Leucovorin and Fluorouracil With or Without Oxaliplatin as First-Line Treatment in Advanced Colorectal Cancer

PURPOSE

In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point.

PATIENTS AND METHODS

Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m2/d) followed by a 5FU bolus (400 mg/m2/d) and 22-hour infusion (600 mg/m2/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m2 as a 2-hour infusion on day 1.

RESULTS

Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P = .0003) and better response rate (50.7% v 22.3%; P = .0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P = .12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41.7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment (P = .004).

CONCLUSION

The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.

Improving the spectral resolution in fluorescence microscopy through shaped-excitation imaging

The visualization of distinct molecular species represents an important challenge of bio-imaging research. In past decades, the development of multicolor fluorescent (FL) labels has greatly improved our ability to track biological analytes, paving the way for important advances in understanding the cell dynamics. It remains challenging, however, to visualize a large number of different fluorephores simultaneously. Owing to a spectrally broad absorption of fluorescent dyes, only up to five color categories can be resolved at once. Here, we demonstrate a general strategy for distinguishing between multiple fluorescent targets in acquired microscopy images with improved accuracy. The present strategy is enabled through spectral shaping of the excitation light with an optical filter that uniquely attenuates the light absorption of each fluorophore in the investigated sample. The resulting emission changes, induced by such excitation modulation, are therefore target-specific and can be used for identifying various fluorescent species. The technique is demonstrated through an accurate identification of 8 different CdSe dyes with absorption maxima spanning the 520-620 spectral range. It is subsequently applied for accurate measurements of the pH balance in buffers emulating a metabolism of tumor cells.

Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long‐standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co‐infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis‐specific Th1 immune response. We hypothesized that these changes in co‐infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co‐infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte‐derived macrophages (MDM) from F. hepatica‐infected cattle which is associated with suppression of pro‐inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica‐infected cattle is increased. These findings reflecting the bystander effect of helminth‐induced downregulation of pro‐inflammatory responses provide insights to understand host‐pathogen interactions in co‐infection.

The value of using schools as community assets for health

In planning, designing, procuring and ensuring delivery of improved services ('commissioning') for the school age population, the outcomes should be students who are healthy to learn and who learn to be healthy. Intuitively, linking education and health development together within the wider learning environment seems a good start to planning school health. However there has been a shortage of either theoretical models that can span different settings or experimental research that demonstrates improved community health. Is there evidence that the wider learning environment provided in a school is valuable in improving health? An initial scoping exercise identified domains of health where there was a promise of health gain. International literature on school health outcomes using the framework of Asset-Based Community Development (ABCD) has been reviewed. It was found that research on a variety of interventions was relevant to schools as an asset for public health. Effective areas for health gain were identified for local planning and evaluation using this community model. However, none of the studies reviewed was originally designed to test schools as assets and most of the research lacked methodological rigour, especially regarding children in low income countries. The ABCD model could help national governments develop resources for both education and health, but there is a global need to generate better quality evidence. Then people who commission for their local communities can make more effective use of these multifaceted assets to improve health and education outcomes for children.

Final results from PRIME: randomized phase III study of panitumumab with FOLFOX4 for first-line treatment of metastatic colorectal cancer

BACKGROUND

The Panitumumab Randomized trial In combination with chemotherapy for Metastatic colorectal cancer to determine Efficacy (PRIME) demonstrated that panitumumab-FOLFOX4 significantly improved progression-free survival (PFS) versus FOLFOX4 as first-line treatment of wild-type (WT) KRAS metastatic colorectal cancer (mCRC), the primary end point of the study.

PATIENTS AND METHODS

Patients were randomized 1:1 to panitumumab 6.0 mg/kg every 2 weeks + FOLFOX4 (arm 1) or FOLFOX4 (arm 2). This prespecified final descriptive analysis of efficacy and safety was planned for 30 months after the last patient was enrolled.

