Ternary combination of irinotecan, fluorouracil-folinic acid and oxaliplatin: results on human colon cancer cell lines

Radiosensitizing Effects of Irinotecan versus Oxaliplatin Alone and in Combination with 5-Fluorouracil on Human Colorectal Cancer Cells

To date, oxaliplatin and irinotecan are used in combination with 5-flourouracil (5-FU) for metastatic colorectal cancer. In this study it was tested whether oxaliplatin and irinotecan and their combinations with 5-FU have an enhanced effect when treated simultaneously with ionizing radiation. In addition, it should be compared whether one combination therapy is more effective than the other. Colorectal cancer cells (HT-29) were treated with irinotecan or oxaliplatin, both alone and in combination with 5-FU, and subsequently irradiated. The cell growth, metabolic activity and proliferation of cells were investigated, and the clonogenic survival was determined. Furthermore, the assessment of radiation-induced DNA damage and the influence of the drugs and their combinations on DNA damage repair was investigated. Treatment with irinotecan or oxaliplatin in combination with 5-FU inhibited proliferation and metabolic activity as well as clonogenic survival and the DNA damage repair capacity of the tumor cells. The comparison of oxaliplatin and irinotecan with simultaneous irradiation showed the same effect of both drugs. When oxaliplatin or irinotecan was combined with 5-FU, tumor cell survival was significantly lower than with monotherapy; however, there was no superiority of either combination regimen. Our results have shown that the combination of 5-FU and irinotecan is as effective as the combination of 5-FU with oxaliplatin. Therefore, our data support the use of FOLFIRI as a radiosensitizer.

A versatile gas-generator promoting drug release and oxygen replenishment for amplifying photodynamic-chemotherapy synergetic anti-tumor effects

Excellent efficiency of combinational therapy of chemotherapy and photodynamic therapy (PDT) highly depends on the amounts of drug and oxygen in tumor tissue. However, how to cleverly promote drug release accompanied with improving oxygen concentration remains a challenge. Herein, we proposed a gas-generator that realized a high drug loading and integrated facilitation of drug release with oxygen replenishment into a single and simple system, utilizing huge cavities and mesoporous channels of hollow mesoporous silica nanoparticles (HMSNs) for encapsulating oxygen (O₂) saturated perfluoropentane (PFP) droplets, indocyanine green (ICG) and doxorubicin (DOX), biocompatible polydopamine (PDA) as the gatekeepers. Under irradiation of 808 nm laser, the thermal effect of PDA caused PFP droplets occur liquid-gas phase transition that triggered the burst release of DOX and O₂, finally amplifying the synergetic effects of PDT and chemotherapy both in vitro and in vivo. The influence of PFP, GSH and laser on drug release kinetic was explored through mathematical models. Notably, the mechanism of gas-generator on accelerating drug release under irradiation based on doing volume work and enhancing diffusion coefficient was clarified by researching the relation between DOX release, PFP release and temperature change. Additionally, the way of replenishing O₂ did not rely on intracellular components but timely offered abundant "fuels" for producing reactive oxygen species (ROS) when compared with traditional manners. This work provides a new research strategy for boosting drug release and opens an avenue for constructing multifunctional controlled delivery systems.

Drug-Drug Interactions of Irinotecan, 5-Fluorouracil, Folinic Acid and Oxaliplatin and Its Activity in Colorectal Carcinoma Treatment

The combination of folinic acid, 5-fluorouracil, oxaliplatin and/or irinotecan (FOLFOXIRI) is the standard of care for metastatic colorectal cancer (CRC). This strategy inhibits tumor growth but provokes drug resistance and serious side effects. We aimed to improve FOLFOXIRI by optimization of the dosing and the sequence of drug administration. We employed an orthogonal array composite design and linear regression analysis to obtain cell line-specific drug combinations for four CRC cell lines (DLD1, SW620, HCT116, LS174T). Our results confirmed the synergy between folinic acid and 5-fluorouracil and additivity, or even antagonism, between the other drugs of the combination. The drug combination administered at clinical doses resulted in significantly higher antagonistic interactions compared to the low-dose optimized drug combination (ODC). We found that the concomitant administration of the optimized drug combination (ODC) was comparatively active to sequential administration. However, the administration of oxaliplatin or the active metabolite of irinotecan seemed to sensitize the cells to the combination of folinic acid and 5-fluorouracil. ODCs were similarly active in non-cancerous cells as compared to the clinically used doses, indicating a lack of reduction of side effects. Interestingly, ODCs were inactive in CRC cells chronically pretreated with FOLFOXIRI, suggesting the occurrence of resistance. We were unable to improve FOLFOXIRI in terms of efficacy or specificity. Improvement of CRC treatment should come from the optimization of targeted drugs and immunotherapy strategies.

Molecular mechanism of Poria cocos combined with oxaliplatin on the inhibition of epithelial-mesenchymal transition in gastric cancer cells

PURPOSE

Natural product Poria cocos possesses antitumor effect. This study will explore the molecular mechanism of Poria cocos combined with chemotherapy in the inhibition of gastric cancer cell EMT process.

METHODS

The experiment was divided into blank control group, Poria cocos group, oxaliplatin group and Poria cocos combined with oxaliplatin group. Scratch and Transwell assay were used to detect cell migration and invasion respectively. RT-qPCR and Western Blot analyses were used to detect mRNA and protein expression of the epithelial-mesenchymal transition (EMT) related factors including Snail, Twist, Vimentin, E-cadherin and N-cadherin respectively. Morphologic assessment was performed with HPIAS-1000 automated image analysis system.

RESULTS

The migration and invasion abilities of gastric cancer cells in the Poria cocos combined with oxaliplatin group were significantly decreased (P < 0.01). The mRNA and protein expression of Snail, Twist, Vimentin and N-cadherin were significantly decreased while the mRNA and protein expression of E-cadherin were significantly increased (P < 0.01) compared with blank control group. Nude mice model of gastric cancer was successfully established. Poria cocos combined with oxaliplatin could significantly inhibit gastric tumor progression. The expression of EMT related factors were consistent with in vitro study. Morphologic assessment showed that the nucleus area, perimeter, mean diameter, volume, long diameter and shape factor in the Poria cocos combined with oxaliplatin group were significantly different compared with the blank control group (P < 0.01) but not significantly different compared with the normal control.

