FOLFOXIRI in combination with panitumumab as first-line treatment in quadruple wild-type (KRAS, NRAS, HRAS, BRAF) metastatic colorectal cancer patients: a phase II trial by the Gruppo Oncologico Nord Ovest (GONO)

FOLFOXIRI plus cetuximab as conversion therapy for unresectable RAS/BRAF wild-type left-sided colorectal cancer with liver-limited metastases: a prospective dual-center pilot study

Purpose

To explore the efficacy and safety of FOLFOXIRI plus cetuximab regimen as conversion therapy for patients with unresectable RAS/BRAF wild-type colorectal liver-limited metastases (CLM).

Patients and methods

This was a dual-center, phase II trial with the rate of no evidence of disease (NED) achieved as the primary endpoint. All enrolled patients with initially unresectable left-sided RAS/BRAF wild-type colorectal liver-limited metastases received a modified FOLFOXIRI plus cetuximab regimen as conversion therapy.

Results

Between October 2019 and October 2021, fifteen patients were enrolled. Nine patients (60%) achieved NED. The overall response rate (ORR) was 92.9%, and the disease control rate (DCR) was 100%. The median relapse-free survival (RFS) was 9 (95% CI: 0-20.7) months. The median progression-free survival (PFS) was 13.0 months (95% CI: 5.7-20.5), and the median overall survival (OS) was not reached. The most frequently occurring grade 3-4 adverse events were neutropenia (20%), peripheral neurotoxicity (13.3%), diarrhea (6.7%), and rash acneiform (6.7%).

Conclusion

The FOLFOXIRI plus cetuximab regimen displayed tolerable toxicity and promising anti-tumor activity in terms of the rate of NED achieved and response rate in patients with initially unresectable left-sided RAS/BRAF wild-type CLM. This regimen merits further investigation.

The effective combination therapies with irinotecan for colorectal cancer

Colorectal cancer is the third most common type of cancer worldwide and has become one of the major human disease burdens. In clinical practice, the treatment of colorectal cancer has been closely related to the use of irinotecan. Irinotecan combines with many other anticancer drugs and has a broader range of drug combinations. Combination therapy is one of the most important means of improving anti-tumor efficacy and overcoming drug resistance. Reasonable combination therapy can lead to better patient treatment options, and inappropriate combination therapy will increase patient risk. For the colorectal therapeutic field, the significance of combination therapy is to improve the efficacy, reduce the adverse effects, and improve the ease of treatment. Therefore, we explored the clinical advantages of its combination therapy based on mechanism or metabolism and reviewed the rationale basis and its limitations in conducting exploratory clinical trials on irinotecan combination therapy, including the results of clinical trials on the combination potentiation of cytotoxic drugs, targeted agents, and herbal medicine. We hope that these can evoke more efforts to conduct irinotecan in the laboratory for further studies and evaluations, as well as the possibility of more in-depth development in future clinical trials.

Efficacy and quality of life for FOLFOX/bevacizumab +/- irinotecan in first-line metastatic colorectal cancer-final results of the AIO CHARTA trial

BACKGROUND

FOLFOXIRI plus bevacizumab has demonstrated benefits for metastatic colorectal cancer (mCRC) patients. However, challenges arise in its clinical implementation due to expected side effects and a lack of stratification criteria.

METHODS

The AIO "CHARTA" trial randomised mCRC patients into clinical Group 1 (potentially resectable), 2 (unresectable/risk of rapid progression), or 3 (asymptomatic). They received FOLFOX/bevacizumab +/- irinotecan. The primary endpoint was the 9-month progression-free survival rate (PFSR@9). Secondary endpoints included efficacy in stratified groups, QoL, PFS, OS, ORR, secondary resection rate, and toxicity.

RESULTS

The addition of irinotecan to FOLFOX/bevacizumab increased PFSR@9 from 56 to 67%, meeting the primary endpoint. The objective response rate was 61% vs. 69% (P = 0.21) and median PFS was 10.3 vs. 12 months (HR 0.83; P = 0.17). The PFS was (11.4 vs. 12.9 months; HR 0.83; P = 0.46) in potentially resectable patients, with a secondary resection rate of 37% vs. 51%. Moreover, Group 3 (asymptomatic) patients had a PFS of 11.1 vs. 16.1 months (HR 0.6; P = 0.14). The addition of irinotecan did not diminish QoL.