RESULTS

A total of 1183 patients were randomized. Median PFS for WT KRAS mCRC was 10.0 months [95% confidence interval (CI) 9.3-11.4 months] for arm 1 and 8.6 months (95% CI 7.5-9.5 months) for arm 2; hazard ratio (HR) = 0.80; 95% CI 0.67-0.95; P = 0.01. Median overall survival (OS) for WT KRAS mCRC was 23.9 months (95% CI 20.3-27.7 months) for arm 1 and 19.7 months (95% CI 17.6-22.7 months) for arm 2; HR = 0.88; 95% CI 0.73-1.06; P = 0.17 (68% OS events). An exploratory analysis of updated survival (>80% OS events) was carried out which demonstrated improvement in OS; HR = 0.83; 95% CI 0.70-0.98; P = 0.03 for WT KRAS mCRC. The adverse event profile was consistent with the primary analysis.

CONCLUSIONS

In WT KRAS mCRC, PFS was improved, objective response was higher, and there was a trend toward improved OS with panitumumab-FOLFOX4, with significant improvement in OS observed in an updated analysis of survival in patients with WT KRAS mCRC treated with panitumumab + FOLFOX4 versus FOLFOX4 alone (P = 0.03). These data support a positive benefit-risk profile for panitumumab-FOLFOX4 for patients with previously untreated WT KRAS mCRC. KRAS testing is critical to select appropriate patients for treatment with panitumumab.

Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4(2-) ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing bioreactors. The sulfide was measured using a sulfide ion selective electrode (pS) and the values obtained were used to calculate proportional-integral-derivative (PID) controller parameters. The experiments were performed in an inverse fluidized bed bioreactor with automated operation using the LabVIEW software version 2009(®). A rapid response and high sulfide increment was obtained through a stepwise increase in the CODin concentration, while a stepwise decrease to the HRT exhibited a slower response with smaller sulfide increment. Irrespective of the way the OLR was decreased, the pS response showed a time-varying behavior due to sulfide accumulation (HRT change) or utilization of substrate sources that were not accounted for (CODin change). The pS electrode response, however, showed to be informative for applications in sulfate reducing bioreactors. Nevertheless, the recorded pS values need to be corrected for pH variations and high sulfide concentrations (>200 mg/L).

Capecitabine versus 5-fluorouracil/folinic acid as adjuvant therapy for stage III colon cancer: final results from the X-ACT trial with analysis by age and preliminary evidence of a pharmacodynamic marker of efficacy

BACKGROUND

This multicenter randomized trial compared oral capecitabine with bolus i.v. 5-fluorouracil (5-FU)/folinic acid (FA) as adjuvant therapy for stage III colon cancer.

PATIENTS AND METHODS

Patients were assigned to 24 weeks of capecitabine 1250 mg/m(2) twice daily on days 1-14 every 3 weeks or 5-FU/FA (Mayo Clinic regimen). The primary end point was disease-free survival (DFS).

RESULTS

The intent-to-treat population received capecitabine (n = 1004) or 5-FU/FA (n = 983). With a median follow-up of 6.9 years, capecitabine was at least equivalent to 5-FU/FA in terms of DFS [hazard ratio (HR) = 0.88; 95% confidence interval (CI) 0.77-1.01] and overall survival (OS) (HR = 0.86; 95% CI 0.74-1.01); the 95% CI upper limits were significantly less than the predefined noninferiority margins of 1.20 (P < 0.0001) and 1.14 (P < 0.001), respectively. This pattern was maintained in all subgroups, including patients aged ≥ 70 years. Preplanned multivariate analyses showed that capecitabine had statistically significant beneficial effects on DFS (P = 0.021) and OS (P = 0.020) versus 5-FU/FA. A post hoc analysis suggested that the occurrence of hand-foot syndrome may be associated with better outcomes in capecitabine recipients.

