Gemcitabine increases systemic 5-fluorouracil exposure in advanced cancer patients

Anti-Neoplastic Cytotoxicity of Gemcitabine-(C4-amide)-[anti-EGFR] in Dual-combination with Epirubicin-(C3-amide)-[anti-HER2/neu] against Chemotherapeutic-Resistant Mammary Adenocarcinoma (SKBr-3) and the Complementary Effect of Mebendazole

AIMS

Delineate the feasibility of simultaneous, dual selective "targeted" chemotherapeutic delivery and determine if this molecular strategy can promote higher levels anti-neoplastic cytotoxicity than if only one covalent immunochemotherapeutic is selectively "targeted" for delivery at a single membrane associated receptor over-expressed by chemotherapeutic-resistant mammary adenocarcinoma.

METHODOLOGY

Gemcitabine and epirubicin were covalently bond to anti-EGFR and anti-HER2/neu utilizing a rapid multi-phase synthetic organic chemistry reaction scheme. Determination that 96% or greater gemcitabine or epirubicin content was covalently bond to immunoglobulin fractions following size separation by micro-scale column chromatography was established by methanol precipitation analysis. Residual binding-avidity of gemcitabine-(C4-amide)-[anti-EG-FR] applied in dual-combination with epirubicin-(C3-amide)-[anti-HER2/neu] was determined by cell-ELIZA utilizing chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) populations. Lack of fragmentation or polymerization was validated by SDS-PAGE/immunodetection/chemiluminescent autoradiography. Anti-neoplastic cytotoxic potency was determined by vitality stain analysis of chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) monolayers known to uniquely over-express EGFR (2 × 105/cell) and HER2/neu (1 × 106/cell) receptor complexes. The covalent immunochemotherapeutics gemcitabine-(C4-amide)-[anti-EGFR] and epirubicin-(C3-amide)-[anti-HER2/neu] were applied simultaneously in dual-combination to determine their capacity to collectively evoke elevated levels of anti-neoplastic cytotoxicity. Lastly, the tubulin/microtubule inhibitor mebendazole evaluated to determine if it's potential to complemented the anti-neoplastic cytotoxic properties of gemcitabine-(C4-amide)-[anti-EGFR] in dual-combination with epirubicin-(C3-amide)-[anti-HER2/neu].

RESULTS

Dual-combination of gemcitabine-(C4-amide)-[anti-EGFR] with epirubicin-(C3-amide)-[anti-HER2/neu] produced greater levels of anti-neoplastic cytotoxicity than either of the covalent immunochemotherapeutics alone. The benzimidazole microtubule/tubulin inhibitor, mebendazole complemented the anti-neoplastic cytotoxicity of gemcitabine-(C4-amide)-[anti-EGFR] in dual-combination with epirubicin-(C3-amide)-[anti-HER2/neu].

CONCLUSIONS

The dual-combination of gemcitabine-(C4-amide)-[anti-EGFR] with epirubicin-(C3-amide)-[anti-HER2/neu] produced higher levels of selectively "targeted" anti-neoplastic cytotoxicity against chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) than either covalent immunochemotherapeutic alone. The benzimidazole tubulin/microtubule inhibitor, mebendazole also possessed anti-neoplastic cytotoxicity against chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) and complemented the potency and efficacy of gemcitabine-(C4-amide)-[anti-EGFR] in dual-combination with epirubicin-(C3-amide)-[anti-HER2/neu].

Prospective phase II trial of a combination of gemcitabine and UFT as first-line treatment in elderly patients with advanced non-small cell lung cancer

BACKGROUND

The standard regimen in elderly patients with non-small-cell lung cancer (NSCLC) is still uncertain. Gemcitabine is one of the most widely used drugs for the treatment of NSCLC, and several phase II trials specifically designed for elderly patients with advanced NSCLC have confirmed the role of gemcitabine in this setting. In addition, oral uracil-tegafur (UFT) was associated with a survival advantage in the adjuvant setting. Therefore, we performed a phase II study using the combination of gemcitabine and UFT as first-line therapy in elderly patients with advanced NSCLC.

METHODS

Chemotherapy-naïve, elderly (≥ 70 years) patients who had histologically or cytologically confirmed with stage IIIB or IV NSCLC with a performance status of 1-2 were enrolled. Patients received gemcitabine (1250 mg/m(2) on days 1 and 8, respectively) and UFT (400mg/day on days 1-14) every 3 weeks for up to four cycles. Patients who had not progressed after four cycles continued UFT monotherapy until progression. Primary endpoint was overall response rate and secondary endpoints were overall survival, time to progression and safety profiles.