CONCLUSION

The CHARTA trial, along with other studies, confirms the efficacy and tolerability of FOLFOXIRI/bevacizumab as a first-line treatment for mCRC. Importantly, clinical stratification may lead to its implementation.

TRIAL REGISTRATION

The trial was registered as NCT01321957.

Triplet-drug chemotherapy combined with anti-EGFR antibody as an effective therapy for patients with initially unresectable metastatic colorectal cancer: a meta-analysis

The meta-analysis aimed to assess the clinical efficacy of chemotherapeutic triplet-drug regimen combined with anti-EGFR antibody in patients with initially unresectable metastatic colorectal cancer (mCRC). A systematic literature search was performed in PubMed Publisher. Studies evaluating FOLFOXIRI combine with panitumumab or cetuximab as the therapy for initially unresectable mCRC were included. The primary outcome was objective response rate (ORR) and rate of R0 resections. The secondary outcomes included overall survival (OS), progression-free survival (PFS), and grades 3 or 4 adverse events. R software (version 4.0.2) and RevMan (version 5.3) were used to analyze the extracted data. The studies included were published between 2010 and 2021, involving four single-arm phase II trials and two randomized phase II trials. A total of 6 studies with 282 patients were included. The data showed a significant benefit for the FOLFOXIRI + anti-EGFR antibody arm compared with FOLFOXIRI arm (RR 1.33; 95% CI, 1.13-1.58; I2 = 0%, P < 0.05). The pooled ORR and pooled rate of R0 resection in patients who receiving FOLFOXIRI + anti-EGFR antibody were 85% (95% CI, 0.78-0.91; I2 = 58%) and 42% (95% CI, 0.32-0.53; I2 = 62%), respectively. The range of median PFS between all the six studies was 9.5-15.5 months, with weighted pooled median PFS mean 11.7 months. The range of median OS between all the four studies was 24.7-37 months, with weighted pooled median PFS mean 31.9 months. The common grades 3 and 4 adverse events were diarrhea and neutropenia. Our findings show that triplet-drug chemotherapy (FOLFOXIRI) combined with anti-EGFR antibody (panitumumab or cetuximab) represents a very effective therapeutic combination associated with a significant ORR and R0 rection rate for patients with molecularly unselected and surgically unresectable metastatic CRC.

Progress of research on molecular targeted therapies for colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies, accounting for approximately 10% of global cancer incidence and mortality. Approximately 20% of patients with CRC present metastatic disease (mCRC) at the time of diagnosis. Moreover, up to 50% of patients with localized disease eventually metastasize. mCRC encompasses a complex cascade of reactions involving multiple factors and processes, leading to a diverse array of molecular mechanisms. Improved comprehension of the pathways underlying cancer cell development and proliferation, coupled with the accessibility of relevant targeted agents, has propelled advancements in CRC treatment, ultimately leading to enhanced survival rates. Mutations in various pathways and location of the primary tumor in CRC influences the efficacy of targeted agents. This review summarizes available targeted agents for different CRC pathways, with a focus on recent advances in anti-angiogenic and anti-epidermal growth factor receptor agents, BRAF mutations, and human epidermal growth factor receptor 2-associated targeted agents.

Comparison of Neoadjuvant Systemic Chemotherapy Protocols for the Curative-Intent Management of Peritoneal Metastases from Colorectal Cancer, Regarding Morphological Response, Pathological Response, and Long-Term Outcomes: A Retrospective Study

BACKGROUND

Selected patients with colorectal cancer peritoneal metastases (CRPM) could be offered a curative-intent strategy based on complete cytoreductive surgery (CRS), potentially combined with hyperthermic intraperitoneal chemotherapy (HIPEC) and perioperative systemic chemotherapy. The impact of different neoadjuvant systemic chemotherapy (NACT) regimens remains unclear due to a lack of comparative data.

