Irinotecan, oxaliplatin, and 5-fluorouracil/leucovorin combination chemotherapy in advanced colorectal carcinoma: a phase II study

Overcoming Irinotecan Resistance by Targeting Its Downstream Signaling Pathways in Colon Cancer

Among the most popular chemotherapeutic agents, irinotecan, regarded as a prodrug belonging to the camptothecin family that inhibits topoisomerase I, is widely used to treat metastatic colorectal cancer (CRC). Although immunotherapy is promising for several cancer types, only microsatellite-instable (~7%) and not microsatellite-stable CRCs are responsive to it. Therefore, it is important to investigate the mechanism of irinotecan function to identify cellular proteins and/or pathways that could be targeted for combination therapy. Here, we have determined the effect of irinotecan treatment on the expression/activation of tumor suppressor genes (including p15Ink4b, p21Cip1, p27Kip1, and p53) and oncogenes (including OPN, IL8, PD-L1, NF-κB, ISG15, Cyclin D1, and c-Myc) using qRT-PCR, Western blotting, immunofluorescence (IF), and RNA sequencing of tumor specimens. We employed stable knockdown, neutralizing antibodies (Abs), and inhibitors of OPN, p53, and NF-κB to establish downstream signaling and sensitivity/resistance to the cytotoxic activities of irinotecan. Suppression of secretory OPN and NF-κB sensitized colon cancer cells to irinotecan. p53 inhibition or knockdown was not sufficient to block or potentiate SN38-regulated signaling, suggesting p53-independent effects. Irinotecan treatment inhibited tumor growth in syngeneic mice. Analyses of allograft tumors from irinotecan-treated mice validated the cell culture results. RNA-seq data suggested that irinotecan-mediated activation of NF-κB signaling modulated immune and inflammatory genes in mice, which may compromise drug efficacy and promote resistance. In sum, these results suggest that, for CRCs, targeting OPN, NF-κB, PD-L1, and/or ISG15 signaling may provide a potential strategy to overcome resistance to irinotecan-based chemotherapy.

The use of SP/Neurokinin-1 as a Therapeutic Target in Colon and Rectal Cancer

Different studies have highlighted the role of Substance P / Neurokinin 1 Receptor (SP/NK-1R) axis in multiple hallmarks of cancer including cell transformation, proliferation, and migration as well as angiogenesis and metastasis of a wide range of solid tumors including colorectal cancer. Until now, the selective high-affinity antagonist of human SP/NK1-R aprepitant (Emend) has been authorized by the Food and Drug Administration as a low dosage medication to manage and treat chemotherapy-induced nausea. However, increasing evidence in recent years support the potential utility of high doses of aprepitant as an antitumor agent and thus, opening the possibility to the pharmacological repositioning of SP/NK1-R antagonists as an adjuvant therapy to conventional cancer treatments. In this review, we summarize current knowledge on the molecular basis of colorectal cancer as well as the pathophysiological importance of SP/NK1-R and the potential utility of SP/NK-1R axis as a therapeutic target in this malignancy.

Efficacy and safety of chronomodulated irinotecan, oxaliplatin, 5-fluorouracil and leucovorin combination as first- or second-line treatment against metastatic colorectal cancer: Results from the International EORTC 05011 Trial