CONCLUSION

Oral capecitabine is an effective alternative to bolus 5-FU/FA as adjuvant treatment of patients with stage III colon cancer with efficacy benefits maintained at 5 years and in older patients.

A phase 1 trial of recombinant human IL-21 in combination with cetuximab in patients with metastatic colorectal cancer

BACKGROUND

Pre-clinical data indicate enhanced anti-tumour activity when combining recombinant human interleukin-21 (rIL-21), a class 1 cytokine, with cetuximab, a monoclonal antibody, targeting the epidermal growth factor receptor. This phase 1 trial assessed the safety and tolerability of escalating doses of rIL-21 in combination with cetuximab in chemo-naïve patients with stage IV colorectal cancer.

PATIENTS AND METHODS

Sequential cohorts of PS 0-1, asymptomatic patients, were treated weekly with cetuximab 250 mg m(-2) intravenously (i.v.) plus escalating i.v. doses of rIL-21 following an initial loading dose of cetuximab 400 mg m(-2). Initial treatment period was 8 weeks, with extension permitted in patients without disease progression.

RESULTS

In all, 15 patients were included in this study. Adverse events related to rIL-21 or rIL-21 plus cetuximab included lethargy, nausea/vomiting, stomatitis, lymphopenia and pyrexia and were mainly ≤ grade 2. One dose limiting toxicity occurred (grade 3 diarrhoea). Maximum tolerated dose was not determined because of the premature study closure. Maximum administered dose was 100 μg kg(-1) rIL-21 weekly. In all, 60% of the patients had stable disease. Immune activation was confirmed by various T- and NK-cell activation biomarkers, including dose-dependent increases in serum sCD25.

CONCLUSION

rIL-21 weekly combined with cetuximab is well tolerated at doses up to 100 μg kg(-1) and results in activation of immune response biomarkers.

Bevacizumab is equally effective and no more toxic in elderly patients with advanced colorectal cancer: a subgroup analysis from the AGITG MAX trial: an international randomised controlled trial of Capecitabine, Bevacizumab and Mitomycin C

BACKGROUND

In an ageing population, a greater proportion of geriatric patients will be considered for systemic chemotherapy. Colorectal cancer (CRC) is a common malignancy and will be a major health issue in geriatrics. We used the MAX population to investigate whether age affected the improved outcome found in CRC when bevacizumab is added to capecitabine chemotherapy.

PATIENTS AND METHODS

MAX, a three arm study of Capecitabine (C) versus CBevacizumab (CB) versus CBMitomycin C (CBM), found an improvement in progression-free survival (PFS), with addition of B [+/- mitomycin C (MMC)] to C. This analysis assesses the effect of adding B (+/- MMC) to C on PFS, overall survival (OS), response rate (RR), toxicity and dose intensity in geriatric patients (age ≥ 75 years).

RESULTS

Ninety-nine patients (21%) were aged 75-86 years. Baseline characteristics were well balanced. Eighty-eight per cent commenced C at the lower optional dose of 2000 mg/m(2)/day; days 1-14, q21 (61% for <75 years) and 88% were Eastern Cooperative Oncology Group 0-1. Co-morbidities were as expected in this population. The addition of B significantly improved PFS in geriatric patients(C 5.8 months versus CB 8.8 months, Hazard ratio (HR) 0.65 and C versus CBM 10.4 months HR 0.38). The interaction test for OS, RR and PFS revealed no impact of age. Dose intensity was maintained >90% in all patients. There were no major differences in toxicity patterns between age cohorts.

CONCLUSIONS

Addition of B to C significantly improved PFS in this geriatric population, with similar benefits to those aged <75 years. Treatment was well tolerated with no signal of increased toxicity (including thromboembolism) when compared with those aged <75 years.