METHODS

Consecutive CRPM patients from a monocentric database who were treated with complete CRS after single-line NACT were included in this study. Chemotherapy regimens were tailored as a doublet drug (FOLFOX/FOLFIRI) with/without targeted therapy (anti-epidermal growth factor receptor/bevacizumab) and triplet-drug combination (FOLFIRINOX). Morphological response (MR) was assessed using the Response Evaluation Criteria in Solid Tumors criteria, and pathological response (PR) was assessed using the Peritoneal Regression Grading Score (PRGS). Long-term oncologic outcomes were compared.

RESULTS

The cohort comprised 388 patients, including 127, 202, and 59 patients in the doublet, doublet + targeted, and triplet groups, respectively. MR rates were higher in the triplet (68.0%) and doublet + targeted groups (64.2%) when compared with the doublet group (42.4%, p = 0.003). Complete and major PRs were observed in 13.6% and 32.0% of patients, respectively. Higher MR rates were observed after doublet + targeted or triplet regimens, while no difference was observed for PR rates. In multivariate analysis, FOLFIRINOX was independently associated with better overall survival (hazard ratio 0.49, 95% confidence interval 0.25-0.96; p = 0.037). FOLFIRINOX also resulted in a higher rate of severe postoperative complications.

CONCLUSIONS

In this retrospective study, a FOLFIRINOX regimen as NACT seemed to result in better long-term outcomes for CRPM patients after complete CRS/HIPEC, although with higher morbidity. Prospective studies are needed, including groups without NACT and those with FOLFIRINOX + bevacizumab.

The optimal first-line treatment for patients with left-sided RAS wild-type metastatic colorectal cancer: Double-drug regimen or triple-drug regimen therapy

There are many treatments for metastatic colorectal cancer (mCRC). Among them, uncertainty remains especially concerning the clinical benefit of different regimens for left-sided RAS wild-type (WT) mCRC in the triple-drug therapy era. No studies have been conducted to answer this critical clinical issue. We performed a comprehensive analysis of published data and real-world data. First, we conducted analyses of the published trials to show the landscape of efficacy and safety in the treatments of left-sided RAS WT mCRC. Then, we initiated a multicenter real-world study as the validation dataset. This study included six published randomized controlled trials (RCTs) and a total of 1925 patients. The double-drug regimen plus cetuximab/panitumumab (D + C/P) achieved the longest overall survival (OS) in patients with left-sided mCRC (HR = 0.74, 95%CI: 0.57–0.98), while triple-drug regimen with bevacizumab (T + B, HR = 1.1, 95%CI: 0.63–2.0), compared with double-drug with bevacizumab (D + B). The D + C/P had the highest overall response rate (ORR) in patients with left-sided mCRC (OR = 1.8, 95%CI: 0.89–3.8), while T + B (OR = 1.8, 95%CI: 0.70–4.8), compared with D + B. The multicenter real-world cohort showed the double-drug regimen plus cetuximab had longer progression-free survival (PFS) in left-sided mCRC patients than the triple-drug regimen with bevacizumab. The safety analysis showed the incidence of the adverse events (grade≥3) in the triple-drug therapy plus bevacizumab was higher than that in the double-drug therapy plus cetuximab/panitumumab. This work demonstrates the ranking of three regimens for therapeutic efficacy and safety in patients with left-sided RAS WT mCRC. The double-drug regimen plus cetuximab/panitumumab appears more effective and safer than double-drug and triple-drug based regimens with bevacizumab. Further trials and cohort analyses on this topic would increase confidence in these results.

Efficacy and safety of triplet chemotherapy plus anti-EGFR agents in metastatic colorectal cancer: a systematic review and meta-analysis

Background

To date, the optimal treatment for potentially resectable metastatic colorectal cancer (mCRC) patients has yet to be determined. Encouraging results have been reported in studies exploring the efficacy of triplet chemotherapy plus anti-epidermal growth factor receptor (anti-EGFR) target agents. Thus, we conducted a meta-analysis to evaluate the efficacy and safety of triplet chemotherapy plus anti-EGFR target agents.

Methods

We systematically searched the PubMed, Embase, and Web of Science databases from December 2004 to October 2021 for studies examining the efficacy of triplet chemotherapy plus anti-EGFR target agents in mCRC patients. The primary outcomes were the objective response rate (ORR) and R0 resection rate (R0RR), and the secondary outcomes were median progression-free survival (mPFS), median overall survival (mOS), and toxicity. Data were analyzed with R software 4.1.2.

