less well tolerated. Alternative administration schedules were tested for cisplatin, gemcitabine, or paclitaxel combined with everolimus: these did not dramatically affect cisplatin or gemcitabine activity or tolerability but were antagonistic for paclitaxel. Everolimus showed promising maintenance activity after treatment with doxorubicin or paclitaxel ceased. Overall, the results confirm that everolimus is an effective, well-tolerated suppressor of experimental human tumor growth, and although it did not show strong potentiation of efficacy, antitumor activity in vivo was increased without marked increases in toxicity, supporting clinical use of everolimus as a partner for conventional cytotoxics.     

Hematological side-effect profiles of individualized chemotherapy regimen for recurrent ovarian cancer

The long-term results for patients with recurrent ovarian cancer (ROC) are poor. There is a need to optimize treatment strategies to improve outcome by avoiding ineffective regimens which are often associated with exacerbated side-effects. Individualized chemotherapy regimens guided by a chemosensitivity assay (ATP-tumor chemosensitivity assay) have already been used successfully to direct chemotherapy. Taking the results of this assay into account, application of drug combinations appears more advisable. Here we present a systematic evaluation of toxicities seen with individualized chemotherapy for ROC. A total of 62 patients who received 314 cycles of antineoplastic therapies were evaluated. Three single agents (topotecan, paclitaxel and gemcitabine) and five combinations (cisplatin/gemcitabine, carbopatin/gemcitabine, gemcitabine/treosulfan, mitoxantrone/paclitaxel and carboplatin/paclitaxel) were examined. With respect to myelotoxicity, most single agents except topotecan revealed favorable results in comparison to drug combinations. However, this observation lacks statistical significance. Generally, severe myelosuppression was rare. The highest incidence of leukopenia was seen in regimens with mitoxantrone/paclitaxel or gemcitabine/treosulfan, respectively. Thrombocytopenia accompanied most commonly a topotecan therapy. In the present study combination regimens tend to be more toxic than monotherapies. When response rates are comparable, empirically chosen treatment combination therapies should only be practiced in carefully planned clinical studies.     

奥沙利铂联合氟尿嘧啶和亚叶酸钙治疗铂耐药复发卵巢癌初探

目的探讨奥沙利铂(L-OHP)联合氟尿嘧啶(5-FU)和亚叶酸钙(LV)治疗晚期复发性卵巢癌的临床效果。方法对6例铂耐药复发卵巢癌患者行L-OHP联合5-FU、LV方案化疗,每3周重复,观察其临床效果及毒副反应。结果疗效评定4例部分有效(PR),1例稳定(SD),1例进展(PD),毒副反应均不严重。结论奥沙利铂联合5-FU、LV治疗铂耐药复发卵巢癌有一定疗效,值得进一步研究。     

Enhancement of the anti-tumor activity of S-1 by low-dose cisplatin in mice bearing the sarcoma-180 model

The combination of S-1, consisting of 1 mol/l tegafur, 0.4 mol/l 5-chloro-2,4-dihydroxypyridine and 1 mol/l potassium oxonate, plus low-dose cisplatin has showed promising anti-tumor activities in experimental and clinical studies. The aim of this study was to investigate the mechanism of this combination chemotherapy. Mice bearing sarcoma-180 cells were divided into groups of seven animals each - Group A: no treatment; Group B: 5-fluorouracil (5-FU) 10 mg/kg continuous i.p. infusion; Group C: S-1 10 mg/kg p.o.; Group D: cisplatin 0.2 mg/kg i.p.; Group E: B+D; Group F: C+D. Treatments were given for 5 consecutive days, and then anti-tumor activity, the concentration of 5-FU, the thymidylate synthase inhibition rate (TSIR) and the level of 5-FU incorporated into RNA (F-RNA) in tumor tissue were evaluated. Anti-tumor activity in Group F was higher than in any other group. A significantly higher concentration of 5-FU in tumor was detected in the S-1-treated groups (C and F) than in the 5-FU-treated groups (B and E). No differences in TSIR were observed between the groups treated with 5-FU or S-1 with or without cisplatin; however, the F-RNA level in Group F was about 1.24 times significantly higher than that in Group C. Group F showed the highest anti-tumor activity, with increasing intratumoral levels of 5-FU and F-RNA, but not that of TSIR. These results suggested that the superior anti-tumor activity obtained by S-1+cisplatin might be associated with an incorporation of 5-FU into RNA.     