CONCLUSIONS

Poria cocos combined with oxaliplatin could significantly inhibit the migration and invasion of gastric cancer cells. Through both in vitro and in vivo studies, it is confirmed that Poria cocos combined with oxaliplatin could significantly inhibit the EMT process of gastric cancer. Poria cocos combined with oxaliplatin could significantly affect the morphology changes of gastric cancer cells. These findings may provide a theoretical guidance for the clinical treatment of gastric cancer.

The efficacy and safety of hepatic arterial infusion of oxaliplatin plus intravenous irinotecan, leucovorin and fluorouracil in colorectal cancer with inoperable hepatic metastasis

Hepatic arterial infusion (HAI) was evaluated for different drugs to treat hepatic metastasis from colorectal cancer (CRC). Combination treatment with 5-fluorouracil (5-FU), leucovorin, oxaliplatin and irinotecan (FOLFOXIRI) is effective for CRC. A phase II study was conducted to evaluate concomitant HAI administration of oxaliplatin and intravenous leucovorin, 5-FU and irinotecan (FOLFIRI) for patients with inoperable liver metastasis, which had chemotherapy with oxaliplatin (OX) 85 mg/m(2) HAI plus systemic intravenous chemotherapy [leucovorin 200 mg/m(2), 5-FU 2400 mg/m(2) and irinotecan (IRI) 160 mg/m(2) in 48 hours]. We treated 24 patients. Neutropaenia was the most frequent toxicity. The main HAI-related toxicity was pain. Two patients (8%) obtained complete response and 17 patients (70%) partial response, giving an objective response rate of 78%. Median follow-up was 22.8 months, and median overall and disease-free survival times were 29 and 20 months, respectively. Therefore, OX HAI and intravenous FOLFIRI is feasible and effective in patients with metastatic CRC.

Cytotoxic effects of the newly-developed chemotherapeutic agents 17-AAG in combination with oxaliplatin and capecitabine in colorectal cancer cell lines

The use of heat shock protein 90 inhibitors like 17-allylamino-17-demethoxy-geldanamycin (17-AAG) has been recently introduced as an attractive anticancer therapy. It has been shown that 17-AAG may potentiate the inhibitory effects of some classical anticolorectal cancer (CRC) agents. In this study, two panels of colorectal carcinoma cell lines were used to evaluate the effects of 17-AAG in combination with capecitabine and oxaliplatin as double and triple combination therapies on the proliferation of CRC cell lines. HT-29 and all HCT-116 cell lines were seeded in culture media in the presence of different doses of the mentioned drugs in single, double, and triple combinations. Water-soluble tetrazolium-1 (WST-1) assay was used to investigate cell proliferation 24 h after treatments. Then, dose-response curves were plotted using WST-1outputs, and IC₅₀ values were determined. For double and triple combinations respectively 0.5 × IC₅₀ and 0.25 × IC₅₀ were used. Data was analyzed with the software CompuSyn. Drug interactions were analyzed using Chou-Talalay method to calculate the combination index (CI).The data revealed that 17-AAG shows a potent synergistic interaction (CI < 1) with oxaliplatin and capecitabine in double combinations (0.5 × IC₅₀) in both cell lines. In the case of triple combinations, the findings showed an antagonistic interaction (CI > 1) in HT-29 and a synergistic effect (CI < 1) in HCT-116 (0.25 × IC₅₀) cell lines. It was concluded that double combinations of 17-AAG with oxaliplatin or capecitabine might be effective against HCT-116 and HT-29 cell lines. However, in triple combinations, positive results were seen only against HCT-116. Further investigation is suggested to confirm the effectiveness of these combinations in clinical trials.

Preparation, characterisation and antitumour activity of β-, γ- and HP-β-cyclodextrin inclusion complexes of oxaliplatin

Three water-soluble oxaliplatin complexes were prepared by inclusion complexation with β-cyclodextrin (β-CD), γ-CD and HP-β-CD. The structures of oxaliplatin/CDs were confirmed by NMR, FTIR, TGA, XRD as well as SEM analysis. The results show that the water solubility of oxaliplatin was increased in the complex with CDs in 1:1 stoichiometry inclusion modes, and the cyclohexane ring of oxaliplatin molecule was deeply inserted into the cavity of CDs. Moreover, the stoichiometry was established by a Job plot and the water stability constant (Kc) of oxaliplatin/CDs was calculated by phase solubility studies, all results show that the oxaliplatin/β-CD complex is more stable than free oxaliplatin, oxaliplatin/HP-β-CD and oxaliplatin/γ-CD. Meanwhile, the inclusion complexes displayed almost twice as high cytotoxicity compared to free oxaliplatin against HCT116 and MCF-7 cells. This satisfactory water solubility and higher cytotoxic activity of the oxaliplatin/CD complexes will potentially be useful for their application in anti-tumour therapy.

Increasing doxorubicin activity against breast cancer cells using PPARγ-ligands and by exploiting circadian rhythms

BACKGROUND AND PURPOSE

Doxorubicin is effective against breast cancer, but its major side effect is cardiotoxicity. The aim of this study was to determine whether the efficacy of doxorubicin on cancer cells could be increased in combination with PPARγ agonists or chrono-optimization by exploiting the diurnal cycle.

EXPERIMENTAL APPROACH

We determined cell toxicity using MCF-7 cancer cells, neonatal rat cardiac myocytes and fibroblasts in this study.

KEY RESULTS

Doxorubicin damages the contractile filaments of cardiac myocytes and affects cardiac fibroblasts by significantly inhibiting collagen production and proliferation at the level of the cell cycle. Cyclin D1 protein levels decreased significantly following doxorubicin treatment indicative of a G1/S arrest. PPARγ agonists with doxorubicin increased the toxicity to MCF-7 cancer cells without affecting cardiac cells. Rosiglitazone and ciglitazone both enhanced anti-cancer activity when combined with doxorubicin (e.g. 50% cell death for doxorubicin at 0.1 μM compared to 80% cell death when combined with rosiglitazone). Thus, the therapeutic dose of doxorubicin could be reduced by 20-fold through combination with the PPARγ agonists, thereby reducing adverse effects on the heart. The presence of melatonin also significantly increased doxorubicin toxicity, in cardiac fibroblasts (1 μM melatonin) but not in MCF-7 cells.

CONCLUSIONS AND IMPLICATIONS

Our data show, for the first time, that circadian rhythms play an important role in doxorubicin toxicity in the myocardium; doxorubicin should be administered mid-morning, when circulating levels of melatonin are low, and in combination with rosiglitazone to increase therapeutic efficacy in cancer cells while reducing the toxic effects on the heart.