Use of capecitabine in management of early colon cancer

Capecitabine (Xeloda^®, Roche, Basel, Switzerland) is a pro-drug of 5-fluorouracil (5-FU), and it is converted to 5-FU in the cancer cell by enzymatic degradation. The role of capecitabine in colorectal cancer has evolved in the last 15 years. In early trials in the metastatic setting, capecitabine has shown superior response rates compared with those achieved with 5-FU (Mayo Clinic regimen) (26% vs 17%), with equivalent progression-free survival and overall survival. In the adjuvant setting, the Xeloda in Adjuvant Colon Cancer Therapy (X-ACT) trial demonstrated that capecitabine as a single agent led to improvement in relapse-free survival (hazard ratio: 0.86, 95% confidence interval: 0.74–0.99, P = 0.04) and was associated with significantly fewer adverse events than 5-FU plus leucovorin (LV, folinic acid). On the basis of the X-ACT trial, capecitabine was approved by the United States Food and Drug Administration, the National Institute for Clinical Excellence, and the Scottish Medicines Consortium as monotherapy for the adjuvant treatment of stage III colon cancer. The next step was to incorporate capecitabine into combination therapy. The XELOXA trial studied the combination of capecitabine and oxaliplatin (XELOX) vs 5-FU/LV and demonstrated 5-year disease-free survival of 66% for XELOX, compared with 60% for 5-FU/LV. The toxicity profile was also quite comparable in the two arms. So both the single agent use of capecitabine as well as in combination with oxaliplatin can be considered as part of the standard of care in management of early colon cancer in appropriately selected patient groups.

XELOX vs FOLFOX-4 as first-line therapy for metastatic colorectal cancer: NO16966 updated results

Background:

We report updated overall survival (OS) data from study NO16966, which compared capecitabine plus oxaliplatin (XELOX) vs 5-fluorouracil/folinic acid plus oxaliplatin (FOLFOX4) as first-line therapy in metastatic colorectal cancer.

Methods:

NO16966 was a randomised, two-arm, non-inferiority, phase III comparison of XELOX vs FOLFOX4, which was subsequently amended to a 2 × 2 factorial design with further randomisation to bevacizumab or placebo. A planned follow-up exploratory analysis of OS was performed.

Results:

The intent-to-treat (ITT) population comprised 2034 patients (two-arm portion, n=634; 2 × 2 factorial portion, n=1400). For the whole NO16966 study population, median OS was 19.8 months in the pooled XELOX/XELOX-placebo/XELOX-bevacizumab arms vs 19.5 months in the pooled FOLFOX4/FOLFOX4-placebo/FOLFOX4-bevacizumab arms (hazard ratio 0.95 (97.5% CI 0.85–1.06)). In the pooled XELOX/XELOX-placebo arms, median OS was 19.0 vs 18.9 months in the pooled FOLFOX4/FOLFOX4-placebo arms (hazard ratio 0.95 (97.5% CI 0.83–1.09)). FOLFOX4 was associated with more grade 3/4 neutropenia/granulocytopenia and febrile neutropenia than XELOX, and XELOX with more grade 3 diarrhoea and grade 3 hand-foot syndrome than FOLFOX4.

Conclusion:

Updated survival data from study NO16966 show that XELOX is similar to FOLFOX4, confirming the primary analysis of progression-free survival. XELOX can be considered as a routine first-line treatment option for patients with metastatic colorectal cancer.

Disulfiram modulated ROS-MAPK and NFκB pathways and targeted breast cancer cells with cancer stem cell-like properties

Background:

Previous studies indicate that disulfiram (DS), an anti-alcoholism drug, is cytotoxic to cancer cell lines and reverses anticancer drug resistance. Cancer stem cells (CSCs) are the major cause of chemoresistance leading to the failure of cancer chemotherapy. This study intended to examine the effect of DS on breast cancer stem cells (BCSCs).

Methods:

The effect of DS on BC cell lines and BCSCs was determined by MTT, western blot, CSCs culture and CSCs marker analysis.