The triplet combination of irinotecan, oxaliplatin and fluorouracil is an active frontline regimen in metastatic colorectal cancer, but scarce data exist on its use as salvage treatment. We aimed at assessing its safety and efficacy profiles with its circadian-based administration (chronoIFLO5) as either first- or second-line treatment, within the time-finding EORTC 05011 trial. Five-day chronoIFLO5 was administered every 3 weeks in patients with PS 0, 1 or 2. It consisted of chronomodulated irinotecan (180 mg/sqm), oxaliplatin (80 mg/sqm) and fluorouracil-leucovorin (2800 and 1200 mg/sqm, respectively). For our study, toxicity and antitumour activity were evaluated separately in first- and second-line settings. Primary endpoints included Grade 3-4 toxicity rates, best objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). One-hundred forty-nine and 44 patients were treated in first-line and second-line settings, respectively, with a total of 1138 cycles with median relative dose intensities of about 90%. Demographics were comparable in the two groups. Thirty-six (24.7%) and 10 (22.2%) patients experienced at least one episode of severe toxicity in first line and second line, respectively. Frontline chronoIFLO5 yielded an ORR of 62.3% [95% CI: 54.2-70.4] and resulted in median PFS and OS of 8.7 months [7.5-9.9] and 19.9 months [15.4-24.5]. Corresponding figures in second line were 37.5% [22.5-52.5], 6.7 months [4.8-8.9] and 16.3 months [11.8-20.8]. International and prospective evaluation revealed the favourable safety and efficacy profiles of chronoIFLO5, both as frontline and as salvage treatment against metastatic colorectal cancer. In particular, encouraging activity in second line was observed, with limited haematological toxicity.

Targeting key transcriptional factor STAT3 in colorectal cancer

In developed countries, colorectal cancer (CRC) is the fourth most common cancer and the second leading cause of malignant-related deaths. CRC is treatable cancer when diagnosed early; however, diagnosis at the advanced stage is associated with a poor prognosis. Although chemotherapy is generally very promising, STAT3 protein which is overexpressed and persistently activated in CRC cells is observed to be the major contributor of chemoresistance development. It has been shown to play a prominent and pathogenic role in CRC initiation, progression, and metastasis. While over the past few years, research has been focused on STAT3 which is expressed at the center of various oncogenic pathways. This review is a discussion of the oncogenic role of STAT3 in CRC and potential therapeutic STAT3 inhibitors and analogs used to control and treat CRC.

Enhanced anti-colorectal cancer effects of carfilzomib combined with CPT-11 via downregulation of nuclear factor-κB in vitro and in vivo

Upregulation of nuclear factor-κB (NF-κB) in colorectal carcinoma (CRC) accelerates tumor growth, whereas, irinotecan (CPT-11)-induced NF-κB activation reduces chemosensitivity and weakens the anti-colorectal cancer function itself, while proteasome inhibitors can inhibit NF-κB and improve the effect of chemotherapy. Carfilzomib (CFZ) is a novel proteasome inhibitor that has been recently approved by the FDA and is in clinical use for the treatment of multiple myeloma, but little is known about its activity against CRC. The aim of the present study was to explore whether CFZ alone or in combination with CPT-11 is effective in CRC treatment. We evaluated the novel therapeutic ability and mechanism of action of CFZ in CRC in vitro and in vivo. SW620 cells were incubated with CFZ alone or in combination with CPT-11. Cell proliferation was assessed by WST-1 and clonogenic assays, the cytotoxic interaction was assessed with a combination index (CI). Cell cycle progression was analysed with flow cytometry. Cell apoptosis was evaluated by detecting the Annexin V/propidium iodide (PI) ratio, caspase 3 and CD95 expression, and with TUNEL staining. Cell migration and invasion was determined with a wound-healing assay and a Transwell matrix penetration assay. A CRC xenograft model was established to monitor tumor growth. EMSA was used to analyse NF-κB activation and western blot analysis was used to detect the protein levels of related signaling factors. CFZ significantly inhibited the growth of SW620 cells, and had synergistic inhibitory effects with CPT-11 on survival and colony formation; possibly by inhibition of NF-κB activation, MEK/ERK and PI3K/AKT pathway factor dephosphorylation and survivin downregulation. Co-administration of CFZ and CPT-11 induced G2/M arrest, increased p21WAF1/CIP, and decreased mutant p53 and cdc25c expression. Induction of apoptosis was accompanied by marked increases in PARP cleavage, caspase 3 activation, an increase of CD95 and p-p38, and ATF3 activation. Combination treatment lowered the invasive and migration ability of SW620 cells, reduced MMP and increased TIMP protein expression. Finally, co-administration of CFZ and CPT-11 suppressed tumor growth and increased apoptosis compared with single-agent treatment in SW620 xenograft models correlated with NF-κB downregulation. Carfilzomib alone or in combination with CPT-11 is effective against colorectal cancer through inhibition of multiple mechanisms related to NF-κB, and could be a potential novel therapy for CRC.