Results

Fourteen studies comprising 762 patients with mCRC were included in this meta-analysis. Analysis with a random effects model revealed that after treatment with triplet chemotherapy plus anti-EGFR target agents, the pooled ORR was 82% (95% CI= 76–88%, I2= 76%), and the pooled R0RR of colorectal liver metastasis (CLM) was 59% (95% CI= 49–68%, I2= 60%). The mPFS ranged from 9.5 to 17.8 months, and the mOS ranged from 24.7 to 62.5 months. A total of 648 grade 3 or 4 adverse events were reported; the most commonly reported events were diarrhea (174/648), neutropenia (157/648), and skin toxicity (95/648), which had pooled prevalence rates of 29% (95% CI= 20–39%, I2= 84%), 28% (95% CI= 20–37%, I2= 77%), and 17% (95% CI= 11–24%, I2= 66%), respectively.

Conclusions

Triplet chemotherapy plus anti-EGFR agents therapy seems to be capable of increasing the ORR of mCRC patients and the R0RR of CLM patients. The toxicity of this treatment is manageable. High-quality randomized controlled trial (RCT) studies are required for further validation.

Upfront Modified Fluorouracil, Leucovorin, Oxaliplatin, and Irinotecan Plus Panitumumab Versus Fluorouracil, Leucovorin, and Oxaliplatin Plus Panitumumab for Patients With RAS/BRAF Wild-Type Metastatic Colorectal Cancer: The Phase III TRIPLETE Study by GONO

To verify whether the intensification of the upfront chemotherapy backbone with a modified schedule of modified fluorouracil, leucovorin, oxaliplatin, and irinotecan (mFOLFOXIRI) increases the activity of fluorouracil, leucovorin, and oxaliplatin when both regimens are combined with panitumumab as initial treatment for RAS and BRAF wild-type (wt) metastatic colorectal cancer (mCRC).

Triplet chemotherapy in combination with anti-EGFR agents for the treatment of metastatic colorectal cancer: Current evidence, advances, and future perspectives

Doublet or triplet chemotherapy regimens in combination with anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibodies (mAb), such as cetuximab or panitumumab, or the anti-vascular endothelial growth factor mAb bevacizumab, are the current recommended standard of care therapies for unresectable metastatic colorectal cancer (mCRC). While the recommended dosing schedule for the triplet chemotherapy regimen with 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI) in combination with bevacizumab is well established, the optimal dosing of FOLFOXIRI in combination with anti-EGFR agents is unknown. Several randomized, phase 3 clinical trials of patients with mCRC have demonstrated improved survival and response rates with FOLFOXIRI, alone or when combined with bevacizumab, compared with doublet chemotherapy regimens. Trials of anti-EGFR agents in combination with FOLFOXIRI have also shown promising results. In this review, we summarize the emerging evidence regarding the safety and efficacy of anti-EGFR agents in combination with triplet chemotherapy regimens and discuss the potential for this combination as a future treatment option for patients with RAS-wild-type mCRC.

Cetuximab versus bevacizumab maintenance following prior 8-cycle modified FOLFOXIRI plus cetuximab in Asian postmenopausal women with treatment-naive KRAS and BRAF wild-type metastatic colorectal cancer

OBJECTIVE

To assess the efficacy and safety of cetuximab (CE) versus bevacizumab (BE) maintenance treatment after prior 8-cycle modified 5-fluorouracil, folinate, oxaliplatin, and irinotecan (FOLFOXIRI) plus CE induction therapy in treatment-naive KRAS and BRAF wild-type (wt) metastatic colorectal cancer (mCRC).

METHODS

From 2012 to 2017, prospectively maintained databases were reviewed to assess Asian postmenopausal women with treatment-naive KRAS and BRAF wt mCRC who underwent modified FOLFOXIRI plus CE induction therapy, followed by CE or BE maintenance until disease progression or death. Co-primary clinical endpoints were progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 222 women were included (CE n = 110 and BE n = 112). At a median follow-up of 27.0 months (interquartile range, 6.5-38.6 months), median PFS was 21.9 months (95% confidence interval [CI] 16.4-24.4) and 17.7 months (95% CI 11.3-19.0) for CE and BE groups, respectively (hazard ratio [HR] 0.31, 95% CI 0.15-0.46); median OS was 26.0 months (95% CI 23.4-28.7) and 22.7 months (95% CI 21.2-24.3) for CE and BE groups, respectively (HR 0.22, 95% CI 0.11-0.37).