Results:

Disulfiram was highly toxic to BC cell lines in vitro in a copper (Cu)-dependent manner. In Cu-containing medium (1 μM), the IC₅₀ concentrations of DS in BC cell lines were 200–500 nM. Disulfiram/copper significantly enhanced (3.7–15.5-fold) cytotoxicity of paclitaxel (PAC). Combination index isobologram analysis demonstrated a synergistic effect between DS/Cu and PAC. The increased Bax and Bcl2 protein expression ratio indicated that intrinsic apoptotic pathway may be involved in DS/Cu-induced apoptosis. Clonogenic assay showed DS/Cu-inhibited clonogenicity of BC cells. Mammosphere formation and the ALDH1^+VE and CD24^Low/CD44^High CSCs population in mammospheres were significantly inhibited by exposure to DS/Cu for 24 h. Disulfiram/copper induced reactive oxygen species (ROS) generation and activated its downstream apoptosis-related cJun N-terminal kinase and p38 MAPK pathways. Meanwhile, the constitutive NFκB activity in BC cell lines was inhibited by DS/Cu.

Conclusion:

Disulfiram/copper inhibited BCSCs and enhanced cytotoxicity of PAC in BC cell lines. This may be caused by simultaneous induction of ROS and inhibition of NFκB.

Efficacy of capecitabine versus 5-fluorouracil in colorectal and gastric cancers: a meta-analysis of individual data from 6171 patients

BACKGROUND

To compare the effects of oral capecitabine-containing chemotherapy regimens with i.v. 5-fluorouracil (5-FU)-containing chemotherapy regimens on overall survival in patients with gastrointestinal cancers.

METHODS

A meta-analysis, based on individual patient data from six randomised non-inferiority trials, was carried out at the request of regulatory authorities to compare the effects of single-agent capecitabine or capecitabine-containing chemotherapy versus matched 5-FU-based regimens in terms of overall survival in patients with stage III colon, metastatic colorectal or advanced gastric cancer.

RESULTS

Data from a total of 6171 patients with stage III colon cancer (n = 1987), metastatic colorectal cancer (n = 3868) or advanced gastric cancer (n = 316) were included. A total of 3097 patients were treated with capecitabine-containing chemotherapy and 3074 patients with 5-FU-containing chemotherapy. The unadjusted hazard ratio for overall survival for capecitabine-containing chemotherapy versus 5-FU-containing chemotherapy was 0.94 (95% confidence interval 0.89-1.00; P = 0.0489).

CONCLUSIONS

Oral capecitabine is at least equivalent to i.v. 5-FU in terms of overall survival in patients with gastrointestinal cancers. Capecitabine and 5-FU can be used interchangeably in these patient populations.

Review of completed and ongoing trials of capecitabine-based adjuvant therapy in patients with early-stage colon cancer

495

Background: Capecitabine is an established alternative to 5-FU in gastrointestinal cancers. In metastatic colorectal cancer, capecitabine is non-inferior to 5-FU and capecitabine + oxaliplatin (XELOX) is non-inferior to FOLFOX4. Capecitabine is also an effective adjuvant treatment for early-stage colon cancer. Here we review the evidence available from completed studies of adjuvant capecitabine and describe ongoing trials in this setting.

Methods: The X-ACT trial included 1,987 patients (pts) with resected stage III disease receiving either capecitabine (n=1,004) or bolus 5-FU/LV (n=983). NO16968 included 1,886 pts with resected stage III disease receiving either XELOX (n=944) or 5-FU/LV (n=942). The primary efficacy endpoint of both trials was DFS. Other large phase III trials of capecitabine in high-risk stage II/stage III pts include AVANT (XELOX + bevacizumab vs. FOLFOX4 ± bevacizumab), QUASAR2 (capecitabine vs. capecitabine + bevacizumab), SCOT (capecitabine or 5-FU/LV + oxaliplatin 12w vs. 24w), and a Japanese study of single-agent capecitabine.

