Second‐line cetuximab/irinotecan versus oxaliplatin/fluoropyrimidines for metastatic colorectal cancer with wild‐type KRAS

The goal of the present study was to compare the efficacy of the combination of cetuximab and irinotecan to the combination of oxaliplatin and fluoropyrimidines as second‐line chemotherapy in patients with irinotecan‐refractory and oxaliplatin‐naïve metastatic colorectal cancer (mCRC) harboring wild‐type KRAS. The study included 120 patients with mCRC who had progressed after irinotecan‐containing first‐line chemotherapy and were never treated with oxaliplatin; 40 patients with wild‐type KRAS were accrued prospectively in the experimental arm (arm A), and 80 patients accrued retrospectively were divided into control arms B (n = 46) and C (n = 34) according to KRAS genotype. Second‐line treatments consisted of cetuximab plus irinotecan for arm A, and oxaliplatin plus either 5‐fluorouracil (FOLFOX) or capecitabine (CapeOX) for the control arms. The median progression‐free survival (PFS) was 8.3, 5.8 and 3.9 months, for arms A, B and C, respectively, with statistical significance favoring arm A (P = 0.007). Differences in overall survival did not reach statistical significance (18.3 vs 12.6 vs 12.9, P = 0.138), although there was a trend toward longer overall survival in arm A. In terms of benefit from oxaliplatin‐containing regimens either as second‐line or third‐line therapy, the median PFS was 5.0 months in arms B and C as second‐line therapy, and 4.0 months in arm A as third‐line therapy, with no statistical significance (P = 0.385). Second‐line cetuximab plus irinotecan is a valid treatment strategy for mCRC patients with irinotecan‐refractory and oxaliplatin‐naïve tumors harboring wild‐type KRAS. Oxaliplatin‐containing chemotherapy resulted in equivalent PFS both as a second‐line and a third‐line therapy, enabling delay of the administration of FOLFOX and CapeOX until subsequent treatment cycles.     

Retrospective analysis of cetuximab monotherapy for patients with irinotecan-intolerant metastatic colorectal cancer

Background

The efficacy and safety of cetuximab for irinotecan-intolerant patients has not yet been evaluated in detail.

Methods

We retrospectively analyzed the efficacy and safety of cetuximab monotherapy for patients with metastatic colorectal cancer (MCRC) that was intolerant to irinotecan.

Results

Among 105 patients who received cetuximab-containing chemotherapy until March 2010, 22 patients were treated with cetuximab monotherapy due to irinotecan intolerance. Cetuximab was given at the approved dosage to all patients. The performance status was 2 or 3 in 17 patients (77%). All but 1 patient had wild-type KRAS tumors. The causes of irinotecan intolerance were icterus (n?=?9; 41%; median serum total bilirubin, 6.3?mg/dl), symptomatic peritoneal metastasis or obstruction (n?=?8; 36%), and thrombocytopenia (n?=?1; 5%). Four patients (18%) refused irinotecan due to previous irinotecan-associated toxicity. Two patients achieved a partial response with an apparent drop of serum bilirubin, for a response rate of 9.1%. The median progression-free survival and overall survival were 1.6 and 3.5?months, respectively. No grade 3 or 4 adverse events or treatment-related deaths were experienced.

Conclusion

Cetuximab monotherapy for irinotecan-intolerant MCRC is feasible. However, the overall efficacy was modest in the present cohort, despite the fact that most of the patients had wild-type KRAS tumors; further effective therapies should be evaluated to improve the prognosis of this patient population.     

Efficacy of FOLFIRI-3 (irinotecan D1,D3 combined with LV5-FU) or other irinotecan-based regimens in oxaliplatin-pretreated metastatic colorectal cancer in the GERCOR OPTIMOX1 study

Background: Second-line irinotecan-based chemotherapy is commonly used in metastatic colorectal cancers after first-line oxaliplatin-based chemotherapy. No standard schedule of irinotecan has been established in this situation.Patients and methods: Metastatic colorectal cancer patients included in the OPTIMOX1 phase III study received first-line oxaliplatin-based chemotherapy (FOLFOX). No second line was defined in the protocol, but data concerning second line were prospectively registered. Inclusion criterion was patients receiving an irinotecan-based second-line chemotherapy. Second-line progression-free survival (PFS) and tumor response were evaluated according to type of irinotecan-based regimen administered.Results: A total of 342 patients received irinotecan-based chemotherapy as second-line chemotherapy: FOLFIRI-3 [n = 109, irinotecan 100 mg/m² days 1 and 3 combined with leucovorin (LV) 400 mg/m² day 1 and 46-h continuous 5-fluorouracil (5-FU) 2000 mg/m²], FOLFIRI-1 (n = 112, irinotecan 180 mg/m² day 1 combined with LV 400 mg/m² day 1, 5-FU bolus 400 mg/m² and 46-h continuous 5-FU 2400 mg/m²) and other various irinotecan-based regimens (n = 121). Median second-line PFS was 3.0 months (FOLFIRI-3: 3.7 months; FOLFIRI-1: 3.0 months; other regimens: 2.3 months). In multivariate analysis, FOLFIRI-3 regimen (relative risk 0.43, 95% confidence interval 0.28–0.68, P = 0.0003) and lactate deshydrogenase level at inclusion (P = 0.0006) in OPTIMOX1 were associated with a longer second-line PFS.Conclusion: In unselected patients pretreated with oxaliplatin, PFS in second line appeared to be improved by FOLFIRI-3 regimen.     