The new insight into oral drug delivery system based on metal drugs in colon cancer therapy through β-lactoglobulin/oxali-palladium nanocapsules

Many efforts have been made to improve the targeting and potential applications of oral drug delivery systems. In this paper, we have demonstrated and investigated how biopolymer nanocapsules can be used as a novel oral drug delivery system for metal-based drug delivery in colon cancer therapy. In this work, β-lactoglobulin nanocapsules containing oxali-palladium were chosen to be synthesized and investigated for the use in colon cancer therapy. These nanocapsules were fabricated in three different pHs (3, 4.5 and 7) and investigated both in the presence and absence of low methoxyl pectin. The results obtained from these experiments indicated that the soluble and stable β-lactoglobulin nanocapsules which contained oxali-palladium had the ability to be formed at a size smaller than 200 nm when in the presence of low methoxyl pectin and at pH 4.5. The in vitro release data indicated that the maximum release occurs at pH 7.0 and 7.5. There lease mechanism demonstrated an anomalous diffusion with a predominant contribution from erosion. Finally, it can be concluded that the β-LG nanocapsules containing oxali-palladium complexed with low methoxyl pectin can be a very promising candidate for the use in oral drug delivery for colon cancer treatment.

Synthesis of F16 conjugated with 5-fluorouracil and biophysical investigation of its interaction with bovine serum albumin by a spectroscopic and molecular modeling approach

5-Fluorouracil (5-FU) has been widely used as a chemotherapy agent in the treatment of many types of solid tumors. Investigation of its antimetabolites led to the development of an entire class of fluorinated pyrimidines. However, the toxicity profile associated with 5-FU is significant and includes diarrhea, mucositis, hand-foot syndrome and myelosuppression. In aiming at reducing of the side effects of 5-FU, we have designed and synthesized delocalized lipophilic cations (DLCs) as a vehicle for the delivery of 5-FU. DLCs accumulate selectively in the mitochondria of cancer cells because of the high mitochondrial transmembrane potential (ΔΨm). Many DLCs exhibited anti-cancer efficacy and were explored as potential anti-cancer drugs based on their selective accumulation in the mitochondria of cancer cells. F16, the DLC we used as a vehicle, is a small molecule that selectively inhibits tumor cell growth and dissipates mitochondrial membrane potential. The binding of the conjugate F16-5-FU to bovine serum albumin (BSA) was investigated using spectroscopic and molecular modeling approaches. Fluorescence quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between F16-5-FU and BSA. The activation energy of the interaction between F16-5-FU and BSA was calculated and the unusually high value was discussed in terms of the special structural block indicated by the molecular modeling approach. Molecular modeling showed that F16-5-FU binds to human serum albumin in site II, which is consistent with the results of site-competitive replacement experiments. It is suggested that hydrophobic and polar forces played important roles in the binding reaction, in accordance with the results of thermodynamic experiments.

Multi-tyrosine kinase inhibitors in preclinical studies for pediatric CNS AT/RT: Evidence for synergy with Topoisomerase-I inhibition

BACKGROUND

Currently, Atypical Teratoid Rhabdoid Tumor (AT/RT) constitutes one of the most difficult to treat malignancies in pediatrics. Hence, new knowledge of potential targets for therapeutics and the development of novel treatment approaches are urgently needed. We have evaluated the presence of cytokine pathways and the effects of two clinically available multi-tyrosine kinase inhibitors for cytotoxicity, target modulation and drug combinability against AT/RT cell lines.

RESULTS

AT/RT cell lines expressed measurable quantities of VEGF, FGF, PDGF and SDF-1, although the absolute amounts varied between the cell lines. The targeted receptor tyrosine kinase inhibitor sorafenib inhibited the key signaling molecule Erk, which was activated following the addition of own conditioned media, suggesting the existence of autocrine/paracrine growth stimulatory pathways. The multi-tyrosine kinase inhibitors sorafenib and sunitinib also showed significant growth inhibition of AT/RT cells and their activity was enhanced by combination with the topoisomerase inhibitor, irinotecan. The loss of cytoplasmic NF-kappa-B in response to irinotecan was diminished by sorafenib, providing evidence for a possible benefit for this drug combination.

