Alfredo Falcone

Regorafenib monotherapy for previously treated metastatic colorectal cancer (CORRECT): an international, multicentre, randomised, placebo-controlled, phase 3 trial

BACKGROUND No treatment options are available for patients with metastatic colorectal cancer that progresses after all approved standard therapies, but many patients maintain a good performance status and could be candidates for further therapy. An international phase 3 trial was done to assess the multikinase inhibitor regorafenib in these patients. METHODS We did this trial at 114 centres in 16 countries. Patients with documented metastatic colorectal cancer and progression during or within 3 months after the last standard therapy were randomised (in a 2:1 ratio; by computer-generated randomisation list and interactive voice response system; preallocated block design (block size six); stratified by previous treatment with VEGF-targeting drugs, time from diagnosis of metastatic disease, and geographical region) to receive best supportive care plus oral regorafenib 160 mg or placebo once daily, for the first 3 weeks of each 4 week cycle. The primary endpoint was overall survival. The study sponsor, participants, and investigators were masked to treatment assignment. Efficacy analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT01103323. FINDINGS Between April 30, 2010, and March 22, 2011, 1052 patients were screened, 760 patients were randomised to receive regorafenib (n=505) or placebo (n=255), and 753 patients initiated treatment (regorafenib n=500; placebo n=253; population for safety analyses). The primary endpoint of overall survival was met at a preplanned interim analysis; data cutoff was on July 21, 2011. Median overall survival was 6·4 months in the regorafenib group versus 5·0 months in the placebo group (hazard ratio 0·77; 95% CI 0·64-0·94; one-sided p=0·0052). Treatment-related adverse events occurred in 465 (93%) patients assigned regorafenib and in 154 (61%) of those assigned placebo. The most common adverse events of grade three or higher related to regorafenib were hand-foot skin reaction (83 patients, 17%), fatigue (48, 10%), diarrhoea (36, 7%), hypertension (36, 7%), and rash or desquamation (29, 6%). INTERPRETATION Regorafenib is the first small-molecule multikinase inhibitor with survival benefits in metastatic colorectal cancer which has progressed after all standard therapies. The present study provides evidence for a continuing role of targeted treatment after disease progression, with regorafenib offering a potential new line of therapy in this treatment-refractory population. FUNDING Bayer HealthCare Pharmaceuticals.

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.

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.

PTEN Expression and KRAS Mutations on Primary Tumors and Metastases in the Prediction of Benefit From Cetuximab Plus Irinotecan for Patients With Metastatic Colorectal Cancer

PURPOSE PTEN, AKT, and KRAS are epidermal growth factor receptor (EGFR) downstream regulators. KRAS mutations confer resistance to cetuximab. This retrospective study investigated the role of PTEN loss, AKT phosphorylation, and KRAS mutations on the activity of cetuximab plus irinotecan in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS A cohort of patients with irinotecan-refractory mCRC who were treated with cetuximab plus irinotecan was tested for PTEN immunoreactivity (ie, immunohistochemistry; IHC), pAKT IHC, and KRAS mutations. Analyses were performed both on primary tumors and on related metastases, and the association among IHC, mutational results, and treatment outcomes was investigated. RESULTS One-hundred two patients were eligible. Ninety-six primary tumors, 59 metastases, and 53 paired samples were available. Forty-nine primary tumors (58% of assessable samples) had a preserved PTEN expression (PTEN-positive), whereas 35 (40% of assessable samples) were pAKT-positive. Levels of concordance between primary tumors and metastases were 60%, 68%, and 95% for PTEN, pAKT, and KRAS, respectively. PTEN status on primary tumors and pAKT status both on primary tumors and on metastases did not predict response or progression-free survival (PFS). On metastases, 12 (36%) of 33 patients with PTEN-positive tumors were responders compared with one (5%) of 22 who had PTEN-negative tumors (P = .007). The median PFS of patients with PTEN-positive metastases was 4.7 months compared with 3.3 months for those with PTEN-negative metastases (hazard ratio [HR], 0.49; P = .005). Patients with PTEN-positive metastases and KRAS wild type had longer PFS compared with other patients (5.5 months v 3.8 months; HR, 0.42; P = .001). CONCLUSION PTEN loss in metastases may be predictive of resistance to cetuximab plus irinotecan. The combination of PTEN IHC and KRAS mutational analyses could help to identify a subgroup of patients with mCRC who have higher chances of benefiting from EGFR inhibition.