Phase III trial of irinotecan plus infusional 5-fluorouracil/folinic acid versus irinotecan plus oxaliplatin as first-line treatment of advanced colorectal cancer

Purpose

To determine whether irinotecan plus oxaliplatin (mIROX) is superior to irinotecan plus infusional 5-fluorouracil, leucovorin (FUFIRI) as first-line therapy of patients with metastatic colorectal cancer (mCRC).

Patients and methods

A phase III, randomised, open-label multicentre study compared standard treatment with FUFIRI (irinotecan 80 mg/m², 5-fluorouracil 2000 mg/m², folinic acid 500 mg/m² weekly times 6) to mIROX using an identical schedule of irinotecan plus oxaliplatin 85 mg/m² applied on days 1, 15 and 29 of a 7-week cycle. The primary end-point was progression-free survival (PFS).

Results

A total of 479 eligible patients were randomly assigned. Progression-free survival was 7.2 months in the mIROX arm and 8.2 months in the FUFIRI arm [hazard ratio = 1.14; 95% confidence interval (CI) 0.94-1.37; P = 0.178]. Comparable results were also obtained for overall survival time with 19 months in the mIROX-arm and 22 months in the FUFIRI-arm (hazard ratio = 1.08, P = 0.276). Both regimens induced an identical objective response rate (ORR) of 41%, but disease control rate (ORR plus stable disease) was significantly greater in the FUFIRI group (81% versus 68%, P = 0.001). Most frequent grades 1-4 side-effects of mIROX and FUFIRI treatment were nausea (80% versus 73%) and delayed diarrhoea (79% versus 68%). Grades 3-4 toxicities were generally below 10%, except for diarrhoea which was more frequent in the mIROX-arm compared to the FUFIRI-arm (19% versus 30%, P = 0.006)

Conclusion

mIROX failed to show superior activity compared to high-dose 5-FU/folinic acid plus irinotecan. Due to better tolerability the combination of high-dose 5-FU/folinic acid and irinotecan remains a standard of care in first-line treatment of metastatic colorectal cancer.     

<Emphasis Type="Italic">MDR1</Emphasis> polymorphism role in patients treated with cetuximab and irinotecan in irinotecan refractory colorectal cancer

The aim of the study was to evaluate the influence of the MDR1 C3435T polymorphism on the therapeutic response in 23 patients treated with cetuximab plus irinotecan for irinotecan refractory liver metastatic colorectal cancer considering their KRAS status. Indeed, irinotecan and its active metabolite (SN-38) are both substrates of P-glycoprotein (P-gp) encoded by MDR1. Patients received cetuximab and irinotecan up to progression. The overall survival was 55% at 10 months. Overall, four patients had an undetermined KRAS status and two patients with mutated KRAS were in progression disease. The response to treatment was observed after 3 months among the 17 wild-type KRAS patients. Two patients presented a progressive disease (1 TT and 1 CT), eight patients had a stable disease (5 CC and 3CT) and five patients had a partial response (3 CC and 2 CT). Importantly, 2 patients (2 TT) were in complete response and still alive 5 years after starting the treatment, which suggests that the combination of wild-type KRAS and MDR1 3435 TT may be a factor of good prognosis. These results suggest that EGFR inhibition by cetuximab may overcome this irinotecan resistance by abrogating drug efflux depending on MDR1 3435 polymorphism. Among patients resistant to irinotecan, it is still possible to use the association of cetuximab plus irinotecan to obtain a complete resection of hepatic metastases that is necessary to improve their survival.     