Curcumin combined with oxaliplatin effectively suppress colorectal carcinoma in vivo through inducing apoptosis

Studies have shown chemopreventive and/or chemotherapeutic effects of several curcumin-based combinatorial treatments on colorectal cancer cells. However, their in vivo effects remain unclear. This study has demonstrated the therapeutic effect of curcumin and oxaliplatin, alone or in combination, on subcutaneously xenografted LoVo human colorectal cancer cells in immunodeficient (nu/nu) mice in vivo. Combinatorial administration of curcumin and oxaliplatin evidently inhibited the growth of colorectal cancer in nude mice, which was significantly more effective than either agent alone. Curcumin combined with oxaliplatin treatment induced apoptosis, accompanied by ultrastructural changes and cell cycle arrest in S and G2/M phases. Further mechanism analysis indicated that while the number of apoptotic tumor cells and the expression of Bax, caspase-3, and poly (ADP-ribose) polymerase (PARP) increased significantly, the expression of Bcl-2, survivin, HSP70, pro-caspase-3, and pro-PARP were dramatically suppressed in tumor cells after the treatment with combinatorial curcumin and oxaliplatin for 22 days. Taken together, the present study has demonstrated that administration of combined curcumin and oxaliplatin effectively suppressed colorectal carcinoma in vivo through inducing apoptosis and thus may provide an effective treatment for colorectal carcinoma.

Anti-tumor activity of liposome encapsulated fluoroorotic acid as a single agent and in combination with liposome irinotecan

To test the hypothesis that co-delivery of synergistic drug combinations in the same liposome provides a better anti-tumor effect than the drugs administered in separate liposomes, fluoroorotic acid (FOA) alone and in combination with irinotecan (IRN) were encapsulated in liposomes and evaluated for their anti-tumor activity in the C26 colon carcinoma mouse model. A new chaotropic loading strategy was devised wherein FOA was dissolved in 7 M urea to increase its solubility. This enabled the passive loading of FOA into liposomes at a high concentration. IRN was remote loaded into liposomes that contained the ammonium salt of the multi-valent 1,2,3,4-butanetetracarboxylic acid with a greater than 90% efficiency and at a drug to lipid ratio of 0.2:1. When the two molecules were loaded into the same liposome, FOA was used to remote load IRN. Modulation of the drug/lipid ratio, temperature, and loading time allowed for consistent co-encapsulation of FOA+IRN at various molar ratios. The anti-tumor activity of L-FOA, L-IRN, L-FOA-IRN (5:1), and the L-FOA+L-IRN mixture (5:1) were examined in the C26 mouse model. The maximum tolerated dose of L-FOA was 10 mg/kg given weekly as compared to 100 mg/kg of the non-encapsulated FOA. Delivering two drugs in the same liposome provided a statistically better anti-tumor effect than delivering the drugs in separate liposomes at the same drug ratio. However, the synergistic activity of the 5:1 ratio of free drugs measured on C26 cells in vitro was not observed in the C26 tumor mouse model. These findings point out the challenges to the design of synergistic treatment protocols based upon results from in vitro cytotoxicity studies. L-FOA at 10 mg/kg as a single agent provided the best anti-tumor efficacy which supports previous suggestions that L-FOA has useful properties as a liposome dependent drug.

Safety and efficacy of weekly 5-fluorouracil/folinic acid/oxaliplatin/irinotecan in the first-line treatment of gastrointestinal cancer

BACKGROUND

Standard chemotherapy for patients with metastatic colorectal cancer (mCRC) or gastric cancer (GC) consists of two-drug, usually fluoropyrimidine-based, combinations, with or without the addition of biological agents. Studies of triple-drug regimens combining 5-fluorouracil (5-FU)/folinic acid (FA) with both oxaliplatin and irinotecan have shown promising efficacy in studies of patients with mCRC or GC. However, improved efficacy has often been achieved at the expense of high rates of grade 3 or 4 toxicities such as neutropenia and diarrhoea, occasionally even resulting in toxic deaths.

OBJECTIVE/METHODS

We performed a phase II study of previously untreated patients with mCRC or GC to assess the safety and efficacy of our 5-fluorouracil/folinic acid/oxaliplatin/irinotecan (FUFOXIRI) regimen with weekly administration of irinotecan 70 mg/m(2), oxaliplatin 50 mg/m(2), FA 500 mg/m(2) and 5-FU 2000 mg/m(2) on days 1, 8, 15 and 22, repeated from day 36.

RESULTS

A total of 22 patients were enrolled, 11 each with mCRC and GC receiving a median of four cycles per patient. The FUFOXIRI regimen was generally well tolerated with no toxic deaths, neutropenic fever or grade 4 toxicities. Most common grade 3 side effects were diarrhoea and neutropenia each affecting 24% of patients. Dose reductions due to toxicity were performed in 48% of all and 60% of patients having received at least two cycles of FUFOXIRI. The overall response rate was 46% (all partial responses), 55% and 36% for patients with mCRC and GC, respectively. Median progression-free survival for all patients, mCRC and GC patients was 9.5, 10.0 and 8.0 months, respectively. The median overall survival for all patients was 16.5, 18.0 and 15.0 months for patients with mCRC and GC, respectively.

CONCLUSION

These data show excellent tolerance and efficacy of the FUFOXIRI regimen in both mCRC and GC. Therefore, FUFOXIRI is a promising backbone for future studies incorporating biologic 'targeted' agents for the treatment of gastrointestinal cancers.