Results: In X- ACT, capecitabine was at least equivalent to 5-FU/LV in terms of DFS (HR=0.88; 95% CI, 0.77–1.01) and OS (HR=0.86; 95% CI, 0.74–1.01). In a preplanned multivariate analysis, capecitabine led to significantly superior DFS (p=0.02) and OS (p=0.02) vs. bolus 5-FU/LV [Twelves et al. WCGIC 2010]. In NO16968, DFS was significantly superior for XELOX vs. 5-FU/LV (HR=0.80; 95% CI, 0.69–0.93; p=0.0045) [Haller et al. ECCO-ESMO 2009]. There was a trend towards improvement in OS with XELOX (HR=0.87; 95% CI, 0.72–1.05; p=0.1486); follow-up is ongoing. Capecitabine-based therapy had an acceptable safety profile in both trials [Twelves et al. NEJM 2005; Schmoll et al. JCO 2007]. Data have yet to be reported from the AVANT, QUASAR2, SCOT and Japanese trials, although results from these trials in over 15,000 pts are awaited with interest.

Conclusions: Adjuvant capecitabine is non-inferior to 5-FU/LV when given as monotherapy and superior to 5-FU/LV when given in combination with oxaliplatin. Capecitabine should be considered as a standard component of adjuvant treatment regimens for pts with stage III disease.

[Table: see text]

Comparative clinical efficacy of adjuvant chemotherapy regimens in randomized controlled trials (RCTs) of early-stage colon cancer: Systematic review and meta-analysis

498

Background: A systematic review was conducted to identify RCTs of adjuvant chemotherapy regimens for early-stage colon cancer and a network meta-analysis performed to compare efficacy of oxaliplatin/fluoropyrimidine regimens.

Methods: A systematic review identified RCTs recruiting adult patients with early-stage (adjuvant) stage II/III colon cancer. Outcome measures included hazard ratios for DFS and OS. Only publications in English were considered. Study quality was assessed using the Cochrane Collaboration “risk of bias” assessment tool. A single reviewer screened abstracts/titles using predefined selection criteria, with critical appraisal and data extraction conducted independently by two reviewers. A Bayesian network meta-analysis was used to estimate comparative efficacy of adjuvant chemotherapy across RCTs.

Results: 56 articles describing 40 trials were selected, of which six reported data on regimens accepted as current standard of care (capecitabine/X-ACT, XELOX/NO16968, FOLFOX/MOSAIC, FLOX/C-07) or common comparators: bolus 5FU/LV and LV5FU2 (C-96-1, PETACC-2). Statistical assessment of heterogeneity was not possible due to the limited study network. Baseline characteristics were similar across trials with the exception of three trials recruiting only stage III patients; sub-group analysis on these trials was not possible due to lack of common comparators. There was no significant difference in DFS at a median follow-up of 3-years (or closest reported analysis) for XELOX vs. FLOX (HR=0.99, 95% CI 0.80–1.22) or FOLFOX (HR=1.00, 95% CI 0.72–1.41). There was also no significant difference in OS at a median follow-up of at least 5 years. Taken as a class, oxaliplatin-containing regimens (XELOX, FOLFOX, FLOX) improved DFS vs. non-oxaliplatin-containing regimens (HR=0.80, 95% CI 0.73–0.87). This result was confirmed for OS.

Conclusions: Despite the limited number of available trials, the results of these analyses demonstrate a clear benefit of incorporating oxaliplatin into combination regimens for early-stage colon cancer. XELOX, FOLFOX and FLOX appear to be equivalent in terms of efficacy in this setting.