CONCLUSIONS

CE maintenance treatment is more poorly tolerated but has a slightly more modest survival benefit compared with BE maintenance treatment in mCRC.

Cetuximab versus bevacizumab following prior FOLFOXIRI and bevacizumab in postmenopausal women with advanced KRAS and BRAF wild-type colorectal cancer: a retrospective study

BACKGROUND

An upgraded understanding of factors (sex/estrogen) associated with survival benefit in advanced colorectal carcinoma (CRC) could improve personalised management and provide innovative insights into anti-tumour mechanisms. The aim of this study was to assess the efficacy and safety of cetuximab (CET) versus bevacizumab (BEV) following prior 12 cycles of fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus BEV in postmenopausal women with advanced KRAS and BRAF wild-type (wt) CRC.

METHODS

Prospectively maintained databases were reviewed from 2013 to 2017 to assess postmenopausal women with advanced KRAS and BRAF wt CRC who received up to 12 cycles of FOLFOXIRI plus BEV inductive treatment, followed by CET or BEV maintenance treatment. The primary endpoints were overall survival (OS), progression-free survival (PFS), response rate. The secondary endpoint was the rate of adverse events (AEs).

RESULTS

At a median follow-up of 27.0 months (IQR 25.1-29.2), significant difference was detected in median OS (17.7 months [95% confidence interval [CI], 16.2-18.6] for CET vs. 11.7 months [95% CI, 10.4-12.8] for BEV; hazard ratio [HR], 0.63; 95% CI, 0.44-0.89; p=0.007); Median PFS was 10.7 months (95% CI, 9.8-11.3) for CET vs. 8.4 months (95% CI, 7.2-9.6) for BEV (HR, 0.67; 95% CI 0.47-0.94; p=0.02). Dose reduction due to intolerable AEs occurred in 29 cases (24 [24.0%] for CET vs. 5 [4.8%] for BEV; p< 0.001).

CONCLUSIONS

CET tends to be superior survival benefit when compared with BEV, with tolerated AEs.

A triplet combination of FOLFOXIRI plus cetuximab as first-line treatment in RAS wild-type, metastatic colorectal cancer: a dose-escalation phase Ib study

BACKGROUND

The triplet-agent (5-fluorouracil/leucovorin, oxaliplatin, and irinotecan; FOLFOXIRI) combined with an anti-epidermal growth factor receptor antibody as a first-line treatment of metastatic colorectal cancer (mCRC) has shown promising results in Western trials. This phase Ib study assessed the safety of FOLFOXIRI plus cetuximab in Japanese patients with RAS wild-type mCRC.

METHODS

Patients with previously untreated RAS wild-type mCRC received weekly cetuximab (400 mg/m² at week 1 and subsequently 250 mg/m²) plus FOLFOXIRI that consisted of irinotecan (100, 120, and 150 mg/m² defined as dose levels 0, 1, and 2), followed by oxaliplatin 85 mg/m² and l-leucovorin 200 mg/m² and then 5-fluorouracil 2400 mg/m². The dose level of irinotecan was escalated starting at dose level 1 in a 3 + 3 manner. The primary endpoint was to determine the maximum-tolerated dose (MTD) and the recommended phase-2 dose (RP2D). Secondary endpoints included safety, overall response rate (ORR), progression-free survival (PFS) and overall survival (OS).

RESULTS

Nine patients were enrolled. The MTD was not reached at dose level 2 and the RP2D was 150 mg/m² irinotecan. The most frequent grade 3/4 adverse events were neutropenia (44%), fatigue (11%), paronychia (22%), and acneiform rash (11%). No dose-limiting toxicities occurred in any of the enrolled patients. No treatment-related death was observed. The ORR was 89% (95% confidence interval 52-100%).

CONCLUSION

The safety profile of the combination of cetuximab and FOLFOXIRI was acceptable and promising anti-tumor activity was demonstrated, supporting further study in patients with RAS wild-type mCRC.