Metronomic 5-fluorouracil, oxaliplatin and irinotecan in colorectal cancer

Metronomic chemotherapy (the frequent, long term, low dose administration of chemotherapeutic drugs) is a promising therapy because it enhances the anti-endothelial activity of conventional chemotherapeutics, but with lower or no toxic effects compared to maximum tolerated dose administration. The aims of the present study were to compare, in vitro and in vivo, the antiangiogenic and antitumor activities of metronomic irinotecan (CPT-11), oxaliplatin (L-OHP) and 5-fluorouracil (5-FU) in colorectal cancer and to investigate the metronomic combination of these drugs. In vitro cell proliferation, combination studies and vascular endothelial growth factor (VEGF) secretion analyses were performed on endothelial (HMVEC-d) and colorectal cancer (HT-29) cells exposed for 144 h to metronomic concentrations of SN-38, the active metabolite of CPT-11, L-OHP and 5-FU. HT-29 human colorectal cancer xenograft model was used and tumour growth, microvessel density and VEGF quantification were performed in tumours after the administration of metronomic CPT-11, L-OHP, 5-FU and their simultaneous combination. Low concentrations of SN-38, but not 5-FU and L-OHP, preferentially inhibited endothelial cell proliferation. Simultaneous and continuous exposure of HT-29 and HMVEC-d cells to low concentrations SN-38+L-OHP+5-FU for 144 h showed a strong antagonism and an unfavorable dose-reduction index. Moreover, the ternary combination resulted in a significant increase of VEGF secretion in HT-29 cancer cells. In a xenograft model metronomic CPT-11, but not 5-FU and L-OHP, significantly inhibits HT-29 tumor growth and microvessel density in the absence of toxicity. On the contrary, metronomic 5-FU+L-OHP+CPT-11 therapy did not affect the microvascular count. The metronomic concept might not universally apply to every cytotoxic drug in colorectal cancer and metronomic combination regimens should be used with caution.

Capecitabine plus oxaliplatin and irinotecan regimen every other week: a phase I/II study in first-line treatment of metastatic colorectal cancer

BACKGROUND

A phase I/II study was performed to determine the safety and activity of a capecitabine plus oxaliplatin and irinotecan (COI) regimen using capecitabine concurrently with oxaliplatin and irinotecan in previously untreated patients with metastatic colorectal cancer.

PATIENTS AND METHODS

Patients received irinotecan on day 1, oxaliplatin (85 mg/m(2)) on day 2 and capecitabine (1000 mg/m(2) orally twice daily) on days 2-6 of a biweekly schedule. Three dose levels ranging from 150 to 180 mg/m(2) were explored for irinotecan in sequential cohorts of three to six patients. Once the recommended dose was determined, a total of 28 eligible patients were planned at this dose level.

RESULTS

Thirty-eight patients received a median of six cycles. The recommended phase II dose of irinotecan was 180 mg/m(2). Toxicity was manageable: the most common severe toxicities were diarrhoea (24%) and nausea (16%). Of 27 assessable patients treated at the recommended dose, 17 achieved a partial response (overall response rate (ORR) 63%; 95% confidece interval (CI), 44 to 78%), with eight patients undergoing liver metastasectomy. Estimated progression-free survival and overall median survival were 8.5 and 23.5 months, respectively.

CONCLUSIONS

Biweekly COI is feasible and active. Tolerability and ease of administration make the regimen well suited for downsizing hepatic colorectal metastases before curative surgery.

Chronomodulated irinotecan, oxaliplatin, and leucovorin-modulated 5-Fluorouracil as ambulatory salvage therapy in patients with irinotecan- and oxaliplatin-resistant metastatic colorectal cancer

PURPOSE

To evaluate the activity and tolerability of salvage chronomodulated chemotherapy combining irinotecan (I), 5-fluorouracil/leucovorin (5-FU/LV), and oxaliplatin (O) (chronoIFLO) in patients with metastatic colorectal cancer (MCRC) and prior progression on four drugs.

PATIENTS AND METHODS

Seventy-seven nonhospitalized MCRC patients received chronoIFLO every 3 weeks, with day 1: I (180 mg/m2 over 6 hours, with peak infusion rate at 05:00) and days 2-5: 5-FU/LV (700/300 mg/m2 per day over 12 hours, with peak flow rate at 04:00), and O (20 mg/m2 per day over 12 hours, with peak flow rate at 16:00). Toxicity and response were assessed every 3 weeks and every 2 months, respectively. RESULTS. Three or more prior chemotherapy lines were given to 75% of the patients. Two or more organs had metastatic disease in 65% of the patients. A median number of six courses of chronoIFLO was given. The main grade 3-4 toxicities were diarrhea (39% of the patients, 9% of the courses) and neutropenia (30% of the patients and 7% of the courses). Grade 3 peripheral sensory neuropathy occurred in 14% of the patients. Two patients achieved a partial response and 61 had stable disease, resulting in disease control for 82% of the patients. The median time to progression (TTP) was 5.5 months (95% confidence interval, 3.7-6.0). The median overall survival time was 14.2 months (9.8-17.3). Baseline performance status, serum carcinoembryonic antigen (CEA) level, and CEA doubling time were independent prognostic factors of TTP.

CONCLUSIONS

ChronoIFLO safely and durably halted tumor progression in most extensively pretreated MCRC patients.

Biweekly oxaliplatin plus irinotecan and folinic acid-modulated 5-fluorouracil: a phase II study in pretreated patients with metastatic colorectal cancer

Oxaliplatin (OXA) and irinotecan (IRI) are active drugs for metastatic colorectal cancer, their toxicity profiles are not overlapping, and both drugs have shown at least additivity with folinic acid-modulated 5-fluorouracil (5FU). We carried out this phase II study to assess the activity and toxicity of a biweekly regimen including OXA plus IRI on day 1, and levo-folinic acid (LFA) plus 5FU on day 2 (OXIRIFAFU) in pretreated patients with metastatic colorectal cancer. Forty-one patients, all previously treated with adjuvant and/or palliative 5FU-based chemotherapy (16 of them already exposed to IRI, OXA or both), were enrolled into this trial. On the basis of sensitivity to previous treatment, 19 patients were considered as chemo-resistant and 14 patients as chemo-refractory. OXA 110 mg/m (over 2 h) and IRI 175 mg/m (over 1 h) were delivered on day 1, followed by LFA 250 mg/m (2-h infusion) plus 5FU 800 mg/m as intravenous bolus on day 2. Cycles were repeated every 2 weeks. A total of 348 cycles were delivered, with a median of nine cycles per patient (range, 1-12 cycles per patient). Five complete and 13 partial responses were reported on 40 assessable patients, giving a response rate of 45% [95% confidence interval (CI), 29-62%]; eight of 19 (42%) resistant patients and five of 14 (36%) refractory patients achieved a major response, which was also obtained in four of eight (50%) patients pretreated with IRI and in three of eight (38%) patients pretreated with OXA. Grade 3 or higher neutropenia occurred in 68% of patients, but febrile neutropenia or infections affected only seven (17%) patients. No episodes of grade 3 or higher thrombocytopenia or anemia were recorded. Occurrence of severe non-hematologic toxicities by patients were: diarrhea, 34%; vomiting, 17%; peripheral cumulative neuropathy, 15%; stomatitis, 10%; acute cholinergic syndrome, 7%. Actually delivered dose intensities of all three drugs resulted in about two-thirds of the planned ones. After a follow-up of 39 months, median progression-free survival was 7.5 months. Median overall survival was 14.4 (95% CI, 10.4-18.4) months from the start of OXIRIFAFU and 25.3 (95% CI, 18.1-32.5) months from the diagnosis of metastatic disease. This OXIRIFAFU triplet regimen was highly effective in resistant/refractory colorectal cancer patients. A slight dose reduction of all cytotoxic drugs could be advisable in order to improve the tolerability of this regimen without jeopardizing its activity.

