Matthew T. Seymour

Addition of cetuximab to oxaliplatin-based first-line combination chemotherapy for treatment of advanced colorectal cancer: results of the randomised phase 3 MRC COIN trial

Summary Background In the Medical Research Council (MRC) COIN trial, the epidermal growth factor receptor (EGFR)-targeted antibody cetuximab was added to standard chemotherapy in first-line treatment of advanced colorectal cancer with the aim of assessing effect on overall survival. Methods In this randomised controlled trial, patients who were fit for but had not received previous chemotherapy for advanced colorectal cancer were randomly assigned to oxaliplatin and fluoropyrimidine chemotherapy (arm A), the same combination plus cetuximab (arm B), or intermittent chemotherapy (arm C). The choice of fluoropyrimidine therapy (capecitabine or infused fluouroracil plus leucovorin) was decided before randomisation. Randomisation was done centrally (via telephone) by the MRC Clinical Trials Unit using minimisation. Treatment allocation was not masked. The comparison of arms A and C is described in a companion paper. Here, we present the comparison of arm A and B, for which the primary outcome was overall survival in patients with KRAS wild-type tumours. Analysis was by intention to treat. Further analyses with respect to NRAS, BRAF, and EGFR status were done. The trial is registered, ISRCTN27286448. Findings 1630 patients were randomly assigned to treatment groups (815 to standard therapy and 815 to addition of cetuximab). Tumour samples from 1316 (81%) patients were used for somatic molecular analyses; 565 (43%) had KRAS mutations. In patients with KRAS wild-type tumours (arm A, n=367; arm B, n=362), overall survival did not differ between treatment groups (median survival 17·9 months [IQR 10·3–29·2] in the control group vs 17·0 months [9·4–30·1] in the cetuximab group; HR 1·04, 95% CI 0·87–1·23, p=0·67). Similarly, there was no effect on progression-free survival (8·6 months [IQR 5·0–12·5] in the control group vs 8·6 months [5·1–13·8] in the cetuximab group; HR 0·96, 0·82–1·12, p=0·60). Overall response rate increased from 57% (n=209) with chemotherapy alone to 64% (n=232) with addition of cetuximab (p=0·049). Grade 3 and higher skin and gastrointestinal toxic effects were increased with cetuximab (14 vs 114 and 67 vs 97 patients in the control group vs the cetuximab group with KRAS wild-type tumours, respectively). Overall survival differs by somatic mutation status irrespective of treatment received: BRAF mutant, 8·8 months (IQR 4·5–27·4); KRAS mutant, 14·4 months (8·5–24·0); all wild-type, 20·1 months (11·5–31·7). Interpretation This trial has not confirmed a benefit of addition of cetuximab to oxaliplatin-based chemotherapy in first-line treatment of patients with advanced colorectal cancer. Cetuximab increases response rate, with no evidence of benefit in progression-free or overall survival in KRAS wild-type patients or even in patients selected by additional mutational analysis of their tumours. The use of cetuximab in combination with oxaliplatin and capecitabine in first-line chemotherapy in patients with widespread metastases cannot be recommended. Funding Cancer Research UK, Cancer Research Wales, UK Medical Research Council, Merck KGgA.

Different strategies of sequential and combination chemotherapy for patients with poor prognosis advanced colorectal cancer (MRC FOCUS): a randomised controlled trial