ESMO consensus guidelines for the management of patients with metastatic colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies in Western countries. Over the last 20 years, and the last decade in particular, the clinical outcome for patients with metastatic CRC (mCRC) has improved greatly due not only to an increase in the number of patients being referred for and undergoing surgical resection of their localised metastatic disease but also to a more strategic approach to the delivery of systemic therapy and an expansion in the use of ablative techniques. This reflects the increase in the number of patients that are being managed within a multidisciplinary team environment and specialist cancer centres, and the emergence over the same time period not only of improved imaging techniques but also prognostic and predictive molecular markers. Treatment decisions for patients with mCRC must be evidence-based. Thus, these ESMO consensus guidelines have been developed based on the current available evidence to provide a series of evidence-based recommendations to assist in the treatment and management of patients with mCRC in this rapidly evolving treatment setting.

Initial Therapy with FOLFOXIRI and Bevacizumab for Metastatic Colorectal Cancer

BACKGROUND A fluoropyrimidine plus irinotecan or oxaliplatin, combined with bevacizumab (a monoclonal antibody against vascular endothelial growth factor), is standard first-line treatment for metastatic colorectal cancer. Before the introduction of bevacizumab, chemotherapy with fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) showed superior efficacy as compared with fluorouracil, leucovorin, and irinotecan (FOLFIRI). In a phase 2 study, FOLFOXIRI plus bevacizumab showed promising activity and an acceptable rate of adverse effects. METHODS We randomly assigned 508 patients with untreated metastatic colorectal cancer to receive either FOLFIRI plus bevacizumab (control group) or FOLFOXIRI plus bevacizumab (experimental group). Up to 12 cycles of treatment were administered, followed by fluorouracil plus bevacizumab until disease progression. The primary end point was progression-free survival. RESULTS The median progression-free survival was 12.1 months in the experimental group, as compared with 9.7 months in the control group (hazard ratio for progression, 0.75; 95% confidence interval [CI], 0.62 to 0.90; P=0.003). The objective response rate was 65% in the experimental group and 53% in the control group (P=0.006). Overall survival was longer, but not significantly so, in the experimental group (31.0 vs. 25.8 months; hazard ratio for death, 0.79; 95% CI, 0.63 to 1.00; P=0.054). The incidences of grade 3 or 4 neurotoxicity, stomatitis, diarrhea, and neutropenia were significantly higher in the experimental group. CONCLUSIONS FOLFOXIRI plus bevacizumab, as compared with FOLFIRI plus bevacizumab, improved the outcome in patients with metastatic colorectal cancer and increased the incidence of some adverse events. (Funded by the Gruppo Oncologico Nord Ovest and others; ClinicalTrials.gov number, NCT00719797.).

Clonal evolution and resistance to EGFR blockade in the blood of colorectal cancer patients

Colorectal cancers (CRCs) evolve by a reiterative process of genetic diversification and clonal evolution. The molecular profile of CRC is routinely assessed in surgical or bioptic samples. Genotyping of CRC tissue has inherent limitations; a tissue sample represents a single snapshot in time, and it is subjected to spatial selection bias owing to tumor heterogeneity. Repeated tissue samples are difficult to obtain and cannot be used for dynamic monitoring of disease progression and response to therapy. We exploited circulating tumor DNA (ctDNA) to genotype colorectal tumors and track clonal evolution during treatment with the epidermal growth factor receptor (EGFR)-specific antibodies cetuximab or panitumumab. We identified alterations in ctDNA of patients with primary or acquired resistance to EGFR blockade in the following genes: KRAS, NRAS, MET, ERBB2, FLT3, EGFR and MAP2K1. Mutated KRAS clones, which emerge in blood during EGFR blockade, decline upon withdrawal of EGFR-specific antibodies, indicating that clonal evolution continues beyond clinical progression. Pharmacogenomic analysis of CRC cells that had acquired resistance to cetuximab reveals that upon antibody withdrawal KRAS clones decay, whereas the population regains drug sensitivity. ctDNA profiles of individuals who benefit from multiple challenges with anti-EGFR antibodies exhibit pulsatile levels of mutant KRAS. These results indicate that the CRC genome adapts dynamically to intermittent drug schedules and provide a molecular explanation for the efficacy of rechallenge therapies based on EGFR blockade.