RESULTS

Between March 2008 and November 2010, 48 patients were enrolled. The median age was 74.5 years (range: 70-84 years), and there were 29 males. The performance status was 1 in 41 and 2 in 7 patients. Thirty-one (64.6%) patients were stage IV and seventeen (35.4%) patients were stage IIIB. Thirty patients (62.5%) completed four cycles of chemotherapy. Response was evaluated in 44 patients. Partial response was achieved in twelve (25.0%) patients and stable disease in 23 (47.9%) patients. Disease control rate was 72.9%. The median survival time was 6.1 months (95% confidence interval [CI]; 5.1-7.0 months), the 1-year survival rate was 29.1% and the median time to progression was 4.6 months (95% CI; 3.7-5.5 months). Toxicities were mild and mostly hematological adverse events. Grade 3/4 neutropenia occurred in 8.3% of patients and one patients experienced febrile neutropenia. Grade 3/4 anemia and thrombocytopenia occurred in 2.1% and 2.1% of patients, respectively. Non-hematological toxicities were tolerable.

CONCLUSIONS

The combination of gemcitabine and UFT was effective in disease control and well tolerated first-line regimen in elderly patients with advanced NSCLC.

Dose-finding study and pharmacogenomic analysis of fixed-rate infusion of gemcitabine, irinotecan and bevacizumab in pretreated metastatic colorectal cancer patients

BACKGROUND

To determine the dose-limiting toxicity (DLT), maximum tolerated dose, recommended dose (RD) and preliminary evidence of activity of escalating doses of irinotecan (CPT-11) fixed-dose-rate infusional gemcitabine (FDR-GMB) and bevacizumab in pretreated metastatic colorectal cancer (mCRC) patients. Pharmacogenomic analysis was performed to investigate the association between VEGF single-nucleotide polymorphisms and clinical outcome.

PATIENTS AND METHODS

A total of 89 mCRC patients were recruited in a two-step study design; 28 were included in the dose-finding study and 59 in the pharmacogenomic analysis. The FDR-GMB of 1000 mg m⁻², bevacizumab 5 mg kg⁻¹ and CPT-11 doses ranging from 100 to 160 mg m⁻² were explored. The VEGF protein serum levels were quantified by EIA. Allelic discrimination was performed to genotype polymorphisms in the VEGF gene.

RESULTS

CPT-11 RD was 150 mg m⁻². Diarrhoea and neutropenia were the DLT. After a median follow-up of 42 months, the median time to progression (TTP) and overall survival were 5.2 and 19.9 months, respectively. VEGF levels were significantly correlated with VEGF-2578AA and VEGF-460CC genotypes, and a trend was observed with VEGF+405GG genotype. The presence of any of these genotypes correlated with a longer median TTP (8.8 vs 4.5 months, P=0.04).

CONCLUSION

The triplet combination tested in this study is effective and well tolerated. A possible predictive role for VEGF gene polymorphisms and baseline VEGF circulating levels is suggested.

Is there a palliative benefit of gemcitabine plus fluoropyrimidines in patients with refractory colorectal cancer? A review of the literature previously presented: poster at the 2008 Gastrointestinal Cancer Symposium (Abstract No. 512)

INTRODUCTION

Fluoropyrimidines with oxaliplatin or irinotecan plus bevacizumab is the standard chemotherapy combination in patients with advanced colorectal cancer (CRC). Gemcitabine acts synergistically with fluoropyrimidines to enhance the binding of thymidylate synthase and increase inhibition of DNA synthesis. The objective of this review is to evaluate the literature for evidence of efficacy and safety of fluoropyrimidine plus gemcitabine (FG) in patients with advanced CRC.

METHODS

Relevant studies were identified in PubMed, Ovid, Cochrane database and the American Society of Clinical Oncology abstracts using the following search terms: gemcitabine, fluorouracil, capecitabine and colorectal cancer. Only studies using the FG combination were selected.

RESULTS

Forty-two advanced CRC patients were evaluated in two Phase I studies and the maximum tolerated dose of gemcitabine was 900 - 1,000 mg/m(2) weekly with either bolus 5-fluorouracil (5-FU) or capecitabine. A total of 216 advanced CRC patients were evaluated in six Phase II studies. Gemcitabine (750 - 1,250 mg/m2) with either 5-FU (continuous infusion or bolus) or capecitabine was administered as first-line therapy in two studies and as third-line therapy in three studies. The range reported for overall response rate was 30 - 38.3%, median time to progression was 4 - 8.3+ months and median survival was 9.8 - 18+ months. The most commonly reported grade 3 - 4 toxicities were neutropenia, thrombocytopenia and mucositis.