BACKGROUND In the non-curative setting, the sequence in which anticancer agents are used, singly or in combination, may be important if patients are to receive the maximum period of disease control with the minimum of adverse effects. We compared sequential and combination chemotherapy strategies in patients with unpretreated advanced or metastatic colorectal cancer, who were regarded as not potentially curable irrespective of response. METHODS We studied patients with advanced colorectal cancer, starting treatment with non-curative intent. 2135 unpretreated patients were randomly assigned to three treatment strategies in the ratio 1:1:1. Strategy A (control group) was single-agent fluorouracil (given with levofolinate over 48 h every 2 weeks) until failure, then single-agent irinotecan. Strategy B was fluorouracil until failure, then combination chemotherapy. Strategy C was combination chemotherapy from the outset. Within strategies B and C, patients were randomly assigned to receive, as the combination regimen, fluorouracil plus irinotecan (groups B-ir and C-ir) or fluorouracil plus oxaliplatin (groups B-ox and C-ox). The primary endpoint was overall survival, analysed by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN 79877428. RESULTS Median survival of patients allocated to control strategy A was 13.9 months. Median survival of each of the other groups was longer (B-ir 15.0, B-ox 15.2, C-ir 16.7, and C-ox 15.4 months). However, log-rank comparison of each group against control showed that only C-ir--the first-line combination strategy including irinotecan--satisfied the statistical test for superiority (p=0.01). Overall comparison of strategy B with strategy C was within the predetermined non-inferiority boundary of HR=1.18 or less (HR=1.06, 90% CI 0.97-1.17). INTERPRETATION Our data challenge the assumption that, in this non-curative setting, maximum tolerable treatment must necessarily be used first-line. The staged approach of initial single-agent treatment upgraded to combination when required is not worse than first-line combination, and is an alternative option for discussion with patients.

Prospective randomized trial comparing mitomycin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) With epirubicin, cisplatin, and PVI 5-FU in advanced esophagogastric cancer.

PURPOSE We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) (ECF) with the combination of mitomycin, cisplatin, and PVI 5-FU (MCF) in previously untreated patients with advanced esophagogastric cancer. PATIENTS AND METHODS Five hundred eighty patients with adenocarcinoma, squamous carcinoma, or undifferentiated carcinoma were randomized to receive either ECF (epirubicin 50 mg/m(2) every 3 weeks, cisplatin 60 mg/m(2) every 3 weeks and PVI 5-FU 200 mg/m(2)/d) or MCF (mitomycin 7 mg/m(2) every 6 weeks, cisplatin 60 mg/m(2) every 3 weeks, and PVI 5-FU 300 mg/m(2)/d) and analyzed for survival, response, toxicity, and quality of life (QOL). RESULTS The overall response rate was 42.4% (95% confidence interval [CI], 37% to 48%) with ECF and 44.1% (95% CI, 38% to 50%) with MCF (P =.692). Toxicity was tolerable, and there were only two toxic deaths. ECF resulted in more grade 3/4 neutropenia and grade 2 alopecia, but MCF caused more thrombocytopenia and plantar-palmar erythema. Median survival was 9.4 months with ECF and 8.7 months with MCF (P =.315); at 1 year, 40.2% (95% CI, 34% to 46%) of ECF and 32.7% (95% CI, 27% to 38%) of MCF patients were alive. Median failure-free survival was 7 months with both regimens. Global QOL scores were better with ECF at 3 and 6 months. CONCLUSION This study confirms response, survival, and QOL benefits of ECF observed in a previous randomized study. The equivalent efficacy of MCF was demonstrated, but QOL was superior with ECF. ECF remains one of the reference treatments for advanced esophagogastric cancer.

KRAS and BRAF Mutations in Advanced Colorectal Cancer Are Associated With Poor Prognosis but Do Not Preclude Benefit From Oxaliplatin or Irinotecan: Results From the MRC FOCUS Trial