Theoretical basis, experimental design, and computerized simulation of synergism and antagonism in drug combination studies

The median-effect equation derived from the mass-action law principle at equilibrium-steady state via mathematical induction and deduction for different reaction sequences and mechanisms and different types of inhibition has been shown to be the unified theory for the Michaelis-Menten equation, Hill equation, Henderson-Hasselbalch equation, and Scatchard equation. It is shown that dose and effect are interchangeable via defined parameters. This general equation for the single drug effect has been extended to the multiple drug effect equation for n drugs. These equations provide the theoretical basis for the combination index (CI)-isobologram equation that allows quantitative determination of drug interactions, where CI < 1, = 1, and > 1 indicate synergism, additive effect, and antagonism, respectively. Based on these algorithms, computer software has been developed to allow automated simulation of synergism and antagonism at all dose or effect levels. It displays the dose-effect curve, median-effect plot, combination index plot, isobologram, dose-reduction index plot, and polygonogram for in vitro or in vivo studies. This theoretical development, experimental design, and computerized data analysis have facilitated dose-effect analysis for single drug evaluation or carcinogen and radiation risk assessment, as well as for drug or other entity combinations in a vast field of disciplines of biomedical sciences. In this review, selected examples of applications are given, and step-by-step examples of experimental designs and real data analysis are also illustrated. The merging of the mass-action law principle with mathematical induction-deduction has been proven to be a unique and effective scientific method for general theory development. The median-effect principle and its mass-action law based computer software are gaining increased applications in biomedical sciences, from how to effectively evaluate a single compound or entity to how to beneficially use multiple drugs or modalities in combination therapies.

Multiple-target Chemotherapy (Lv-modulated 5-FU Bolus and Continuous Infusion, Oxaliplatin, CPT-11) in Advanced 5-Fu-refractory Colorectal Cancer: Mtd Definition and Efficacy Evaluation. A Phase I-II Study

Aims and Background

To identify the maximum tolerated doses and to define the activity of a regimen incorporating leucovorin (LV)-modulated 5-fluorouracil (5-FU) bolus and continuous infusion, oxaliplatin (I-OHP) and irinotecan (CPT-11) in patients with advanced, 5-FU-refractory colorectal cancer (CRC).

Patients and Methods

Starting doses: LV 100 mg/m2 as a 2-hour infusion followed by 5-FU 300 mg/m2 bolus administration followed by 5-FU 500 mg/m2 as a 22-hour infusion on days 1 and 2; I-OHP 65 mg/m2 as a 2-hour infusion concomitantly with LV on day 1; CPT-11 90 mg/m2 concomitantly with LV on day 2. Planned cycle interval: 2 weeks.

Results

Two hundred twenty-six cycles were administered to 27 patients. Recommended doses were 5-FU bolus 300 mg/m2, 5-FU protracted infusion 500 mg/m2, l-OHP 75 mg/m2, and CPT-11 150 mg/m2. Among 25 patients evaluable for response we observed 13 disease stabilizations (52%; 95% CI: 33-71%), 6 instances of disease progression and 6 responses (24%; 95% CI: 7-41%). Median time to progression and overall survival were 24 and 60 weeks, respectively. A cycle delay >3 days was observed in 134/199 cycles (67%).

Conclusions

This study confirms the feasibility of triplet chemotherapy in patients with advanced 5-FU-refractory CRC.

Metastatic colorectal cancer

Metastatic colorectal cancer remains a public-health issue on a global scale. With development of a new generation of cytotoxic agents, survival has improved for patients with metastatic disease. How to maximize the benefit of chemotherapy with acceptable toxicity remains incompletely answered. Hepatic resection can provide a significant hope for long term survival, and a subset of patients might benefit from perioperative approaches. More recently, specific molecular processes have been targeted for therapeutic interventions, and encouraging results have been achieved using inhibitors of the Epidermal Growth Factor Receptor and the Vascular Endothelial Growth Factor.

An alternating regimen of irinotecan/ 5-fluorouracil/folinic acid and oxaliplatin/ 5-fluorouracil/folinic acid in metastatic colorectal cancer: a Phase II trial

OBJECTIVE

To assess the feasibility and activity of a combination schedule with irinotecan (CPT-11), oxaliplatin (L-OHP), brief infusional fluorouracil (5-FU) and folinic acid (FA) as first-line treatment in metastatic colorectal cancer (MCC) patients.

METHODS

Fifty consecutive patients were treated with CPT-11 125 mg/m2 as a 90-min intravenous infusion, followed by FA 20 mg/m2 as an intravenous bolus, and 5-FU 500 mg/m2 over a 2-hour intravenous infusion on days 1 and 8. L-OHP was administered at 85 mg/m2 over 2 h on day 15, in combination with a FA 60 mg/m2 intravenous bolus and 5-FU 600 mg/m2 as a 2-hour intravenous infusion on days 15-16. The treatment was repeated every 4 weeks for a maximum of 9 cycles.

RESULTS

Twenty-five of 50 assessable patients achieved a complete (n=5) or partial (n=20) response, leading to a response rate of 50% (95% CI 35-64%). Eighteen (36%) patients showed stable disease. The median time to tumor progression was 10.3 months (95% CI 9.6-10.9 months). After a median follow-up of 16.4 months, the median survival was not reached. Grade 3 neutropenia (8%), grade 3 nausea/vomiting (6%) and grade 3 diarrhea (2%) were the major adverse events.

CONCLUSION

This alternating three-drug regimen is very well tolerated, manageable and effective in terms of activity and time to progression.