GSTP1 Ile105Val polymorphism correlates with progression-free survival in MCRC patients treated with or without irinotecan: a study of the Dutch Colorectal Cancer Group

A Valine residue at position 105 of the GSTP1 protein results in decreased enzyme activity. As nuclear GSTP1 activity decreases irinotecan cytotoxicity, Val-allele carriers may benefit more from irinotecan chemotherapy. Our aim was to investigate the association of GSTP1 genotype with treatment outcome of irinotecan. Progression-free survival (PFS) and toxicity were determined in 267 metastatic colorectal cancer (MCRC) patients who were treated with first-line capecitabine (CAP) plus irinotecan (CAPIRI), or CAP single agent in a prospective randomised phase III trial (CAIRO). GSTP1 genotype was determined by Pyrosequencing. Patients receiving CAP showed a PFS of 6.6 (Ile/Ile), 6.0 (Ile/Val) and 6.5 months (Val/Val); compared to 7.0 (Ile/Ile), 8.8 (Ile/Val) and 9.2 months (Val/Val) with CAPIRI. Median PFS was 2.7 months longer in Val-allele carriers treated with CAPIRI compared to CAP (P=0.005). Patients with the Ile/Ile genotype showed similar PFS with CAPIRI and CAP (7.0 compared to 6.6 months, P=0.972). Toxicity did not differ significantly among genotypes. GSTP1 codon 105 polymorphism may be predictive for the response to irinotecan-based chemotherapy in patients with MCRC, with the Val-allele being associated with a better outcome. Ile/Ile genotype patients do not appear to benefit from the addition of irinotecan to CAP.     

KRAS codon 61, 146 and BRAF mutations predict resistance to cetuximab plus irinotecan in KRAS codon 12 and 13 wild-type metastatic colorectal cancer

Background:

KRAS codons 12 and 13 mutations predict resistance to anti-EGFR monoclonal antibodies (moAbs) in metastatic colorectal cancer. Also, BRAF V600E mutation has been associated with resistance. Additional KRAS mutations are described in CRC.

Methods:

We investigated the role of KRAS codons 61 and 146 and BRAF V600E mutations in predicting resistance to cetuximab plus irinotecan in a cohort of KRAS codons 12 and 13 wild-type patients.

Results:

Among 87 KRAS codons 12 and 13 wild-type patients, KRAS codons 61 and 146 were mutated in 7 and 1 case, respectively. None of mutated patients responded vs 22 of 68 wild type (P=0.096). Eleven patients were not evaluable. KRAS mutations were associated with shorter progression-free survival (PFS, HR: 0.46, P=0.028). None of 13 BRAF-mutated patients responded vs 24 of 74 BRAF wild type (P=0.016). BRAF mutation was associated with a trend towards shorter PFS (HR: 0.59, P=0.073). In the subgroup of BRAF wild-type patients, KRAS codons 61/146 mutations determined a lower response rate (0 vs 37%, P=0.047) and worse PFS (HR: 0.45, P=0.023). Patients bearing KRAS or BRAF mutations had poorer response rate (0 vs 37%, P=0.0005) and PFS (HR: 0.51, P=0.006) compared with KRAS and BRAF wild-type patients.

Conclusion:

Assessing KRAS codons 61/146 and BRAF V600E mutations might help optimising the selection of the candidate patients to receive anti-EGFR moAbs.     

A randomised,open-label phase II trial of afatinib versus cetuximab in patients with metastatic colorectal cancer

PurposeThis randomised phase II trial aimed to compare efficacy of the irreversible ErbB family blocker, afatinib, with cetuximab in patients with KRAS wild-type metastatic colorectal adenocarcinoma (mCRC) with progression following oxaliplatin- and irinotecan-based regimens. Efficacy in patients with KRAS mutations was also evaluated.Patients and methodsPatients with KRAS wild-type tumours were randomised 2:1 to afatinib (40 mg/day, increasing to 50 mg/day if minimal toxicity) or cetuximab weekly (400 mg/m² loading dose, then 250 mg/m²/week) according to number of previous chemotherapy lines. All patients with KRAS-mutated tumours received afatinib. Primary end-points were objective response (OR) for the wild-type group and disease control for the KRAS-mutated group. Secondary end-points were progression-free survival (PFS) and overall survival (OS).ResultsPatients with KRAS wild-type tumours (n = 50) received afatinib (n = 36) or cetuximab (n = 14). Unconfirmed and confirmed ORs were 3% and 0% for afatinib versus 20% and 13% for cetuximab (odds ratio: 0.122 [P = 0.0735] and <0.001, respectively). Median PFS was 46.0 and 144.5 days for afatinib and cetuximab, respectively. Median OS was 355 days with afatinib but not reached for cetuximab. In the KRAS-mutated group (n = 41), five (12%) patients achieved confirmed disease control (stable disease; P = 0.6394 [comparison versus 10%]); no ORs were reported. Median PFS and OS were 41.0 and 173 days, respectively. Most frequent treatment-related adverse events were diarrhoea and rash across groups.ConclusionsThe efficacy of afatinib was inferior to cetuximab in patients with KRAS wild-type mCRC. In patients with KRAS-mutated tumours, disease control was modest with afatinib. Afatinib had a manageable safety profile.     