PURPOSE Activating mutation of the KRAS oncogene is an established predictive biomarker for resistance to anti-epidermal growth factor receptor (anti-EGFR) therapies in advanced colorectal cancer (aCRC). We wanted to determine whether KRAS and/or BRAF mutation is also a predictive biomarker for other aCRC therapies. PATIENTS AND METHODS The Medical Research Council Fluorouracil, Oxaliplatin and Irinotecan: Use and Sequencing (MRC FOCUS) trial compared treatment sequences including first-line fluorouracil (FU), FU/irinotecan or FU/oxaliplatin in aCRC. Tumor blocks were obtained from 711 consenting patients. DNA was extracted and KRAS codons 12, 13, and 61 and BRAF codon 600 were assessed by pyrosequencing. Mutation (mut) status was assessed first as a prognostic factor and then as a predictive biomarker for the benefit of adding irinotecan or oxaliplatin to FU. The association of BRAF-mut with loss of MLH1 was assessed by immunohistochemistry. RESULTS Three hundred eight (43.3%) of 711 patients had KRAS-mut and 56 (7.9%) of 711 had BRAF-mut. Mutation of KRAS, BRAF, or both was present in 360 (50.6%) of 711 patients. Mutation in either KRAS or BRAF was a poor prognostic factor for overall survival (OS; hazard ratio [HR], 1.40; 95% CI, 1.20 to 1.65; P < .0001) but had minimal impact on progression-free survival (PFS; HR, 1.16; 95% CI, 1.00 to 1.36; P = .05). Mutation status did not affect the impact of irinotecan or oxaliplatin on PFS or OS. BRAF-mut was weakly associated with loss of MLH1 staining (P = .012). CONCLUSION KRAS/BRAF mutation is associated with poor prognosis but is not a predictive biomarker for irinotecan or oxaliplatin. There is no evidence that patients with KRAS/BRAF mutated tumors are less likely to benefit from these standard chemotherapy agents.

Value of Mismatch Repair, KRAS, and BRAF Mutations in Predicting Recurrence and Benefits From Chemotherapy in Colorectal Cancer

PURPOSE It is uncertain whether modest benefits from adjuvant chemotherapy in stage II colorectal cancer justify the toxicity, cost, and inconvenience. We investigated the usefulness of defective mismatch repair (dMMR), BRAF, and KRAS mutations in predicting tumor recurrence and sensitivity to chemotherapy. PATIENTS AND METHODS Immunohistochemistry for dMMR and pyrosequencing for KRAS/BRAF were performed for 1,913 patients randomly assigned between fluorouracil and folinic acid chemotherapy and no chemotherapy in the Quick and Simple and Reliable (QUASAR) trial. RESULTS Twenty-six percent of 695 right-sided colon, 3% of 685 left-sided colon, and 1% of 407 rectal tumors were dMMR. Similarly, 17% of right colon, 2% of left colon, and 2% of rectal tumors were BRAF mutant. KRAS mutant tumors were more evenly distributed: 40% right colon, 28% left colon, and 36% rectal tumors. Recurrence rate for dMMR tumors was half that for MMR-proficient tumors (11% [25 of 218] v 26% [438 of 1,695] recurred; risk ratio [RR], 0.53; 95% CI, 0.40 to 0.70; P < .001). Risk of recurrence was also significantly higher for KRAS mutant than KRAS wild-type tumors (28% [150 of 542] v 21% [219 of 1,041]; RR, 1.40; 95% CI, 1.12 to 1.74; P = .002) but did not differ significantly between BRAF mutant and wild-type tumors (P = .36). No marker predicted benefit from chemotherapy with efficacy not differing significantly by MMR, KRAS, or BRAF status. The prognostic value of MMR and KRAS was similar in the presence and absence of chemotherapy. CONCLUSION MMR assays identify patients with a low risk of recurrence. KRAS mutational analysis provides useful additional risk stratification to guide use of chemotherapy.

Predictive Biomarkers of Chemotherapy Efficacy in Colorectal Cancer: Results From the UK MRC FOCUS Trial