Modified FOLFOXIRI With or Without Cetuximab as Conversion Therapy in Patients with RAS/BRAF Wild-Type Unresectable Liver Metastases Colorectal Cancer: The FOCULM Multicenter Phase II Trial

PURPOSE

This trial evaluated the addition of cetuximab to a modified FOLFOXIRI (mFOLFOXIRI: 5-fluorouracil/folinic acid, oxaliplatin, irinotecan) as conversion therapy in a two-group, nonrandomized, multicenter, phase II trial in patients with initially technically unresectable colorectal liver-limited metastases (CLM) and BRAF/RAS wild-type.

PATIENTS AND METHODS

Patients were enrolled to receive cetuximab (500 mg/m² ) plus mFOLFOXIRI (oxaliplatin 85 mg/m² , irinotecan 165 mg/m² , folinic acid 400 mg/m² , 5-fluorouracil 2,800 mg/m² 46-hour infusion, every 2 weeks) (the cetuximab group) or the same regimen of mFOLFOXIRI alone (the control group), in a 2:1 ratio allocation. The primary endpoint was the rate of no evidence of disease (NED) achieved. Secondary endpoints included resection rate, objective response rate (ORR), survival, and safety.

RESULTS

Between February 2014 and July 2019, 117 patients were registered for screening at six centers in China, and 101 of these were enrolled (67 cetuximab group, 34 control group). The rate of NED achieved was 70.1% in the cetuximab group and 41.2% in the control group (difference 29.0%; 95% confidence interval [CI], 9.1%-48.8%; p = .005). Patients in the cetuximab group had improved ORR (95.5% vs. 76.5%; difference 19.1%; 95% CI, 17.4%-36.4%; p = .010) compared with those in control group. Progression-free survival and overall survival showed the trend to favor the cetuximab group. The incidence of grade 3 and 4 adverse events was similar in the two groups.

CONCLUSION

Addition of cetuximab to mFOLFOXIRI improved the rate of NED achieved. This combination could be an option of conversion regimen for molecularly selected patients with initially technically unresectable CLM.

IMPLICATIONS FOR PRACTICE

This trial evaluated the addition of cetuximab to a modified FOLFOXIRI as conversion therapy in a phase II trial in patients with initially technically unresectable colorectal liver-limited metastases and BRAF/RAS wild-type. The rate of no evidence of disease achieved was 70.1% in the cetuximab plus modified FOLFOXIRI group and 41.2% in the modified FOLFOXIRI group. Objective response rates, overall survival, and progression-free survival were improved in the cetuximab group when compared with the modified FOLFOXIRI group. Addition of cetuximab to modified FOLFOXIRI increased the rate of no evidence of disease achieved, and this combination could be an option of conversion regimen for molecularly selected patients with initially technically unresectable colorectal liver-limited metastasis.

Efficacy and Safety of Modified FOLFOXIRI+α in the Treatment of Advanced and Recurrent Colorectal Cancer: A Single-center Experience

Objective In the treatment of advanced and recurrent colorectal cancer (ARCC), FOLFOXIRI regimens have been proven to be significantly superior to FOLFIRI in terms of the progression-free survival (PFS), response rate (RR), and overall survival (OS). Furthermore, the Tribe trial showed that the RR and PFS rates in patients who received bevacizumab (Bmab) +FOLFOXIRI were superior to those in patients treated with Bmab+FOLFIRI. A phase III trial of panitumumab (Pmab) +FOLFOXIRI is currently ongoing. A modified FOLFOXIRI regimen is also widely used to reduce adverse events. In our department, we introduced modified FOLFOXIRI+α (mFOLFOXIRI+α) in 2015. The present study reviewed the efficacy and safety of mFOLFOXIRI+α. Methods Eligible patients were retrospectively reviewed, and their results were compared to those of patients treated with other regimens (OTHERS) (n=134) to demonstrate the efficacy of this treatment. Patients: Between February 2015 and November 2018, 12 patients with ARCC (male/female=6/6; average age, 60.7 years old) received mFOLFOXIRI+α (Bmab: 10, Pmab: 1, alone: 1). Results The median PFS in the mFOLFOXIRI+α and OTHERS groups was 565 and 322 days, respectively (p=0.0544). The RR in the mFOLFOXIRI+α and OTHERS groups was 66.7% and 31.3%, respectively (p=0.0135). The conversion rate (Conv R) in the mFOLFOXIRI+α and OTHERS groups was 50.0% and 12.7%, respectively (p=0.0007). While 58% of patients treated with FOLFOXIRI+α developed grade ≥3 leukopenia, the incidence of febrile neutropenia (FN) was only 17%. In all patients with symptoms due to the tumor burden, the symptoms subsided with mFOLFOXIRI+α treatment. Conclusion Based on the RR, Conv R, and symptom palliation ability, mFOLFOXIRI+α was suggested to be a viable candidate for first-line treatment for patients with ARCC, especially those with a high tumor burden.