The importance of KRAS mutations and EGF61A>G polymorphism to the effect of cetuximab and irinotecan in metastatic colorectal cancer

BackgroundThe effect of anti-epidermal growth factor receptor (EGFR) antibodies (mAb) in metastatic colorectal cancer seems limited to KRAS wild-type (wt) tumours, but still a major fraction of KRASwt patients are nonresponders and supplementary selection criteria are needed. We investigated methodological aspects of KRAS testing and the predictive and prognostic value of KRAS status combined with three EGFR-related gene polymorphisms [single-nucleotide polymorphisms (SNPs)] in patients treated with cetuximab and irinotecan.Patients and methodsThe study included 71 patients referred to third-line cetuximab–irinotecan. Blood samples were analysed for SNPs. KRAS analysis was carried out by sequencing analysis and quantitative PCR (DxS kit) in primary tumour and distant metastases.ResultsThere was a clear correlation between KRAS status in primary tumours and metastasis. The DxS kit presented the highest sensitivity. Response was confined to KRASwt patients (40% response rate versus 0%, P < 0.1^-3), which translated into a significant difference in PFS. The EGF61A>G polymorphism showed relation to clinical outcome. A combined biomarker analysis showed a 19% progression rate in KRASwt-EGF61 homozygote patients and 60% in the EGF61A/G patients (P = 0.006) and a significant increase in overall survival (17.1 versus 5.9 months, log-rank, P = 0.002).ConclusionThe combined biomarker analysis maybe an attractive approach to selection of patients for third-line treatment including anti-EGFR mAbs.     

A randomized,placebo‐controlled,phase 1/2 study of tivantinib (ARQ 197) in combination with irinotecan and cetuximab in patients with metastatic colorectal cancer with wild‐type KRAS who have received first‐line systemic therapy

Cetuximab in combination with an irinotecan‐containing regimen is a standard treatment in patients with KRAS wild‐type (KRAS WT), metastatic colorectal cancer (mCRC). We investigated the addition of the oral MET inhibitor tivantinib to cetuximab + irinotecan (CETIRI) based on preclinical evidence that activation of the MET pathway may confer resistance to anti‐EGFR therapy. Previously treated patients with KRAS WT advanced or mCRC were enrolled. The phase 1, open‐label 3 + 3, dose‐escalation study evaluated the safety and maximally tolerated dose of tivantinib plus CETIRI. The phase 2, randomized, double‐blinded, placebo‐controlled study of biweekly CETIRI plus tivantinib or placebo was restricted to patients who had received only one prior line of chemotherapy. The phase 2 primary endpoint was progression‐free survival (PFS). The recommended phase 2 dose was tivantinib (360 mg/m² twice daily) with biweekly cetuximab (500 mg/m²) and irinotecan (180 mg/m²). Among 117 patients evaluable for phase 2 analysis, no statistically significant PFS difference was observed: 8.3 months on tivantinib vs. 7.3 months on placebo (HR, 0.85; 95% confidence interval, 0.55–1.33; P = 0.38). Subgroup analyses trended in favor of tivantinib in patients with MET‐High tumors by immunohistochemistry, PTEN‐Low tumors, or those pretreated with oxaliplatin, but subgroups were too small to draw conclusions. Neutropenia, diarrhea, nausea and rash were the most frequent severe adverse events in tivantinib‐treated patients. The combination of tivantinib and CETIRI was well tolerated but did not significantly improve PFS in previously treated KRAS WT mCRC. Tivantinib may be more active in specific subgroups.     

A systematic review and meta-analysis of KRAS status as the determinant of response to anti-EGFR antibodies and the impact of partner chemotherapy in metastatic colorectal cancer

Background

In the setting of metastatic colorectal cancer (CRC), anti-EGFR antibodies are not currently recommended for individuals with KRAS mutant tumours. This is based on subgroup analyses of individual clinical trials rather than a formal synthesis of evidence for KRAS status as a predictive biomarker, while newer trials report no benefit for anti-EGFR antibodies irrespective of KRAS status. This study systematically reviewed the evidence for KRAS mutation status as a treatment effect modifier of response to anti-EGFR antibodies and the influence of partner chemotherapy.