PURPOSE Candidate predictive biomarkers for irinotecan and oxaliplatin were assessed in 1,628 patients in Fluorouracil, Oxaliplatin, CPT-11: Use and Sequencing (FOCUS), a large randomized trial of fluorouracil alone compared with fluorouracil and irinotecan and compared with fluorouracil and oxaliplatin in advanced colorectal cancer. METHODS The candidate biomarkers were: tumor immunohistochemistry for MLH1/MSH2, p53, topoisomerase-1 (Topo1), excision repair cross-complementing gene 1 (ERCC1), O-6-methylguanine-DNA-methyltranserase (MGMT), and cyclooxygenase 2 (COX2); germline DNA polymorphisms in GSTP1, ABCB1, XRCC1, ERCC2, and UGT1A1. These were screened in more than 750 patients for interaction with benefit from irinotecan or oxaliplatin; two markers (Topo1 and MLH1/MSH2) met criteria to be taken forward for analysis in the full population. Primary end points were progression-free survival (PFS) and overall survival. RESULTS One thousand three hundred thirteen patients (81%) were assessable for Topo1 immunohistochemistry (low, < 10%; moderate, 10% to 50%; or high, > 50% tumor nuclei). In patients with low Topo1, PFS was not improved by the addition of either irinotecan (hazard ratio [HR], 0.98; 95% CI, 0.78 to 1.22) or oxaliplatin (HR, 0.85; 95% CI, 0.68 to 1.07); conversely, patients with moderate/high Topo1 benefited from the addition of either drug (HR, 0.48 to 0.70 in all categories; interaction P = .005; overall, P = .001 for irinotecan; P = .05 for oxaliplatin). High Topo1 was associated with a major overall survival benefit with first-line combination chemotherapy (HR, 0.60; median benefit, 5.3 months); patients with moderate or low Topo1 did not benefit (HR, 0.92 and 1.09, respectively; interaction P = .005). MLH1/MSH2 did not show significant interaction with treatment, although the low rate of loss (4.4%) limits the power of the study for this biomarker. CONCLUSION Topo1 immunohistochemistry identified subpopulations that did or did not benefit from irinotecan, and possibly also from oxaliplatin. If verified independently, this information will contribute to the individualization of treatment for colorectal cancer.

Chemotherapy options in elderly and frail patients with metastatic colorectal cancer (MRC FOCUS2): an open-label, randomised factorial trial

Summary Background Elderly and frail patients with cancer, although often treated with chemotherapy, are under-represented in clinical trials. We designed FOCUS2 to investigate reduced-dose chemotherapy options and to seek objective predictors of outcome in frail patients with advanced colorectal cancer. Methods We undertook an open, 2 × 2 factorial trial in 61 UK centres for patients with previously untreated advanced colorectal cancer who were considered unfit for full-dose chemotherapy. After comprehensive health assessment (CHA), patients were randomly assigned by minimisation to: 48-h intravenous fluorouracil with levofolinate (group A); oxaliplatin and fluorouracil (group B); capecitabine (group C); or oxaliplatin and capecitabine (group D). Treatment allocation was not masked. Starting doses were 80% of standard doses, with discretionary escalation to full dose after 6 weeks. The two primary outcome measures were: addition of oxaliplatin ([A vs B] + [C vs D]), assessed with progression-free survival (PFS); and substitution of fluorouracil with capecitabine ([A vs C] + [B vs D]), assessed by change from baseline to 12 weeks in global quality of life (QoL). Analysis was by intention to treat. Baseline clinical and CHA data were modelled against outcomes with a novel composite measure, overall treatment utility (OTU). This study is registered, number ISRCTN21221452. Findings 459 patients were randomly assigned (115 to each of groups A–C, 114 to group D). Factorial comparison of addition of oxaliplatin versus no addition suggested some improvement in PFS, but the finding was not significant (median 5·8 months [IQR 3·3–7·5] vs 4·5 months [2·8–6·4]; hazard ratio 0·84, 95% CI 0·69–1·01, p=0·07). Replacement of fluorouracil with capecitabine did not improve global QoL: 69 of 124 (56%) patients receiving fluorouracil reported improvement in global QoL compared with 69 of 123 (56%) receiving capecitabine. The risk of having any grade 3 or worse toxic effect was not significantly increased with oxaliplatin (83/219 [38%] vs 70/221 [32%]; p=0·17), but was higher with capecitabine than with fluorouracil (88/222 [40%] vs 65/218 [30%]; p=0·03). In multivariable analysis, fewer baseline symptoms (odds ratio 1·32, 95% CI 1·14–1·52), less widespread disease (1·51, 1·05–2·19), and use of oxaliplatin (0·57, 0·39–0·82) were predictive of better OTU. Interpretation FOCUS2 shows that with an appropriate design, including reduced starting doses of chemotherapy, frail and elderly patients can participate in a randomised controlled trial. On balance, a combination including oxaliplatin was preferable to single-agent fluoropyrimidines, although the primary endpoint of PFS was not met. Capecitabine did not improve QoL compared with fluorouracil. Comprehensive baseline assessment holds promise as an objective predictor of treatment benefit. Funding Cancer Research UK and the Medical Research Council.