CONCLUSIONS

In addition to previously described involvement of insulin like growth factor (IGF) family of cytokines, a multitude of other growth factors may contribute to the growth and survival of AT/RT cells. However, consistent with the heterogeneous nature of this tumor, quantitative and qualitative differences may exist among different tumor samples. Multi-tyrosine kinase inhibitors appear to have effective antitumor activity against all cell lines studied. In addition, the target modulation studies and drug combinability data provide the groundwork for additional studies and support the evaluation of these agents in future treatment protocols.

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.

Oxaliplatin, irinotecan and capecitabine as first-line therapy in metastatic colorectal cancer (mCRC): a dose-finding study and pharmacogenomic analysis

Background:

A dose-finding study was performed to evaluate the dose-limiting toxicity (DLT), maximum-tolerated dose (MTD) and the recommended dose (RD) of escalating the doses of capecitabine and fixed doses of irinotecan and oxaliplatin on a biweekly schedule for metastatic colorectal cancer patients (mCRC). A pharmacogenomic analysis was performed to investigate the association between SNPs and treatment outcome.

Methods:

Eighty-seven chemotherapy-naïve mCRC patients were recruited through a two-step study design; 27 were included in the dose-finding study and 60 in the pharmacogenomic analysis. Oxaliplatin (85 mg m^-2) and CPT-11 (150 mg m^-2), both on day 1, and capecitabine doses ranging from 850 to 1500 mg m^-2 bid on days 1–7 were explored. Peripheral blood samples were used to genotype 13 SNPs in 10 genes related to drug metabolism or efficacy. Univariate and multivariate Cox analysis was performed to examine associations between SNPs, ORR and PFS.

Results:

The capecitabine RD was 1000 mg m⁻² bid. Diarrhoea and neutropenia were the DLTs. After a median follow-up of 52.5 months, the median PFS and OS were 12 (95% CI; 10.6–13.4) and 27 months (95% CI; 17.2–36.8), respectively.

The GSTP1-G genotype, the Köhne low-risk category and use of a consolidation approach strongly correlated with decreased risk of progression. Patients with all favourable variables showed a median PFS of 42 months vs 3.4 months in the group with all adverse factors. A superior clinical response was obtained in patients with one GSTP1-G allele as compared with GSTP1-AA carriers (P=0.004).

Conclusion:

First-line therapy with oxaliplatin, irinotecan and capecitabine is efficient and well-tolerated. The GSTP1 polymorphism A>G status was significantly associated with ORR and PFS in mCRC treated with this triplet therapy.

Pharmacological targeting of NF-kappaB potentiates the effect of the topoisomerase inhibitor CPT-11 on colon cancer cells

NF-κB interferes with the effect of most anti-cancer drugs through induction of anti-apoptotic genes. Targeting NF-κB is therefore expected to potentiate conventional treatments in adjuvant strategies. Here we used a pharmacological inhibitor of the IKK2 kinase (AS602868) to block NF-κB activation. In human colon cancer cells, inhibition of NF-κB using 10 μM AS602868 induced a 30–50% growth inhibitory effect and strongly enhanced the action of SN-38, the topoisomerase I inhibitor and CPT-11 active metabolite. AS602868 also potentiated the cytotoxic effect of two other antineoplasic drugs: 5-fluorouracil and etoposide. In xenografts experiments, inhibition of NF-κB potentiated the antitumoural effect of CPT-11 in a dose-dependent manner. Eighty-five and 75% decreases in tumour size were observed when mice were treated with, respectively, 20 or 5 mg kg⁻¹ AS602868 associated with 30 mg kg⁻¹ CPT-11 compared to 47% with CPT-11 alone. Ex vivo tumour analyses as well as in vitro studies showed that AS602868 impaired CPT-11-induced NF-κB activation, and enhanced tumour cell cycle arrest and apoptosis. AS602868 also enhanced the apoptotic potential of TNFα on HT-29 cells. This study is the first demonstration that a pharmacological inhibitor of the IKK2 kinase can potentiate the therapeutic efficiency of antineoplasic drugs on solid tumours.