A review of oxaliplatin and its clinical use in colorectal cancer

Colorectal cancer is one of the leading causes of death from malignant diseases in the Western world. Worldwide, approximately 50% of patients who present with colorectal cancer will develop metastatic disease and eventually die from this malignancy. Recently, significant advances have been made in the medical treatment of advanced colorectal cancer with the introduction of novel cytotoxic drugs, such as irinotecan and oxaliplatin. Based on the results of recent Phase III trials, combination regimens of infusional 5-fluorouracil/leucovorin and oxaliplatin (FOLFOX) have emerged as a new standard of care in the palliative and adjuvant treatment of colorectal cancer. The addition of biological agents targeting angiogenesis or oncogenes such as epidermal growth factor receptor (EGFR) to FOLFOX will conceivably further enhance the activity of treatment regimens. Making use of all available active therapeutic options in the course of disease has significantly improved median overall survival of metastatic colorectal cancer into a chronic disease, with implications for treatment strategies and pharmacoeconomic considerations.

Second-line therapy for advanced colorectal carcinoma

The past decade has witnessed considerable advances in the treatment of colorectal cancer (CRC). The emergence and integration into clinical practice of new cytotoxic agents, such as irinotecan and oxaliplatin, has had a significant impact on outcomes from advanced CRC with median survivals of 18 to 21 months now achievable. Improvements in survival as a consequence of using these drugs as salvage therapies ultimately led to demonstration of efficacy for both in the first-line treatment of CRC. As the importance of second-line therapy is increasingly recognized, key issues, such as optimal schedules, chemotherapy combinations, and sequential therapy, need to be addressed. The integration of newer biologic agents, such as cetuximab and bevacizumab, for which recent data have emerged, has further added to the complexities of delivering therapy to patients with advanced CRC, heralding a new treatment era for this disease.

First-line treatment of metastatic colorectal cancer with irinotecan, oxaliplatin and 5-fluorouracil/leucovorin (FOLFOXIRI): results of a phase II study with a simplified biweekly schedule

BACKGROUND

In a previous phase I-II study we demonstrated that the FOLFOXIRI regimen [irinotecan 125-175 mg/m2 day 1, oxaliplatin 100 mg/m2 day 1, l-leucovorin (l-LV) 200 mg/m2 day 1, 5-fluorouracil (5-FU) 3800 mg/m2 as a 48-h chronomodulated continuous infusion starting on day 1, repeated every 2 weeks] has promising activity and efficacy in metastatic colorectal cancer. However, this regimen required a chronomodulated infusion of 5-FU, and because neutropenia occurred in 32% of cycles, granulocyte colony-stimulating factor (G-CSF) was used and the delivered dose intensity was only approximately 78% of planned. Therefore, we conducted the present phase II study in order to develop a simplified FOLFOXIRI regimen that could be more easily administered in clinical practice as well as in multicenter settings.

PATIENTS AND METHODS

A total of 32 patients with unresectable metastatic colorectal cancer received irinotecan 165 mg/m2 day 1, oxaliplatin 85 mg/m2 day 1, l-LV 200 mg/m2 day 1 and 5-FU 3200 mg/m2 as a 48-h continuous (not chronomodulated) infusion starting on day 1, repeated every 2 weeks.

RESULTS

All 32 patients were evaluated for safety and the incidence of grade 3-4 toxic effects, and the use of G-CSF seemed to be lower than with the previous FOLFOXIRI regimen: grade 4 neutropenia (34%), grade 3 diarrhea (16%), grade 3 stomatitis (6%) and grade 2-3 peripheral neurotoxicity (37%) were reported, and G-CSF was used in 23% of cycles. Delivered dose intensity was 88% of that planned, and no toxic deaths occurred. The intention-to-treat analysis for activity showed four complete responses, 19 partial responses, seven stable disease and two progressive disease, for an overall response rate of 72% (95% confidence interval 53% to 86%). Eight (25%) patients with residual liver or lung metastases were radically resected after chemotherapy. After a median follow-up of 18.1 months, the median progression-free survival is 10.8 months and median survival is 28.4 months.

CONCLUSIONS

This simplified FOLFOXIRI combination can be delivered easily in outpatient settings, with manageable toxic effects, and has very promising antitumor activity. While the safety profile seems to be improved in comparison with our previous FOLFOXIRI regimen, antitumor activity and efficacy appear to be maintained.

Efficacy of Treatment with Irinotecan and Oxaliplatin Combination in FU-Resistant Metastatic Colorectal Cancer Patients

OBJECTIVES

As single agents, irinotecan and oxaliplatin are active in colorectal cancer after fluorouracil (FU)-containing regimen failure. Their synergistic activity and non-overlapping toxicity profile are well documented, but more data are needed to explore their exact sequence. The aim of this study was to evaluate the activity and tolerability of irinotecan followed by oxaliplatin in patients with FU-resistant colorectal cancer.

METHODS

FU resistance was defined as disease progression during or within 6 months of discontinuing first-line or adjuvant FU/leucovorin chemotherapy. The study treatment consisted of irinotecan 150 mg/m(2) on days 1 and 8 followed by oxaliplatin 85 mg/m(2) on day 1 every 3 weeks. In order to improve the safety profile, we changed the schedule during the study to irinotecan 300 mg/m(2) on day 1 and oxaliplatin 85 mg/m(2) on day 2 every 3 weeks.

RESULTS

Of 54 patients treated, the 45 patients with measurable disease were assessed in the efficacy analysis, whereas all patients receiving at least one cycle were evaluated in the safety analysis. Of the patients assessed for efficacy analysis, 19 cases received the first schedule and 26 patients received the second schedule. Twenty-two patients (49%) responded, 10 of the first schedule and 12 of the second schedule group. Stable disease was observed in 35% of all patients. The median response duration was 6.5 months (range 3-10), the median time to progression was 8 months (range 6-10), and the overall survival was 15 months (10-26+). The NCI-CTC grade 3 side effects documented in all of the treated patients were: nausea/vomiting (11%), diarrhea (18%), and neutropenia (7%); grade 4 diarrhea was observed in 2% of patients.