Docetaxel, Cisplatin, and Fluorouracil; Docetaxel and Cisplatin; and Epirubicin, Cisplatin, and Fluorouracil As Systemic Treatment for Advanced Gastric Carcinoma: A Randomized Phase II Trial of the Swiss Group for Clinical Cancer Research

PURPOSE This randomized phase II trial evaluated two docetaxel-based regimens to see which would be most promising according to overall response rate (ORR) for comparison in a phase III trial with epirubicin-cisplatin-fluorouracil (ECF) as first-line advanced gastric cancer therapy. PATIENTS AND METHODS Chemotherapy-naïve patients with measurable unresectable and/or metastatic gastric carcinoma, a performance status <or= 1, and adequate hematologic, hepatic, and renal function randomly received <or= eight 3-weekly cycles of ECF (epirubicin 50 mg/m(2) on day 1, cisplatin 60 mg/m(2) on day 1, and fluorouracil [FU] 200 mg/m(2)/d on days 1 to 21), TC (docetaxel initially 85 mg/m(2) on day 1 [later reduced to 75 mg/m(2) as a result of toxicity] and cisplatin 75 mg/m(2) on day 1), or TCF (TC plus FU 300 mg/m(2)/d on days 1 to 14). Study objectives included response (primary), survival, toxicity, and quality of life (QOL). RESULTS ORR was 25.0% (95% CI, 13% to 41%) for ECF, 18.5% (95% CI, 9% to 34%) for TC, and 36.6% (95% CI, 23% to 53%) for TCF (n = 119). Median overall survival times were 8.3, 11.0, and 10.4 months for ECF, TC, and TCF, respectively. Toxicity was acceptable, with one toxic death (TC arm). Grade 3 or 4 neutropenia occurred in more treatment cycles with docetaxel (TC, 49%; TCF, 57%; ECF, 34%). Global health status/QOL substantially improved with ECF and remained similar to baseline with both docetaxel regimens. CONCLUSION Time to response and ORR favor TCF over TC for further evaluation, particularly in the neoadjuvant setting. A trend towards increased myelosuppression and infectious complications with TCF versus TC or ECF was observed.

Panitumumab and irinotecan versus irinotecan alone for patients with KRAS wild-type, fluorouracil-resistant advanced colorectal cancer (PICCOLO): a prospectively stratified randomised trial