MicroRNA-21 in Pancreatic Cancer: Correlation with Clinical Outcome and Pharmacologic Aspects Underlying Its Role in the Modulation of Gemcitabine Activity

MicroRNA-21 (miR-21) was reported to be overexpressed and contributes to invasion and gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to evaluate whether miR-21 expression was associated with the overall survival (OS) of PDAC patients treated with gemcitabine and to provide mechanistic insights for new therapeutic targets. miR-21 expression was evaluated in cells (including 7 PDAC cell lines, 7 primary cultures, fibroblasts, and a normal pancreatic ductal cell line) and tissues (neoplastic specimens from 81 PDAC patients and normal ductal samples) isolated by laser microdissection. The role of miR-21 on the pharmacologic effects of gemcitabine was studied with a specific miR-21 precursor (pre-miR-21). Patients with high miR-21 expression had a significantly shorter OS both in the metastatic and in the adjuvant setting. Multivariate analysis confirmed the prognostic significance of miR-21. miR-21 expression in primary cultures correlated with expression in their respective tissues and with gemcitabine resistance. Pre-miR-21 transfection significantly decreased antiproliferative effects and apoptosis induction by gemcitabine, whereas matrix metalloproteinase (MMP)-2/MMP-9 and vascular endothelial growth factor expression were upregulated. Addition of inhibitors of phosphoinositide 3-kinase and mammalian target of rapamycin resulted in decrease of phospho-Akt and prevented pre-miR-21-induced resistance to the proapoptotic effects of gemcitabine. miR-21 expression correlated with outcome in PDAC patients treated with gemcitabine. Modulation of apoptosis, Akt phosphorylation, and expression of genes involved in invasive behavior may contribute to the role of miR-21 in gemcitabine chemoresistance and to the rational development of new targeted combinations.

Randomized Trial of TAS-102 for Refractory Metastatic Colorectal Cancer

BACKGROUND Early clinical trials conducted primarily in Japan have shown that TAS-102, an oral agent that combines trifluridine and tipiracil hydrochloride, was effective in the treatment of refractory colorectal cancer. We conducted a phase 3 trial to further assess the efficacy and safety of TAS-102 in a global population of such patients. METHODS In this double-blind study, we randomly assigned 800 patients, in a 2:1 ratio, to receive TAS-102 or placebo. The primary end point was overall survival. RESULTS The median overall survival improved from 5.3 months with placebo to 7.1 months with TAS-102, and the hazard ratio for death in the TAS-102 group versus the placebo group was 0.68 (95% confidence interval [CI], 0.58 to 0.81; P<0.001). The most frequently observed clinically significant adverse events associated with TAS-102 were neutropenia, which occurred in 38% of those treated, and leukopenia, which occurred in 21%; 4% of the patients who received TAS-102 had febrile neutropenia, and one death related to TAS-102 was reported. The median time to worsening performance status (a change in Eastern Cooperative Oncology Group performance status [on a scale of 0 to 5, with 0 indicating no symptoms and higher numbers indicating increasing degrees of disability] from 0 or 1 to 2 or more) was 5.7 months with TAS-102 versus 4.0 months with placebo (hazard ratio, 0.66; 95% CI, 0.56 to 0.78; P<0.001). CONCLUSIONS In patients with refractory colorectal cancer, TAS-102, as compared with placebo, was associated with a significant improvement in overall survival. (Funded by Taiho Oncology-Taiho Pharmaceutical; RECOURSE ClinicalTrials.gov number, NCT01607957.).

Pharmacogenetic Profiling in Patients With Advanced Colorectal Cancer Treated With First-Line FOLFOX-4 Chemotherapy

PURPOSE The objective is to investigate whether polymorphisms with putative influence on fluorouracil/oxaliplatin activity are associated with clinical outcomes of patients with advanced colorectal cancer treated with first-line oxaliplatin, folinic acid, and fluorouracil palliative chemotherapy. MATERIALS AND METHODS Consecutive patients were prospectively enrolled onto medical oncology units in Central Italy. Patients were required to have cytologically/histologically confirmed metastatic disease with at least one measurable lesion. Peripheral blood samples were used for genotyping 12 polymorphisms in thymidylate synthase, methylenetetrahydrofolate reductase, xeroderma pigmentosum group D (XPD), excision repair cross complementing group 1 (ERCC1), x-ray cross complementing group 1, x-ray cross complementing protein 3, glutathione S-transferases (GSTs) genes. The primary end point of the study was to investigate the association between genotypes and progression-free survival (PFS). RESULTS In 166 patients, ERCC1-118 T/T, XPD-751 A/C, and XPD-751 C/C genotypes were independently associated with adverse PFS. The presence of two risk genotypes (ERCC1-118 T/T combined with either XPD-751 A/C or XPD-751 C/C) occurred in 50 patients (31%). This profiling showed an independent role for unfavorable PFS with a hazard ratio of 2.84% and 95% CI of 1.47 to 5.45 (P = .002). Neurotoxicity was significantly associated with GSTP1-105 A/G. Carriers of the GSTP1-105 G/G genotype were more prone to suffer from grade 3 neurotoxicity than carriers of GSTP1-105 A/G and GSTP1-105 A/A genotypes. CONCLUSION A pharmacogenetic approach may be an innovative strategy for optimizing palliative chemotherapy in patients with advanced colorectal cancer. These findings deserve confirmation in additional prospective studies.