CONCLUSION

The combination of irinotecan followed by oxaliplatin combination is well tolerated and highly active in FU-resistant metastatic colorectal cancer patients.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Cooperates with Anticancer Drugs to Overcome Chemoresistance in Antiapoptotic Bcl-2 Family Members Expressing Jurkat Cells

PURPOSE

Overexpression of antiapoptotic Bcl-2 family members has recently been related to resistance to chemo/radiotherapy in several human malignancies, particularly lymphomas. Hence, innovative approaches bypassing this resistance mechanism are required in the therapeutic approach. This study evaluated whether chemoresistance associated with Bcl-2 and Bcl-x(L) overexpression would be overcome by activating the death receptor pathway by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in the Jurkat cell model

EXPERIMENTAL DESIGN

We made use of genetically modified Jurkat cells to evaluate the effect of Bcl-2 or Bcl-x(L) overexpression on the cytotoxic effect produced by the anticancer drugs doxorubicin, etoposide, and oxaliplatin and TRAIL. Caspase activation was detected by cleavage of caspase-8 and -3. The mitochondrial transmambrane potential was assessed by staining with DiOC(6) and flow cytometry. Caspase activity was blocked by the broad-spectrum caspase inhibitor zVAD-fmk.

RESULTS

Bcl-2 and Bcl-x(L) overexpression but not lack of caspase-8 protects the Jurkat cells from the anticancer drug-induced cytolysis. However, Bcl-2/Bcl-x(L) Jurkat cells retained some susceptibility to TRAIL-induced cytolysis. A highly synergistic cytotoxic effect of the combination of TRAIL with any of the antiblastic used in this study was detected in the chemoresistant cells. This effect was associated with mitochondrial disassemblage and dependent on caspase activation

CONCLUSIONS

The combination of TRAIL with conventional anticancer drugs may prove to be useful in the treatment of antiapoptotic Bcl-2 family proteins-expressing malignancies.

Phase I and pharmacokinetic study of two different schedules of oxaliplatin, irinotecan, Fluorouracil, and leucovorin in patients with solid tumors

PURPOSE

We sought to determine the maximum-tolerated dose (MTD) and evaluate the toxicities and clinical activity of two irinotecan (CPT-11), fluorouracil (FU), leucovorin (LV), and oxaliplatin schedules in patients with advanced solid tumors. Additionally, we investigated the effect of CPT-11 on oxaliplatin pharmacokinetics.

PATIENTS AND METHODS

Thirteen patients (cohort 1) received intravenous CPT-11 (infusion) and FU/LV (bolus) on days 1, 8, 15, and 22 and oxaliplatin (infusion) on days 1 and 15 every 6 weeks for a total 37 courses (median, three courses) at three dose levels. Twenty-two cohort 2 patients received intravenous CPT-11/oxaliplatin (infusion, day 1) and FU/LV (90-minute bolus infusion, days 2 to 5) every 3 weeks for a total of 122 courses (median, four courses) at three dose levels. Pharmacokinetic and neurotoxicity assessments were performed at the cohort 2 MTD.

RESULTS

Dose-limiting toxicity (DLT) seen in both cohorts at the starting dose required dose de-escalation. Cohort 1 DLT included diarrhea and neutropenia. In cohort 2, diarrhea, vomiting, dehydration, neutropenia, febrile neutropenia, and paresthesias were DLTs. Antitumor activity was seen in both cohorts. In cohort 2, the total platinum area under the curve of patients increased 17% in cycle 2 (P =.048), but objective neurotoxicity was not seen.

CONCLUSION

The toxicities resulting from the addition of oxaliplatin to CPT-11/FU/LV are significant but manageable. The MTDs for the weekly schedule are CPT-11 (75 mg/m2), oxaliplatin (50 mg/m2), FU (320 mg/m2), and LV (20 mg/m2); and, for the 3-weekly schedule, the MTDs are CPT-11 (175 mg/m2), oxaliplatin (85 mg/m2), FU (240 mg/m2), and LV (20 mg/m2). Second-cycle platinum accumulation raises the possibility for enhanced cumulative neurotoxicity with CPT-11/oxaliplatin combinations.

Tumour-inhibiting platinum complexes--state of the art and future perspectives

Thirty years after the onset of the first clinical studies with cisplatin, the development of antineoplastic platinum drugs continues to be a productive field of research. This article reviews the current preclinical and clinical status, including a discussion of the molecular basis for the activity of the parent drug cisplatin and platinum drugs of the second and third generation, in particular their interaction with DNA. Further emphasis is laid on the development of third generation platinum drugs with activity in cisplatin-resistant tumours, particularly on chelates containing 1,2-diaminocyclohexane (DACH) and on the promising and more recently evolving field of non-classic ( trans- and multinuclear) platinum complexes. The development of oral platinum drugs and drug targeting strategies using liposomes, polymers or low-molecular-weight carriers in order to improve the therapeutic index of platinum chemotherapy are also covered.

Superiority of oxaliplatin and fluorouracil-leucovorin compared with either therapy alone in patients with progressive colorectal cancer after irinotecan and fluorouracil-leucovorin: interim results of a phase III trial

PURPOSE

In North America, no effective therapy has been available for patients with progressive metastatic colorectal cancer after front-line treatment with irinotecan, bolus fluorouracil (FU), and leucovorin (IFL).

PATIENTS AND METHODS

Patients with metastatic colorectal cancer who progressed after IFL therapy were randomly assigned to bolus and infusional FU and leucovorin (LV5FU2), single-agent oxaliplatin, or the combination (FOLFOX4). This planned interim analysis evaluated objective response rate (RR), time to tumor progression (TTP), and alleviation of tumor-related symptoms (TRS) in an initial cohort of patients.

RESULTS

Between November 2000 and September 2001, 463 patients from 120 sites in North America were randomly assigned to treatment. FOLFOX4 proved superior to LV5FU2 in all measures of clinical efficacy. Objective RRs determined by an independent radiology panel were 9.9% for FOLFOX4 versus 0% for LV5FU2 (Fisher's exact test, P <.0001). Median TTP was 4.6 months for FOLFOX4 versus 2.7 months for LV5FU2 (two-sided, stratified log-rank test, P <.0001). Relief of TRS occurred in 33% of patients treated with FOLFOX4 versus 12% of patients treated with LVFU2 (chi2 test, P <.001). Single-agent oxaliplatin was not superior to LV5FU2 in any measure of efficacy. Patients treated with FOLFOX4 experienced a higher incidence of clinically significant toxicities than patients treated with LV5FU2, but these toxicities were predictable and did not result in a higher rate of treatment discontinuation or 60-day mortality rate.

CONCLUSION

For patients with metastatic colorectal cancer, second-line treatment with FOLFOX4 is superior to treatment with LVFU2 in terms of RR, TTP, and relief of TRS.