CONCLUSIONS

Fluoropyrimidine plus gemcitabine is clinically active in patients with refractory CRC demonstrating prolonged median time to progression and acceptable toxicity only when bolus 5-FU was not used. Studies are underway to evaluate the combinations of FG with other chemotherapy or targeted agents. Meanwhile, FG may be considered for patients with advanced CRC who are refractory to primary treatment without other options or who are not eligible for clinical studies.

Plasma pharmacokinetics after combined therapy of gemcitabine and oral S-1 for unresectable pancreatic cancer

Background

The combination of gemcitabine (GEM) and S-1, an oral 5-fluorouracil (5-FU) derivative, has been shown to be a promising regimen for patients with unresectable pancreatic cancer.

Methods

Six patients with advanced pancreatic cancer were enrolled in this pharmacokinetics (PK) study. These patients were treated by oral administration of S-1 30 mg/m² twice daily for 28 consecutive days, followed by a 14-day rest period and intravenous administration of GEM 800 mg/m² on days 1, 15 and 29 of each course. The PK parameters of GEM and/or 5-FU after GEM single-administration, S-1 single-administration, and co-administration of GEM with pre-administration of S-1 at 2-h intervals were analyzed.

Results

The maximum concentration (Cmax), the area under the curve from the drug administration to the infinite time (AUCinf), and the elimination half-life (T1/2) of GEM were not significantly different between GEM administration with and without S-1. The Cmax, AUCinf, T1/2, and the time required to reach Cmax (Tmax) were not significantly different between S-1 administration with and without GEM.

Conclusion

There were no interactions between GEM and S-1 regarding plasma PK of GEM and 5-FU.

Imexon-based combination chemotherapy in A375 human melanoma and RPMI 8226 human myeloma cell lines

PURPOSE

This study evaluated the cytotoxic effects of imexon (NSC-714597) in tumor cells when combined with a broad panel of chemotherapeutic drugs.

METHODS

The sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assays were used to analyze the degree of growth inhibition for the combination studies in the A375 human malignant melanoma and RPMI 8226 human multiple myeloma cell lines, respectively. Cells were continuously exposed to both drugs at a constant molar ratio for 4-5 days. Combination effects were analyzed using the Median Effect method. Statistical significance was inferred if the 95% confidence interval for the combination interaction (C.I.) values for a particular two-drug combination did not include 1.0 (additivity). Synergy was inferred for C.I. values<1.0 and antagonism for CI values>1.0.

RESULTS

Imexon was synergistic when combined with DNA-binding agents (cisplatin, dacarbazine, melphalan) and pyrimidine-based antimetabolites (cytarabine, fluorouracil, gemcitabine) in both cell lines. Antagonistic combinations with imexon included methotrexate and the topoisomerase I (TOPO I) and II (TOPO II) inhibitors irinotecan, doxorubicin, mitoxantrone and etoposide. Docetaxel was synergistic with imexon in both cell lines whereas paclitaxel and fludarabine showed a mixed result. Dexamethasone and the proteasome inhibitor bortezomib showed synergy in myeloma cells and additivity in the melanoma cells. The vinca alkaloid, vinorelbine, and the multi-targeted antifol, pemetrexed, were additive with imexon in both cell lines.

DISCUSSION

The consistent synergy seen for imexon and alkylating agents may relate to the sulfhydryl-lowering effect of imexon, which would render cells more sensitive to electrophilic species from the alkylators. The marked synergy noted with pyrimidine-based antimetabolites was unexpected and may relate to the induction of cell cycle arrest in S-phase. The strong antagonism noted for imexon with topoisomerase I and II inhibitors may be due to the effect of imexon at increasing oxidant levels which are known to antagonize the cytotoxic effects of topoisomerase poisons. In contrast, the synergy seen with bortezomib in myeloma cells may be related to an increase in reactive oxygen species (ROS) from both drugs. These results suggest that combinations of imexon with alkylating agents and pyrimidine-based antimetabolites are rational to pursue in therapeutic studies in vivo.

Schedule-dependent therapeutic effects of gemcitabine combined with uracil-tegafur in a human pancreatic cancer xenograft model

OBJECTIVES

Gemcitabine is taken up by cells mainly via human equilibrative nucleoside transporter 1 (hENT1). Pretreatment of cancer cell lines with 5-fluorouracil (5-FU) leads to an increase in the expression of hENT1 and augments the effect of single-agent gemcitabine treatment in vitro. The purpose of the present study was to evaluate the relationship between the schedules of gemcitabine/uracil-tegafur (UFT) combination therapy and their effects in pancreatic cancer in vivo.