Summary Background Therapeutic antibodies targeting EGFR have activity in advanced colorectal cancer, but results from clinical trials are inconsistent and the population in which most benefit is derived is uncertain. Our aim was to assess the addition of panitumumab to irinotecan in pretreated advanced colorectal cancer. Methods In this open-label, randomised trial, we enrolled patients who had advanced colorectal cancer progressing after fluoropyrimidine treatment with or without oxaliplatin from 60 centres in the UK. From December, 2006 until June, 2008, molecularly unselected patients were recruited to a three-arm design including irinotecan (control), irinotecan plus ciclosporin, and irinotecan plus panitumumab (IrPan) groups. From June 10, 2008, in response to new data, the trial was amended to a prospectively stratified design, restricting panitumumab randomisation to patients with KRAS wild-type tumours; the results of the comparison between the irinotcan and IrPan groups are reported here. We used a computer-generated randomisation sequence (stratified by previous EGFR targeted therapy and then minimised by centre, WHO performance status, previous oxaliplatin, previous bevacizumab, previous dose modifications, and best previous response) to randomly allocate patients to either irinotecan or IrPan. Patients in both groups received 350 mg/m2 intravenous irinotecan every 3 weeks (300 mg/m2 if aged ≥70 years or a performance status of 2); patients in the IrPan group also received intravenous panitumumab 9 mg/kg every 3 weeks. The primary endpoint was overall survival in KRAS wild-type patients who had not received previous EGFR targeted therapy, analysed by intention to treat. Tumour DNA was pyrosequenced for KRASc.146, BRAF, NRAS, and PIK3CA mutations, and predefined molecular subgroups were analysed for interaction with the effect of panitumumab. This study is registered, number ISRCTN93248876. Results Between Dec 4, 2006, and Aug 31, 2010, 1198 patients were enrolled, of whom 460 were included in the primary population of patients with KRASc.12–13,61 wild-type tumours and no previous EGFR targeted therapy. 230 patients were randomly allocated to irinotecan and 230 to IrPan. There was no difference in overall survival between groups (HR 1·01, 95% CI 0·83–1·23; p=0·91), but individuals in the IrPan group had longer progression-free survival (0·78, 0·64–0·95; p=0·015) and a greater number of responses (79 [34%] patients vs 27 [12%]; p<0·0001) than did individuals in the irinotecan group. Grade 3 or worse diarrhoea (64 [29%] of 219 patients vs 39 [18%] of 218 patients), skin toxicity (41 [19%] vs none), lethargy (45 [21]% vs 24 [11%]), infection (42 [19%] vs 22 [10%]) and haematological toxicity (48 [22%] vs 27 [12%]) were reported more commonly in the IrPan group than in the irinotecan group. We recorded five treatment-related deaths, two in the IrPan group and three in the irinotecan group. Interpretation Adding panitumumab to irinotecan did not improve the overall survival of patients with wild-type KRAS tumours. Further refinement of molecular selection is needed for substantial benefits to be derived from EGFR targeting agents. Funding Cancer Research UK, Amgen Inc.

Irinotecan/fluorouracil combination in first-line therapy of older and younger patients with metastatic colorectal cancer: combined analysis of 2,691 patients in randomized controlled trials.

PURPOSE Uncertainty exists about whether elderly patients benefit to the same extent as younger patients from combination therapy with irinotecan in the first-line treatment of metastatic colorectal cancer (CRC). PATIENTS AND METHODS Combined analysis was carried out with source data from the fluorouracil (FU)/folinic acid (FA) and the irinotecan/FU/FA arms of four first-line, phase III trials of CRC to investigate the efficacy and safety of combination and monotherapy in elderly (age > or = 70 years; n = 599) compared with younger (age < 70 years; n = 2,092) patients. RESULTS Response rates were improved with irinotecan-based combination therapy compared with FU/FA in patients both younger than 70 years and > or = 70 years (46.6% v 29.0% P < .0001; and 50.5% v 30.3%, P < .0001, respectively). With irinotecan/FU/FA, progression-free survival was better for both younger (hazard ratio [HR], 0.77; 95% CI, 0.70 to 0.85; P < .0001) and elderly patients (HR, 0.75; 95% CI, 0.61 to 0.90; P = .0026). In younger patients, overall survival was improved with combination therapy (HR, 0.83; 95% CI, 0.75 to 0.92; P = .0003). The same trend was observed in elderly patients (HR, 0.87; 95% CI, 0.72 to 1.05; P = .15). There was no significant interaction between treatment arm and age in the regression analysis. The expected differences in toxicity between combination and monotherapy in elderly and younger patients were observed. A significant interaction between treatment and age (cutoff, 70 years) for vomiting and hepatotoxicity was not confirmed by analysis that used age as a continuous variable. CONCLUSION Patients older than 70 years of age who were selected for inclusion in phase III trials derived similar benefits as younger patients from irinotecan-containing chemotherapy, and the risk of toxicity was similar.