Oxaliplatin plus irinotecan and leucovorin-modulated 5-fluorouracil triplet regimen every other week: a dose-finding study in patients with advanced gastrointestinal malignancies

BACKGROUND

Oxaliplatin (OXA) and irinotecan (IRI) are active drugs in first-line as well as second-line treatment of advanced colorectal cancer patients, their toxicity profiles are not overlapping, and both drugs have shown synergism with folinic acid-modulated 5-fluorouracil (5-FU). We planned this phase I study to define the dose-limiting toxicities (DLTs), the maximum tolerated doses (MTDs), and the recommended doses (RDs) for a triplet regimen including OXA plus IRI on day 1, and 6S-folinic acid (LFA) plus 5-FU on day 2, every 2 weeks.

PATIENTS AND METHODS

At least three patients had to be treated at each dose level, and the trial proceeded if no more than 33% of patients showed a DLT after the first cycle. Starting from OXA 85 mg/m(2) (over 2 h) and IRI 150 mg/m(2) (over 1 h), an alternated escalation was planned up to 110 mg/m(2) and 200 mg/m(2), respectively. Thereafter, a fixed dose of LFA, 250 mg/m(2) (as 2-h infusion), plus an escalating dose of 5-FU (from 650 to 800 mg/m(2) as an intravenous bolus) was added on day 2 to the previous dose level of OXA and IRI.

RESULTS

Forty-six patients, all but four affected by advanced colorectal primaries, entered this study. The MTDs for OXA and IRI given on the same day were 110 and 200 mg/m(2): these doses caused a DLT in three of six patients. The previous dose level (110 and 175 mg/m(2), respectively) on day 1 was safely followed on day 2 by LFA plus 5-FU up to 800 mg/m(2). Indeed, only one of three patients treated at this last level had a DLT. This cohort was then expanded including a total of 14 patients, and on the whole series five cases of DLT occurred: WHO grade 4 neutropenia (two patients), grade 3 or 4 diarrhoea (three patients). Cumulative toxicity was analysed in 43 patients for a total of 347 cycles: grade 4 neutropenia was detected in 13 patients (30%); it was not dose-related, nor was it exacerbated by the addition of modulated 5-FU. Febrile neutropenia occurred in four patients. Grade 3 or 4 diarrhoea was suffered by nine (21%) and five (12%) patients, respectively. Two complete and nine partial responses were reported on 40 evaluable patients (six patients were disease-free at study entry), giving a response rate of 27.5% (95% confidence interval 15% to 44%); nine of 18 (50%) assessable patients of the two last cohorts treated with the triplet regimen achieved a complete response (two patients) or a partial response (seven patients).

CONCLUSIONS

The RDs for this biweekly regimen were: OXA 110 mg/m(2) plus IRI 175 mg/m(2) on day 1, and LFA 250 mg/m(2) plus 5-FU 800 mg/m(2) on day 2. This regimen appeared active in pretreated gastrointestinal malignancies, and it is worthy of being evaluated in advanced colorectal carcinoma after failure of 5-FU-based adjuvant or palliative treatment.

Contribution of apoptosis in the cytotoxicity of the oxaliplatin-irinotecan combination in the HT29 human colon adenocarcinoma cell line

Interactions between the topoisomerase I inhibitor irinotecan (CPT-11) and the platinum derivative oxaliplatin (L-OHP) were investigated in HT29 colon cancer cell line. Synergism was observed when cells were simultaneously exposed to drugs or when cells were first exposed to CPT-11. Flow cytometric studies showed a G(2)/M accumulation when cells were exposed to the simultaneous and CPT-11-->L-OHP combinations whereas a persistent S phase delay was observed when cells were first exposed to L-OHP. We characterised the cytotoxic effect by assessing the induction of apoptosis. Irinotecan induced substantial DEVDase activity and poly(ADP-ribose) polymerase cleavage while this activity was moderate and delayed after exposure to L-OHP. Combination experiments showed a sequence-dependent onset of apoptosis, the CPT-11-->L-OHP schedule being the earliest and the most effective; on the other hand the apoptotic signaling generated by CPT-11 was partly inhibited in the simultaneous combination and in the L-OHP-->CPT-11 sequence. Cell death studies using a dual staining technique showed a shift from apoptosis to necrosis when combining these drugs at high concentrations. Synergistic interactions observed using CPT-11 before L-OHP may be linked to an early apoptotic signaling while the L-OHP-induced S phase block could account for the observed additive effect in the reverse sequence. An additional phenomenon might work towards synergism for the simultaneous combination.

Biweekly chemotherapy with oxaliplatin, irinotecan, infusional Fluorouracil, and leucovorin: a pilot study in patients with metastatic colorectal cancer

PURPOSE

To determine the feasibility, recommended doses, plasma pharmacokinetics, and antitumor activity of a biweekly chemotherapy regimen with oxaliplatin (L-OHP), irinotecan (CPT-11), infusional fluorouracil (5-FU), and leucovorin (LV) in metastatic colorectal cancer patients.

PATIENTS AND METHODS

Patients received CPT-11 followed by L-OHP and LV 200 mg/m(2) and followed by 5-FU 3,800 mg/m(2) as a 48-hour infusion, repeated every 2 weeks. In the first part of the study, an escalation of CPT-11 dose and/or a decrease of the L-OHP dose were planned. Once the recommended doses of CPT-11 and L-OHP were determined, all subsequent patients were treated at the recommended doses.

RESULTS

Forty-two patients entered the study. CPT-11 175 mg/m(2) and L-OHP 100 mg/m(2) in combination with LV 200 mg/m(2) and 5-FU 3,800 mg/m(2) could be administered with acceptable toxicities; 39 patients were treated at these dose levels. The pharmacokinetics parameters of the agents used and their metabolites did not seem to be influenced by the concomitant use of the other drugs. The most relevant toxicities were diarrhea and neutropenia, with 14% of patients experiencing one episode of febrile neutropenia. In five patients (11.9%) a complete and in 25 (59.5%) a partial response was demonstrated, for an objective response rate of 71.4% (95% confidence interval, 47% to 83%). In 11 patients (26%), a surgical resection of residual disease could be performed. Median progression-free and overall survival times were 10.4 and 26.5 months, respectively.

CONCLUSION

This biweekly regimen is feasible and has acceptable and manageable toxicities and no apparent relevant pharmacokinetics interactions. This combination is associated with a promising antitumor activity, time to progression, and survival. A phase III randomized trial in Italy planned by the Gruppo Oncologico Nord Ovest has just started.