METHODS

The expression level of hENT1 mRNA was examined using 6 types of human pancreatic cancer cell lines treated with 5-FU and MiaPaCa-2 xenograft tumors in BALB/c nu/nu mice treated with UFT. A [H] gemcitabine cellular uptake assay was performed using MiaPaCa-2 cells treated with 5-FU. We compared the effects of 6 different schedules of treatment using UFT and/or gemcitabine on MiaPaCa-2 xenograft tumors.

RESULTS

MiaPaCa-2 cell line was one of the lines that showed the highest rate of 5-FU-induced increase in the hENT1 mRNA level. Gemcitabine uptake was significantly increased when cells were treated with 5-FU. Treatment with UFT significantly increased the hENT1 mRNA expression in MiaPaCa-2 tumors. A significant growth inhibition of MiaPaCa-2 tumors was observed in the mice treated with UFT followed by gemcitabine as compared with either untreated mice or UFT alone-treated mice.

CONCLUSIONS

Our results suggest that the schedule in which the gemcitabine is administered after UFT may be the optimal combination for gemcitabine/UFT treatment in pancreatic cancer.

Dendritic cell-mediated cross-presentation of antigens derived from colon carcinoma cells exposed to a highly cytotoxic multidrug regimen with gemcitabine, oxaliplatin, 5-fluorouracil, and leucovorin, elicits a powerful human antigen-specific CTL response with antitumor activity in vitro

Gemcitabine, oxaliplatin, leucovorin, and 5-fluorouracil (GOLF) is a novel multidrug regimen inducing high levels of necrosis and apoptosis in colon carcinoma cells. This regimen is also able to promote a process of Ag remodeling including up-regulation of immunotherapy targets like carcinoembryonic Ag (CEA), thymidylate synthase (TS). We have conducted a preclinical study aimed to investigate whether these drug-induced modifications would also enhance colon cancer cell immunogenicity. Several CTL lines were thus generated by in vitro stimulating human HLA-A(*)02.01(+) PBMCs, from normal donors and colon cancer patients, with autologous dendritic cells cross-primed with cell lysates of colon cancer cells untreated, irradiated, or previously exposed to different drug treatments including the GOLF regimen. Class I HLA-restricted cytolytic activity of these CTL lines was tested against colon cancer cells and CEA and TS gene transfected target cells. These experiments revealed that CTLs sensitized with GOLF-treated cancer cells were much more effective than those sensitized with the untreated colon carcinoma cells or those exposed to the other treatments. CTL lines sensitized against the GOLF-treated colon cancer cells, also expressed a greater percentage of T-lymphocyte precursors able to recognize TS- and CEA-derived peptides. These results suggest that GOLF regimen is a powerful antitumor and immunomodulating regimen that can make the tumor cells a suitable means to induce an Ag-specific CTL response. These results suggest that a rationale combination of GOLF chemotherapy with cytokine-based immunotherapy could generate a chemotherapy-modulated Ag-specific T-lymphocyte response in cancer patients able to destroy the residual disease survived to the cytotoxic drugs.

Gemcitabine (GEM) plus oxaliplatin, folinic acid, and 5-fluorouracil (FOLFOX-4) in patients with advanced gastric cancer

BACKGROUND AND AIMS

oxaliplatin in combination with folinic acid (FA) and infusional 5-fluorouracil (5-FU) has shown significant anti-tumor activity in gastric cancer patients (FOLFOX). Previous studies have shown that gemcitabine (GEM), a new fluorinated anti-metabolite, enhances the individual anti-tumor activity of either 5-FU or oxaliplatin. We have therefore designed a multi-center phase II trial in order to test a novel GEM+FOLFOX-4 regimen in patients with metastatic gastric cancer.

METHODS

we enrolled 36 patients, 28 males and 8 females, with an average age of 64.4 years (range 37-78), who received bi-weekly treatment with GEM (1,000 mg/m2 on day 1), levo-FA (100 mg/m2 on days 1 and 2), a 5-FU (400 mg/m2) bolus injection followed by 22-h continuous infusion (800 mg/m2) on days 1 and 2, and oxaliplatin 85 mg/m2 in a 4-6 h intravenous (i.v.) infusion before the second FUFA administration on day 2.