Methods

Medline (1966-2010), EMBASE and American and European oncology meeting abstracts were searched for randomised controlled trials reporting the influence of KRAS status on effectiveness of anti-EGFR antibodies in metastatic CRC. The treatment efficacy was summarised by KRAS status using hazard ratios (HR) for progression-free survival (PFS) and risk differences (RD) for objective response. For each study, a measure of effect modification was calculated, and aggregated using random effects meta-analysis to assess the interaction between KRAS and treatment effect.

Findings

Eleven studies (8924 patients) were selected from 198 reports. Two studies assessed anti-EGFR antibodies as monotherapy and nine their use with chemotherapy. KRAS status was reported in 7555 cases. In subgroup analysis, the progression HR for KRAS wild patients assigned to anti-EGFR antibodies was 0.80 (4436 patients 95%CI: 0.64, 0.99) and for mutant cases 1.11 (3119 patients, 95%CI: 0.97, 1.27). A significant treatment effect interaction between KRAS status and addition of anti-EGFR antibodies to standard treatment was found for PFS (ratio of HRs 0.71, 95%CI: 0.57, 0.90 p = 0.005) and response rate difference (difference in RDs 15%, 95%CI: 8, 22%, p < 0.001). There was no evidence that the extent of effect modification differed between chemotherapeutic partners for both PFS (p = 0.3) and response rate (p = 0.6).

Interpretation

KRAS mutation status is a treatment effect modifier for anti-EGFR antibodies in metastatic CRC. Further evidence is needed to determine whether this is true for all chemotherapy partners and all clinical circumstances.     

Predictive factors for the efficacy of cetuximab plus chemotherapy as salvage therapy in metastatic gastric cancer patients

Purpose

We performed a retrospective study to evaluate the efficacy of cetuximab plus chemotherapy in metastatic gastric cancer (MGC) patients previously treated with chemotherapy and to investigate potential predictors of treatment efficacy in those patients.

Methods

Thirty-two patients with MGC were included in this study. Cetuximab was delivered, often combined with irinotecan-based chemotherapy. Thirty patients were analyzed for K-ras mutations via direct sequencing of the tumor DNA.

Results

Patients were heavily pretreated with a median number of three previous lines of palliative chemotherapy (56% of the patients were refractory to all of the following drugs: fluoropyrimidines, cisplatin, irinotecan, oxaliplatin, and docetaxel) and 53% of the patients displayed poor performance status. Of 28 response-assessable patients, the overall response rate to cetuximab plus chemotherapy was 3.6% [95% confidence interval (CI) 0–10.5%] and the disease control rate was 28.6%. The median progression-free survival (PFS) was 1.7 months (95% CI 1.3–2.1 months), and the median overall survival (OS) was 3.2 months (95% CI 1.4–5.0 months). Multivariate analyses revealed that skin rash and performance status were significantly associated with PFS and OS. The presence of a K-ras mutation (13.3%) was not associated with either PFS or OS.

Conclusion

Our study suggests that MGC patients with good performance status and skin rash benefit most from salvage cetuximab combined with chemotherapy, even in heavily pretreated status.     

Serum matrilysin correlates with poor survival independently of <Emphasis Type="Italic">KRAS</Emphasis> and <Emphasis Type="Italic">BRAF</Emphasis> status in refractory advanced colorectal cancer patients treated with irinotecan plus cetuximab

The purpose of the study was to prospectively explore the role of serum MMP-7 as a predictive and prognostic marker of anti-epidermal growth factor receptor (EGFR) therapy and irinotecan efficacy in third-line advanced colorectal cancer therapy. One hundred patients were recruited prospectively from six Spanish hospitals. Patients were treated with biweekly irinotecan 180 mg/m² and cetuximab 400 mg/m² (loading dose) and weekly cetuximab 250 mg/m² until progressive disease or unacceptable toxicity. Baseline MMP-7 was determined using a quantitative solid-phase sandwich ELISA. KRAS and BRAF mutational status were also assessed. The clinical endpoints examined were overall survival (OS), progression-free survival (PFS), and response rate. No association between serum MMP-7 and neither KRAS nor BRAF mutational status was found. The multivariate analysis revealed that MMP-7 predicts PFS both in wild-type (WT) KRAS patients (HR 1.03, 95% CI 1.00–1.06; p = 0.046) and in mutant KRAS patients (HR 1.18, 95% CI 1.01–1.35; p = 0.036). The presence of mutant BRAF was associated with shorter PFS (HR 8.49, 95% CI 2.88–25.0; p < 0.001) and worse OS (HR 3.55, 95% CI 1.39–9.09; p = 0.008) in the subset of WT KRAS patients. Serum MMP-7 is associated with PFS in colorectal patients treated with anti-EGFR therapy as third-line treatment independently of KRAS status.     