[Table: see text]

Effective management of patients receiving XELOX: Evaluation of impact of dose modifications on outcome in patients from the NO16966, NO16967, and NO16968 trials

497

Background: In patients (pts) with metastatic colorectal cancer (MCRC), XELOX is non-inferior to FOLFOX4 in terms of PFS and OS as either first-line (NO16966, Cassidy et al. JCO 2008) or second-line therapy (NO16967, Rothenberg et al. Ann Oncol 2008). In pts with stage III colon cancer (NO16968, Haller et al. ECCO-ESMO 2009), adjuvant XELOX is superior to 5-FU/LV in terms of DFS. While XELOX is generally well tolerated, regional differences in fluoropyrimidine tolerability were noted in a pooled analysis [Rothenberg et al. ASCO GI 2008], leading to use of lower than recommended doses of capecitabine (i.e. 1,000mg/m2 bid d1–15 with oxaliplatin 130mg/m2 d1 q3w) in some countries.

Methods: NO16966, NO16967 and NO16968 protocols included standard dose/schedule modifications for capecitabine, 5-FU and oxaliplatin for treatment-related adverse events (AEs). Safety parameters included AEs, deaths, laboratory parameters, exposure to trial medication, and withdrawals. In NO16966 and NO16967, Kaplan-Meier curves for PFS were developed for pts with no treatment modifications, and pts with dose reductions, treatment interruptions or cycle delays to assess the effect of treatment modifications on efficacy. NO16968 also included a planned analysis of the effect of dose modifications on DFS.

Results: NO16966 included 1335 pts with previously untreated MCRC receiving XELOX or FOLFOX4. NO16967 included 627 pts with previously treated MCRC receiving XELOX or FOLFOX4. NO16968 included 1886 pts with resected stage III disease receiving XELOX or 5-FU/LV; dose modifications were required for capecitabine in 65% and oxaliplatin in 62% of pts in NO16968. Kaplan-Meier curves of PFS (NO16966/NO16967) or DFS (NO16968) for pts who did and did not require dose modifications indicated that the efficacy of XELOX did not appear to be compromised by dose modifications. Indeed, pts who required dose modifications seemed to have a favourable outcome compared with those who did not.

Conclusions: From these data we cannot make a recommendation that initial dosing should be lower than the labeled dose. However, it is clear that dose modification does not seem to impact patient outcome.

[Table: see text]

Two or three year disease-free survival (DFS) as a primary end-point in stage III adjuvant colon cancer trials with fluoropyrimidines with or without oxaliplatin or irinotecan: data from 12,676 patients from MOSAIC, X-ACT, PETACC-3, C-06, C-07 and C89803

BACKGROUND

The ACCENT group previously established disease-free survival (DFS) with 2 or 3 years median follow-up to predict 5 year overall survival (5 year OS) in stage II and III colon cancer. ACCENT further proposed (1) a stronger association between DFS and OS in stage III than II, and (2) 6 or 7 years necessary to demonstrate DFS/OS surrogacy in recent trials. The relationship between end-points in trials with oral fluoropyrimidines, oxaliplatin and irinotecan is unknown.

METHODS

Associations between the treatment effect hazard ratios (HRs) on 2 and 3 years DFS, and 5 and 6 years OS were examined in 6 phase III trials not included in prior analyses from 1997 to 2002. Individual data for 12,676 patients were analysed; two trials each tested oxaliplatin, irinotecan and oral treatment versus 5-FU/LV.

FINDINGS

Overall association between 2/3 year DFS and 5/6 year OS HRs was modest to poor (simple R² measures: 0.58-0.76, model-based R²: 0.17-0.49). In stage III patients, the association increased (model-based R² ≥ 0.79). Observed treatment effects on 2 year DFS accurately 5/6 year OS effects overall and in stage III patients.

INTERPRETATION

In recent trials of cytotoxic chemotherapy, 2 or 3 years DFS HRs are highly predictive of 5 and 6 years OS HRs in stage III but not stage II patients. In all patients the DFS/OS association is stronger for 6 year OS, thus at least 6 year follow-up is recommended to assess OS benefit. These data support DFS as the primary end-point for stage III colon cancer trials testing cytotoxic agents.