Phase II trial of oxaliplatin/irinotecan/5-fluorouracil/leucovorin for metastatic colorectal cancer

BACKGROUND

Individually, oxaliplatin and irinotecan have substantial activity in metastatic colorectal cancer (CRC) in combination with 5-fluorouracil/leucovorin. A combination regimen using all 4 agents could potentially increase response rates in CRC.

PATIENTS AND METHODS

A multicenter phase II trial of oxaliplatin 85 mg/m(2) on day 1, irinotecan 175 mg/m(2) on day 1, 5-fluorouracil 240 mg/m(2) by 90-minute infusion on days 2-5, and leucovorin 20 mg/m(2) on days 2-5 of a 21-day cycle was undertaken in patients with CRC through the North Central Cancer Treatment Group. The primary endpoint was response rate, with secondary endpoints of toxicity and quality of life.

RESULTS

Of 14 patients enrolled (13 evaluable), 3 partial responses were seen (23%; 95% confidence interval, 5%-54%), and 9 patients had stable disease (69%). Toxicity was significant, with 1 (8%) grade 5 event (diarrhea and dehydration) and 3 (23%) grade 4 events (leukopenia and diarrhea). The study was closed to further enrollment because of toxicity.

CONCLUSION

The 4-drug regimen was extremely toxic. Future studies incorporating irinotecan- and oxaliplatin-based therapy should consider alternative schedules.

Phase III trial of infusional fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) compared with infusional fluorouracil, leucovorin, and irinotecan (FOLFIRI) as first-line treatment for metastatic colorectal cancer: the Gruppo Oncologico Nord Ovest

PURPOSE

The Gruppo Oncologico Nord Ovest (GONO) conducted a phase III study comparing fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI [irinotecan 165 mg/m2 day 1, oxaliplatin 85 mg/m2 day 1, leucovorin 200 mg/m2 day 1, fluorouracil 3,200 mg/m2 48-hour continuous infusion starting on day 1, every 2 weeks]) with infusional fluorouracil, leucovorin, and irinotecan (FOLFIRI).

METHODS

Selection criteria included unresectable metastatic colorectal cancer, age 18 to 75 years, and no prior chemotherapy for advanced disease. The primary end point was response rate (RR).

RESULTS

A total of 244 patients were randomly assigned. An increase of grade 2 to 3 peripheral neurotoxicity (0% v 19%; P < .001), and grade 3 to 4 neutropenia (28% v 50%; P < .001) were observed in the FOLFOXIRI arm. The incidence of febrile neutropenia (3% v 5%) and grade 3 to 4 diarrhea (12% v 20%) were not significantly different. Responses, as assessed by investigators, were, for FOLFIRI and FOLFOXIRI, respectively, complete, 6% and 8%; and partial, 35% and 58%, (RR, 41% v 66%; P = .0002). RR confirmed by an external panel was 34% versus 60% (P < .0001). The R0 secondary resection rate of metastases was greater in the FOLFOXIRI arm (6% v 15%; P = .033, among all 244 patients; and 12% v 36%; P = .017 among patients with liver metastases only). Progression-free survival (PFS) and overall survival (OS) were both significantly improved in the FOLFOXIRI arm (median PFS, 6.9 v 9.8 months; hazard ratio [HR], 0.63; P = .0006; median OS, 16.7 v 22.6 months; HR, 0.70; P = .032).

CONCLUSION

The FOLFOXIRI regimen improves RR, PFS, and OS compared with FOLFIRI, with an increased, but manageable, toxicity in patients with metastatic colorectal cancer with favorable prognostic characteristics. Further studies of FOLFOXIRI in combination with targeted agents and in the neoadjuvant setting are warranted.