FOLFIRI plus cetuximab or bevacizumab for advanced colorectal cancer: final survival and per-protocol analysis of FIRE-3, a randomised clinical trial

Background Cetuximab plus FOLFIRI improved overall survival compared with bevacizumab plus FOLFIRI in KRAS wild-type metastatic colorectal cancer (mCRC) in FIRE-3, but no corresponding benefit was found for progression-free survival. This analysis aimed to determine whether cetuximab improves response and survival versus bevacizumab among response-evaluable patients receiving first-line FOLFIRI for RAS wild-type mCRC and the effect of primary tumour side on outcomes.Methods The intent-to-treat population included 593 patients with KRAS exon 2 wild-type mCRC. Further testing identified 400 patients with extended RAS wild-type disease; of these, 352 (88%) who received ≥3 cycles of therapy and had ≥1 post-baseline scan were evaluable for response and constituted the per-protocol population (169 cetuximab and 183 bevacizumab). Patients received 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) with either weekly cetuximab or biweekly bevacizumab given on day 1 of each 14-day cycle until response, progression or toxicity occurred. The primary endpoint was the objective response rate (ORR) in the per-protocol population. Secondary endpoints included overall survival (OS) and progression-free survival (PFS). The effect of primary tumour location was evaluated.Results Median OS in the RAS wild-type population was 31 vs 26 months in the cetuximab and bevacizumab groups, respectively (HR 0.76, P = 0.012). In the per-protocol population, outcomes favoured cetuximab for ORR (77% vs 65%, P = 0.014) and median OS (33 vs 26 months, HR 0.75, P = 0.011), while PFS was comparable between groups. The advantage of cetuximab over bevacizumab occurred only in patients with left-sided primary tumours.Conclusions FOLFIRI plus cetuximab resulted in a significantly higher ORR and longer OS compared to FOLFIRI plus bevacizumab among patients with left-sided tumours. The superior response associated with cetuximab may particularly benefit patients with symptomatic tumours or borderline-resectable metastases.ClinicalTrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT00433927","term_id":"NCT00433927"}}NCT00433927.Subject terms: Oncology, Biomarkers     

Abituzumab combined with cetuximab plus irinotecan versus cetuximab plus irinotecan alone for patients with KRAS wild-type metastatic colorectal cancer: the randomised phase I/II POSEIDON trial

BackgroundIntegrins are involved in tumour progression and metastasis, and differentially expressed on colorectal cancer (CRC) cells. Abituzumab (EMD 525797), a humanised monoclonal antibody targeting integrin αν heterodimers, has demonstrated preclinical activity. This trial was designed to assess the tolerability of different doses of abituzumab in combination with cetuximab and irinotecan (phase I) and explore the efficacy and tolerability of the combination versus that of cetuximab and irinotecan in patients with metastatic CRC (mCRC) (phase II part).MethodsEligible patients had KRAS (exon 2) wild-type mCRC and had received prior oxaliplatin-containing therapy. The trial comprised an initial safety run-in using abituzumab doses up to 1000 mg combined with a standard of care (SoC: cetuximab plus irinotecan) and a phase II part in which patients were randomised 1 : 1 : 1 to receive abituzumab 500 mg (arm A) or 1000 mg (arm B) every 2 weeks combined with SoC, or SoC alone (arm C). The primary end point was investigator-assessed progression-free survival (PFS). Secondary end points included overall survival (OS), response rate (RR) and tolerability. Associations between tumour integrin expression and outcomes were also assessed.ResultsPhase I showed that abituzumab doses up to 1000 mg were well tolerated in combination with SoC. Seventy-three (arm A), 71 (arm B) and 72 (arm C) patients were randomised to the phase II part. Baseline characteristics were balanced. PFS was similar in the three arms: arm A versus SoC, hazard ratio (HR) 1.13 [95% confidence interval (CI) 0.78–1.64]; arm B versus SoC, HR 1.11 (95% CI 0.77–1.61). RRs were also similar. A trend toward improved OS was observed: arm A versus SoC, HR 0.83 (95% CI 0.54–1.28); arm B versus SoC, HR 0.80 (95% CI 0.52–1.25). Grade ≥3 treatment-emergent adverse events were observed in 72%, 78% and 67% of patients. High tumour integrin αvβ6 expression was associated with longer OS in arms A [HR 0.55 (0.30–1.00)] and B [HR 0.41 (0.21–0.81)] than in arm C.ConclusionThe primary PFS end point was not met, although predefined exploratory biomarker analyses identified subgroups of patients in whom abituzumab may have benefit. The tolerability of abituzumab combined with cetuximab and irinotecan was acceptable. Further study is warranted.ClinicalTrials.gov identifierNCT01008475     

Cetuximab in combination with chemoradiotherapy in Chinese patients with non-resectable,locally advanced esophageal squamous cell carcinoma: A prospective,multicenter phase II trail

Background and purpose

This multicenter phase II trial investigated cetuximab combined with chemoradiotherapy in patients with esophageal squamous cell carcinoma (ESCC).