RESULTS

the most frequent side effect was grade 1-2 hematological toxicity and late sensorial neurotoxicity. Two patients developed hypersensitivity to oxaliplatin while another developed an aseptic eosinophilic pneumonitis. Two patients refused to continue the treatment after two cycles of chemotherapy and were lost at the follow-up. Among the remaining 34 patients four achieved a complete response, 15 a partial response, 12 had a stable disease and three progressed.

CONCLUSIONS

these results may grant the rationale to evaluate this multi-drug combination in randomized phase III trials in advanced gastric cancer.

A phase II study of raltitrexed and gemcitabine in patients with advanced pancreatic carcinoma

Advanced adenocarcinoma of the pancreas has a very poor prognosis. The aim of this study was to assess the efficacy and tolerability of a combination of the chemotherapeutic agents gemcitabine and raltitrexed. Chemonaïve patients with advanced adenocarcinoma of the pancreas were treated with a combination of raltitrexed (3.5 mg m⁻² on day 1 of a 21-day treatment cycle) and gemcitabine (800 mg m⁻² intravenously (i.v.) on days 1 and 8 of a 21-day cycle). Between April 2000 and February 2003, 27 patients were enrolled onto the study. The mean duration of treatment was 11 weeks. Four of 27 patients experienced at least one episode of grade 3 or 4 neutropenia. One patient with grade 4 neutropenia died due to sepsis. Four of 27 patients experienced grade 4 diarrhoea. There was one partial remission (4%) and 12 patients experienced disease stabilisation (44%). The 6-month and 1-year survival rates were 37 and 11%, respectively. Symptomatic benefit occurred in seven (26%) patients. We conclude that a combination of raltitrexed and gemcitabine, using the schedule and doses in this study, cannot be recommended for patients with advanced pancreatic cancer.

A novel biweekly multidrug regimen of gemcitabine, oxaliplatin, 5-fluorouracil (5-FU), and folinic acid (FA) in pretreated patients with advanced colorectal carcinoma

Previous results suggest that GEM affects 5-fluorouracil (5-FU) metabolism and pharmacokinetics in cancer patients, while combined with oxaliplatin, levo-folinic acid, and 5-FU (GOLF regimen), at doses achievable in cancer patients, determines high cytotoxic and proapoptotic antitumour activity in colon cancer cells in vitro. On these bases we designed a phase I-II clinical trial testing the GOLF regimen in patients with metastatic colorectal carcinoma, who had received at least a prior line of chemotherapy. In total, 29 patients (20 males and nine females) enrolled in the study received every 2 weeks, gemcitabine (patients #1-3 received 600 mg m(-2); patients # 4-6 received 850 mg m(-2); while patients # 7-29 received 1000 mg m(-2)) on the day 1, levo-folinic acid (100 mg m(-2)) on the days 1 and 2; 5-fluorouracil (400 mg m(-2)) in bolus injection, followed by a 22-h continuous infusion (800 mg m(-2)) on the days 1 and 2, and oxaliplatin (85 mg m(-2)), 6 h after the 5-FU bolus on day 2. The most frequent side effect was grade I-II haematological toxicity. In total, 28 patients were evaluable for response: three achieved a complete response, nine a partial response, 10 had a stable disease, and six progressed. The average time to progression and overall survival of the patients was, respectively, 7.26 and 22 months. Our GOLF combination is well tolerated and seems promising for the treatment of advanced colorectal cancer.

A novel biweekly pancreatic cancer treatment schedule with gemcitabine, 5-fluorouracil and folinic acid

Pancreatic adenocarcinoma is a common disease considered to be poorly responsive to antiblastic treatment. Recent clinical and preclinical results suggest that a combined treatment of gemcitabine (GEM), 5-flurouracil (5-FU) and folinic acid (FA) offers a clinical benefit in patients with advanced pancreas adenocarcinoma. The aim of this phase II clinical trial was to evaluate the antitumour activity and toxicity of a novel biweekly schedule of this combination in patients with pancreatic adenocarcinoma. A total of 42 patients received a 30 min infusion of FA (100 mg m(-2)) and 5-FU (400 mg m(-2)) (FUFA) on days 1-3, and GEM 1000 mg m(-2) on day 1 every 15 days. We observed 13 objective responses (two complete, 11 partial) and 23 stable diseases. The median time to progression was 9.75 months (95% Confidence Interval (CI), 6.88-12.62) and the median overall survival was 13.10 months (95% CI 9.64-16.56). There were seven cases of each grade III gastroenteric and haematological toxicity. The GEM plus FUFA combination appears to be well tolerated and very active in patients with pancreatic carcinoma.