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.

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.

Irinotecan, oxaliplatin and raltitrexed for the treatment of advanced colorectal cancer

Out of every 17-18 individuals in the US, one develops colorectal cancer (CRC) in their lifetime. Of individuals diagnosed with CRC, > 50% present or develop metastatic disease, which, if untreated, is associated with 6-9 months median survival. Although surgical resection is the primary treatment modality for CRC, chemotherapy is the mainstay of treatment for metastatic or unresectable disease. For nearly three decades, 5-fluorouracil (5-FU) has been the chemotherapy of choice for treatment of CRC. However, the response rates to single 5-FU therapy have been suboptimal with an objective tumour response of 10-20%. Attempts have been made to improve the efficacy of 5-FU by either schedule alteration (protracted infusion versus intravenous push) or biochemical modulation with leucovorin (LV). Continuous infusion induced more tumour regression and prolonged the time-to-disease progression with some significant impact on survival (11.3 versus 12.1 months; p < 0.04). 5-FU/LV resulted in a significant increase in overall response rates and in the prolongation of disease-free survival in the adjuvant setting, although severe toxicities represent a major clinical problem. The last 10 years have seen the addition of several new agents such as irinotecan, oxaliplatin, raltitrexed, bevacizumab and cetuximab. The prognosis has significantly improved with the addition of these agents, with median survivals now > 20 months. This review paper focuses on irinotecan, oxaliplatin and raltitrexed when used alone and in combination.

Beyond 5-fluorouracil: new horizons in systemic therapy for advanced colorectal cancer

Worldwide, colorectal cancer is a common cancer and a major cause of morbidity and mortality. Patients frequently present with, or later develop, metastatic disease. Median survival with supportive care alone is approximately 6 - 8 months. However, a number of recent developments have greatly increased the range of therapeutic options, improving median survival to > 20 months. Cytotoxic agents such as capecitabine, irinotecan and oxaliplatin are now established treatment strategies. In parallel, an improved understanding of tumour biology has led to the development of non-cytotoxic targeted therapies. Examples include bevacizumab (targeting tumour angiogenesis) and cetuximab (targeting the epidermal growth factor receptor). These agents have recently been incorporated into standard management. This paper reviews these and other advances in the care of patients with advanced colorectal cancer and discusses a number of agents that are currently under development.

Oxaliplatin combined with irinotecan and 5-fluorouracil/leucovorin (OCFL) in metastatic colorectal cancer: a phase I–II study

BACKGROUND

A phase I-II multicenter trial was conducted to define the maximal tolerated dose and describe the activity of an OCFL combination using oxaliplatin (OHP), irinotecan (CPT-11) and 5-fluorouracil (FU)/leucovorin (LV) in metastatic colorectal cancer (CRC).

PATIENTS AND METHODS

CRC patients not pretreated with palliative chemotherapy, with performance status < or =1 and adequate haematological, kidney and liver function, were eligible. Treatment consisted in weekly 24-h infusion 5-FU (2300 mg/m(2))/LV (30 mg) and alternating OHP (70-85 mg/m(2), days 1 and 15) and CPT-11 (80-140 mg/m(2), days 8 and 22) repeated every 5 weeks. OHP and CPT-11 were escalated in cohorts of three to six patients.

RESULTS

Thirty patients received a median of five cycles. Dose-limiting toxicity occurred at dose level 3, and the recommended dose was OHP 70 mg/m(2), CPT-11 100 mg/m(2), LV 30 mg and 5-FU 2300 mg/m(2)/24 h. Grade > or =3 toxicities were diarrhea 23%, neutropenia 20%, fatigue 7%, and neurologic 7%. Two febrile neutropenia episodes (one fatal) were recorded. Among 28 patients with measurable disease (90%), we observed two complete and 20 partial responses; overall RR was 78% (95% CI, 59% to 92%). Median time to progression and overall survival were 9.5 and 25.4 months, respectively. Seven patients underwent liver metastases resection.