Material and methods

Eligible patients with non-resectable, locally-advanced ESCC received cetuximab 400 mg/m² loading dose on day 1; and on day 1 of the 2nd–7th weeks: cetuximab 250 mg/m², paclitaxel 45 mg/m², and cisplatin 20 mg/m², concurrent with 59.4 Gy/33 fractions of radiation therapy. Primary endpoint was clinical response rate. Secondary endpoints included overall survival (OS), progression-free survival (PFS), safety, and KRAS status.

Results

Of 55 patients enrolled, 45 completed therapy. Forty-four patients had a clinical response: 29 complete response and 15 partial response. One-year PFS and OS of 45 evaluable patients were 84.23% and 93.33%, respectively, and 2-year PFS and OS were 74.87% and 80.00%, respectively. Non-hematologic adverse events were generally grade 1 or 2; primarily rash (92.7%), mucositis (45.5%), fatigue (41.8%), and nausea (38.2%). Grade 3 hematologic adverse events included neutropenia (32.7%) and anemia (1.8%). No KRAS mutations were identified in 50 evaluated samples.

Conclusions

Cetuximab can be safely administered with chemoradiotherapy to patients with locally-advanced ESCC and may improve clinical response rate.     

Does KRAS mutational status predict chemoresistance in advanced non-small cell lung cancer (NSCLC)?

Background

Clinical implications of KRAS mutational status in advanced non-small cell lung cancer (NSCLC) remain unclear. To clarify this point, we retrospectively explored whether KRAS mutations could impact tumor response, and disease control rate (DCR) to first-line platinum-based chemotherapy (CT) as well as progression-free survival (PFS) or overall survival (OS).

Methods

Between June 2009 and June 2012, 340 patients with advanced (stage IIIB/IV) NSCLC were reviewed in a single institution (Institut Gustave Roussy). Two hundred and one patients had a biomolecular profile and received a platinum-based first-line CT. Patients with an unknown mutational status or with actionable alterations were excluded. We retained two groups: patients with KRAS mutated tumor (MUT) and patients with wild-type KRAS/EGFR (WT). Multivariate analyses with Cox model were used. Survival curves were calculated with Kaplan–Meier method.

Results

One hundred and eight patients were included in the analysis: 39 in the MUT group and 69 in the WT group. Baseline radiological assessment demonstrated more brain (P = 0.01) and liver (P = 0.04) metastases in MUT patients. DCR was 76% for MUT vs. 91% for WT group (P = 0.03), regardless of the type of platinum-based CT (use of pemetrexed or not). Although no statistically significant differences were found, shorter PFS (4.9 vs. 6.0 months; P = 0.79) and OS (10.3 vs. 13.2 months; P = 0.40) were observed for patients with KRAS mutated tumors in univariate analysis.

Conclusions

KRAS mutant tumors had a lower DCR after the first-line platinum-based CT, but this difference did not translate in PFS or OS. The presence of KRAS mutations may confer a more aggressive disease, with greater baseline incidence of hepatic and cerebral metastases.     

Phase II trial of biweekly cetuximab and irinotecan as third‐line therapy for pretreated KRAS exon 2 wild‐type colorectal cancer

Efficacy and safety of biweekly cetuximab plus irinotecan were evaluated to provide guidance for its use in Japan as third‐line treatment for pretreated metastatic colorectal cancer (mCRC) patients harboring wild‐type KRAS exon 2. Objective response rate (ORR) was used as primary endpoint based on an expected proportion of 0.23 with confidence width of 0.298 (95% CI, 0.105‐0.403), which showed 35 to be the minimal participant number. Forty patients, refractory to first‐ and second‐line chemotherapy containing irinotecan, oxaliplatin, and fluoropyrimidine, were enrolled. ORR and disease control rate were 25.0% (95% CI: 11.5‐38.4) and 72.5% (95% CI: 56.8‐86.4), respectively. Median progression‐free survival (PFS), overall survival (OS), and number of courses were 5.70 months (95% CI: 2.7‐7.9), 15.1 months (95% CI: 11.8‐19.0), and 10.5 (range: 3.0‐31.0), respectively. Grade 3 adverse events were skin toxicity (12.5%), diarrhea (10.0%), neutropenia (5.0%), febrile neutropenia (5.0%), nausea (5.0%), anorexia (5.0%), and fatigue (2.5%). C_max mean was 723.2 μg/mL after first dose. High area under the curve (AUC)_last variance was associated with t_1/2 range of 131.2‐1209.6 hours (median, 174.4 hours). Early tumor shrinkage (ETS) and median depth of response were 25.0% and 13.0%, respectively. Mutation frequencies in KRAS exon 3 or 4, NRAS, BRAF, and PIK3CA were 5.5%, 2.7%, 8.3%, and 5.5%, respectively. Multivariate Cox regression analysis assessed whether any gene mutations and ETS are predictors for PFS, and whether performance status, synchronous metastasis, and ETS are predictors for OS. Importantly, the data provide guidance for a biweekly cetuximab plus irinotecan regimen in mCRC patients.     