Development of Stealth Liposome Formulation of 2′-Deoxyinosine as 5-Fluorouracil Modulator: <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis> Study

Purpose The aims of this study were to develop a stealth, pegylated liposomal formulation of 2′-deoxyinosine (d-Ino), a 5-fluorouracil (5-FU) modulator, to evaluate its efficacy in vitro and in tumor-bearing mice, and to study its pharmacokinetics in rats. Method After designing a pegylated liposome encapsulating d-Ino (L-d-Ino), we evaluated its efficacy as 5-FU modulator in vitro. Antiproliferative assays, thymidylate synthase (TS) inhibition, and apoptosis studies were carried out to check whether an optimization of 5-FU action was achieved on the 5-FU-resistant SW620 cell line. Animal pharmacokinetic and ex vivo studies were next performed to confirm that L-d-Ino displayed a slower plasma elimination pattern than free d-Ino. Finally, effects on tumor growth of L-d-Ino + 5-FU combination was evaluated in xenografted mice. Results We developed a stable, sterile, and homogenous 100-nm population of pegylated liposomes encapsulating 30% of d-Ino. Liposomal d-Ino exhibited a strong potential as 5-FU modulator in vitro by enhancing TS inhibition and subsequent apoptosis induction, while displaying a better pharmacokinetic profile in animals, with a near seven times clearance reduction as compared with the free form. When used in tumor-bearing mice in combination with 5-FU, our results showed next that the association led to 70% of tumor reduction with a doubling median survival time as compared with untreated animals, whereas 5-FU alone was ineffective. Conclusion Our data show that liposomal d-Ino, through an optimized pharmacokinetic profile, displays apotenteffect as fluoropyrimidines modulator, both in vitro and in xenografted mice. Besides, we showed here that itispossible to reverse a resistant phenotype to 5-FU, a major drug extensively described in clinical oncology.     

Pharmacokinetics of paclitaxel and cisplatin in a hemodialysis patient with recurrent ovarian cancer

This is the first report that the combination of paclitaxel and cisplatin is feasible in a patient with recurrent ovarian cancer undergoing hemodialysis. Paclitaxel at a dose of 150 mg/m(2) was administered as a 3-h continuous i.v. infusion. Thirty minutes after paclitaxel administration, cisplatin was administered at a dose of 30 mg/m(2) for 30 min. Hemodialysis was started 30 min after completion of the cisplatin infusion and performed for 5 h. The maximum plasma concentrations of paclitaxel, total platinum and free platinum were 3.26, 2.44 and 1.84 microg/ml, respectively. The AUC of paclitaxel and free platinum were 15.3 and 1.76 microg x h/ml, respectively. The pelvic tumor size was reduced by 42% on MRI after the second course of this therapy. Grade IV neutropenia and grade III thrombopenia were observed. We conclude that paclitaxel and cisplatin combination chemotherapy is efficacious and feasible for an ovarian cancer patient under hemodialysis.     

Trastuzumab and Liposomal Doxorubicin in the Treatment of MCF-7 Xenograft Tumor-Bearing Mice: Combination Does Not Affect Drug Serum Levels

Purpose We assessed the combination of doxorubicin or liposomal doxorubicin with trastuzumab for alterations in peak serum drug levels, as these agents are increasingly being paired in the treatment of aggressive breast cancer. We hypothesized that trastuzumab would exhibit a slower rate of elimination from the serum when in combination with liposomal doxorubicin based on the known effects of liposomal doxorubicin on phagocytic cells of the mononuclear phagocyte system (MPS), which are responsible in part for the uptake and degradation of antibodies.Methods Doxorubicin and trastuzumab serum levels were assessed following injection of free doxorubicin, liposomal doxorubicin, or trastuzumab into female RAG2-M mice bearing subcutaneous MCF-7^HER-2 tumors. The effects of combination drug treatment on tumor growth were compared to single-agent treatment.Results Peak serum trastuzumab levels were not altered as a result of addition of doxorubicin therapy, nor were doxorubicin levels altered over 24 h as a result of coadministration of trastuzumab. Liposomal doxorubicin administration did result in serum doxorubicin levels 200- to 1000-fold higher than with injection of free doxorubicin.Conclusions For the specific combination of trastuzumab with doxorubicin, either in free or liposomal form, coadministered in mice, there was no impact of one drug on the other in terms of peak serum drug levels or efficacy.