CONCLUSION

OCFL is an overall well tolerated regimen with very high efficacy, which makes it most suitable for tumour control before surgery of metastatic 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.

Enhanced chemosensitivity to irinotecan by RNA interference-mediated down-regulation of the nuclear factor-kappaB p65 subunit

In preclinical tumor models, inhibition of nuclear factor-kappaB (NF-kappaB) has been associated with increased sensitivity to chemotherapeutic agents such as irinotecan (CPT-11). This is based on the fact that a variety of chemotherapy agents such as CPT-11 activate NF-kappaB to result in the expression of genes such as c-IAP1 and c-IAP2 that might be responsible for the inhibition of chemotherapy-induced apoptosis. In this study, RNA interference [small interfering RNA (siRNA)] was used to down-regulate the NF-kappaB p65 subunit in the HCT116 colon cancer cell line, and its role, in the presence and absence of CPT-11, was assessed on cell growth and apoptosis. Reduction of endogenous p65 by siRNA treatment significantly impaired CPT-11-mediated NF-kappaB activation, enhanced apoptosis, and reduced colony formation in soft agar. Furthermore, the in vivo administration of p65 siRNA reduced HCT116 tumor formation in xenograft models in the presence but not the absence of CPT-11 administration. These data indicate that the administration of siRNA directed against the p65 subunit of NF-kappaB can effectively enhance in vitro and in vivo sensitivity to chemotherapeutic agents.

Combination of 5-fluorouracil and N1,N11-diethylnorspermine markedly activates spermidine/spermine N1-acetyltransferase expression, depletes polyamines, and synergistically induces apoptosis in colon carcinoma cells

The thymidylate synthase inhibitor 5-fluorouracil (5-FU) is used widely for chemotherapy of colorectal carcinoma. Recent studies showed that 5-FU affects polyamine metabolism in colon carcinoma cells. We therefore examined whether combinations of 5-FU with drugs that specifically target polyamine metabolism, i.e. N1,N11-diethylnorspermine (DENSPM) or alpha-difluoromethylornithine (DFMO), have synergistic effects in killing HCT116 colon carcinoma cells with wild-type or absent p53. Our results showed that simultaneous 5-FU and DENSPM, a spermine analogue, synergistically increased transcript levels of the polyamine catabolism enzyme spermidine/spermine N1-acetyltransferase, depleted spermine and spermidine, increased acetylated spermidine, and produced synergistic tumor cell apoptosis in both p53 wild-type and p53-null variants. By contrast, simultaneous combination of 5-FU with DFMO, an inhibitor of the polyamine biosynthetic enzyme ornithine decarboxylase, depleted putrescine but did not produce synergistic cell killing. Some pre-treatment and post-treatment regimens of DENSPM and DFMO were antagonistic to 5-FU depending on cellular p53 status. Protein and transcriptome expression analysis showed that combined 5-FU and DENSPM treatment activated caspase 9, but not caspase 3, and significantly suppressed NADH dehydrogenases and cytochrome c oxidases, consistent with the observed increase in hydrogen peroxide, loss of mitochondrial membrane potential, and release of cytochrome c. Our findings demonstrate the importance of the polyamine pathway in 5-FU effects and suggest that the combination of 5-FU with DENSPM has potential for development as therapy for colorectal carcinoma.