Clinical usefulness of KRAS, BRAF, and PIK3CA mutations as predictive markers of cetuximab efficacy in irinotecan- and oxaliplatin-refractory Japanese patients with metastatic colorectal cancer

Background

Anti-epidermal growth factor receptor (EGFR) antibodies, cetuximab, and panitumumab are established as a new treatment option for metastatic colorectal cancer (mCRC). Among activating mutations downstream of EGFR, the KRAS mutation, which is present in 30–45 % of CRC patients, has shown to be a predictive biomarker of resistance to anti-EGFR antibody therapy based on Caucasian studies.

Methods

Forty-three chemotherapy-refractory Japanese patients with mCRC were treated with cetuximab monotherapy or cetuximab plus irinotecan. KRAS, BRAF, and PIK3CA mutational status of tumors was assessed. The association between mutational status and treatment outcome was evaluated.

Results

Of 43 tumors, KRAS, BRAF, and PIK3CA mutations were identified in 12 (27.9 %), 2 (4.7 %), and 2 (4.7 %) tumors, respectively. The wild-type KRAS subgroup showed better clinical outcomes than the mutant KRAS subgroup in terms of response rate (RR) (31.3 % vs. 0 %, P = 0.034) and progression-free survival (PFS) (5.1 vs. 3.0 months, P = 0.017). No responder to treatment was shown in 16 (37.2 %) patients with tumors harboring mutations in any one of the three genes (KRAS, BRAF, and PIK3CA). The wild-type subgroup without any mutations in KRAS, BRAF, and PIK3CA had a better RR (37.0 %) and PFS (6.4 months) than did the wild-type KRAS subgroup.

Conclusion

Our data indicated that KRAS status is predictive of cetuximab response in the Japanese population. The additional analysis of BRAF and PIK3CA genes in wild-type KRAS patients could improve selection of patients who are most likely to benefit from anti-EGFR antibody therapy.     

The identification of KRAS mutations at codon 12 in plasma DNA is not a prognostic factor in advanced non-small cell lung cancer patients

Background

Qualitative analysis of circulating DNA in the blood is a promising non-invasive diagnostic and prognostic tool. Our aim was to study the association between the presence of KRAS mutations at codon 12 and several clinical variables in advanced non-small cell lung cancer (NSCLC) patients.

Methods

We examined 308 stage IIIB and IV NSCLC patients who were treated with cisplatin and docetaxel. Blood samples were collected before chemotherapy, and circulating DNA was extracted from the plasma using commercial adsorption columns. The KRAS mutational status was determined by an RT-PCR method that is based on allelic discrimination.

Results

The median age of the patients was 60 years [31-80], 84% were male, 98% had a performance status of 0-1 and 84% of the patients were in stage IV. The histological subtypes were as follows: 30% squamous cell carcinoma (SCC), 51% adenocarcinoma (ADC) and 19% others. Of the 277 response-evaluated patients, 1% achieved a complete response (CR), 26% achieved a partial response (PR), 34% had stable disease (SD) and 39% had progressive disease (PD). Additionally, 27 (8.8%) patients had KRAS mutations; 26 had a KRAS codon 12 TGT mutation, and 1 had a codon 12 GTT mutation. Plasmatic KRAS mutations were found in patients presenting SCC or ADC. Patients with KRAS mutations in plasma DNA had a median progression free survival (PFS) of 5.77 months [3.39-8.14], whereas for patients with wild-type (wt) KRAS, the PFS was 5.43 months [4.65-6.22] (p = 0.277). The median overall survival (OS) in KRAS-mutated patients was 9.07 months [4.43-13.70] vs 10.03 months [8.80-11.26] in wt patients (p = 0.514).

Conclusions

In advanced NSCLC patients, there were no significant differences between patients with or without KRAS mutations in plasma-free DNA with respect to the baseline characteristics, response rates, PFS or OS.