New systemic frontline treatment for metastatic colorectal carcinoma

Options for first-line chemotherapy in patients with metastatic colorectal carcinoma have broadened considerably with the introduction of irinotecan and oxaliplatin. Furthermore, the oral fluoropyrimidine capecitabine has demonstrated efficacy in Phase III trials and recently was approved for first-line treatment in Europe and the United States. Capecitabine yielded similar median times to disease progression and median survival rates compared with bolus 5-fluorouracil (5-FU)/leucovorin (LV) (Mayo Clinic/North Central Cancer Treatment Group regimen), with superior and similar response rates, respectively. However, its role as a first-line, single-agent substitute for intermittent infusional 5-FU/LV remains to be defined. The addition of irinotecan or oxaliplatin to 5-FU/LV resulted in improved response rates and progression-free survival in large, randomized trials; moreover, irinotecan-containing regimens resulted in improved overall survival. Prevalent regimens of irinotecan/5-FU/LV and oxaliplatin/5-FU/LV have been compared in two randomized Phase III trials. One study demonstrated the statistical superiority of oxaliplatin/infusional 5-FU/LV over irinotecan/bolus 5-FU/LV in terms of response, time to disease progression, and median survival; however, those advantages may have been attributable to infusional administration or to major differences in second-line therapy. A randomized Phase III study comparing irinotecan and oxaliplatin in combination with the same infusional 5-FU/LV regimens and crossover in case of disease progression showed equivalent efficacy for both schedules in the first-line setting, but the irinotecan combination proved beneficial in terms of safety. New molecular targeted agents, such as angiogenesis-modulating compounds (e.g., bevacizumab) and epidermal growth factor receptor inhibitors (e.g., cetuximab), are under clinical investigation. This review updates current systemic frontline treatments and future perspectives for patients with advanced colorectal carcinoma.

Oxaliplatin: a review of its use in combination therapy for advanced metastatic colorectal cancer

Oxaliplatin (Eloxatin) is the only platinum compound to show clinical activity in colorectal cancer. The efficacy of a combination of oxaliplatin with various schedules of fluorouracil (5-FU)/folinic acid (FA) as first- or second-line treatment for advanced metastatic colorectal cancer has been investigated in large phase III trials. FOLFOX4 (an oxaliplatin/5-FU/FA regimen) as first-line therapy (n = 795) was superior to irinotecan/5-FU/FA (IFL). Response rates were 45% vs 31%, and median progression-free survival duration was 8.7 vs 6.9 months. The survival advantage shown by FOLFOX4 over the irinotecan combination (median survival duration 19.5 vs 14.8 months) may be confounded by differences in post-study treatment but equivalent efficacy is supported by another phase III trial of oxaliplatin and irinotecan combinations. As first-line therapy, oxaliplatin added to various 5-FU/FA regimens more than doubled the response rates from 16-22.6% to 48.3-53% and the median duration of progression-free survival was significantly longer with oxaliplatin/5-FU/FA than 5-FU/FA alone (7.9-9 versus 5.3-6.2 months, respectively). In disease resistant to irinotecan-based therapies, the oxaliplatin (FOLFOX4) regimen had superior efficacy to 5-FU/FA alone in a pivotal phase III trial (n = 816). Response rates and median durations of progression-free survival were 9.6% vs 0.7% and 5.6 vs 2.6 months, respectively. An oxaliplatin-induced cumulative peripheral sensory neuropathy (evident when total dose reaches approximate, equals 800 mg/m(2)) is dose limiting. The most frequently occurring grade 3 or 4 toxicities in oxaliplatin/5-FU/FA-recipients were neutropenia (up to 48%) and neurological toxicities (up to 18%). Gastrointestinal effects (diarrhoea [ approximate, equals 12%], nausea, vomiting, or mucositis/stomatitis [up to 6%]) are manageable. Withdrawals from oxaliplatin treatment were due to neuropathy (up to 10%), diarrhoea and/or vomiting (1%) or cutaneous toxicity (1%).

CONCLUSION

As first-line therapy for metastatic colorectal cancer, oxaliplatin with 5-FU/FA consistently improves response rates and progression-free survival compared with various regimens of 5-FU/FA alone. The significant survival advantage shown by oxaliplatin/5-FU/FA (FOLFOX4) compared with first-line therapy with irinotecan/5-FU/FA (IFL) is encouraging but may require further confirmation. Oxaliplatin/5-FU/FA produces a significantly higher response rate and longer progression-free survival than 5-FU/FA in patients failing irinotecan-based therapies, and as such is also a useful second-line treatment. Although cumulative neurotoxicity is dose limiting, oxaliplatin has a manageable tolerability profile. Oxaliplatin as first- or second-line therapy is a valuable addition to the limited, but expanding, armamentarium of cytotoxic agents useful in advanced metastatic colorectal cancer.