Cyclophilin a knokdown inhibits cell migration and invasion through the suppression of epithelial-mesenchymal transition in colorectal cancer cells

Enhanced expression of cyclophilin A (CypA) in colorectal cancer (CRC) was reported; however, how CypA influences CRC progression is not clear. Therefore, we examine the effects of CypA on CRC cell progression. Knockdown of CypA in SW480 cells significantly inhibited cell migration and invasion but had no effect on cell proliferation. In addition, upregulation of E-cadherin and downregulation of N-cadherin and Snail expression were observed by CypA knockdown. These results suggested that CypA knockdown inhibited cell migration and invasion by suppressing epithelial-mesenchymal transition. CypA knockdown was also associated with increased p38 phosphorylation, and the p38 inhibitor treatment led to increase in the number of invasive CypA-knockdown SW480 cells. Therefore, CypA may be a potential therapeutic target in preventing CRC metastasis.

Toxicity Syndromes, Patient-Related Clinical Indicator of Toxicity Burden Induced by Intensive Triplet Chemotherapy-Based Regimens in Gastrointestinal Cancers With Metastatic Disease

Background: Cancer treatments induce symptoms/signs superimposing on individual patient's clinical status, determining heterogenous toxicity syndromes (TS). We reviewed intensive first line triplet chemotherapy-based regimens in metastatic gastro-intestinal cancers (mGI), based on FIr/FOx schedule, fluorouracil and weekly alternating irinotecan/oxaliplatin, to point out limiting TS (LTS) relevance.

Methods: Metastatic colo-rectal (mCRC), pancreatic ductal adenocarcinoma (mPDAC), gastric carcinoma (mGC) patients were enrolled by careful decision-making including age, performance status (PS), and comorbidity status in real life phase II studies: FIr-B/FOx adding bevacizumab (B) overall, FIr-C/FOx-C adding cetuximab (C) in KRAS/NRAS wild-type mCRC; FIr/FOx in mPDAC; FD/FOx adding docetaxel (D) in mGC. Toxicity, individual LTS, LT alone (LTS-single site, LTS-ss) or associated to other limiting/G2 toxicities (LTS-multiple sites, LTS-ms) were evaluated, compared by chi-square test. In FIr-C/FOx-C, 5-fluorouracil/irinotecan pharmacogenomic biomarkers, 5-fluorouracil degradation rate (5-FUDR), SNPs ABCB1, CYP3A4, DYPD, UGT1A1 were evaluated, related with LTS.

Results: FIr-B/FOx, FIr-C/FOx-C in mCRC, FIr/FOx in mPDAC, FD/FOx in mGC, showed activity, efficacy, toxicities similar to reported triplet regimens. LTS: mCRC FIr-B/FOx 44%, LTS-ms 24%, LTS-ss 20%, in young-elderly 46%, LTS-ms significantly increased vs. LTS-ss; FIr-C/FOx-C 65.5%, significantly increased LTS-ms vs. LTS-ss, in young-elderly 83%; mPDAC FIr/FOx 27.5%, mostly LTS-ms, in young-elderly 38.4% all LTS-ms; mGC FD/FOx 30%, all LTS-ms, in young-elderly 25%. Reduced FUDR, SNPs CYP3A4, UGT1A1, >1 positive pharmacogenomic biomarkers were prevalent in patients with gastrointestinal LTS.

Conclusions: LTS is an innovative clinical parameter of toxicity burden, differential treatment-related TS in individual patient. LTS can evaluate pharmacogenomic biomarkers predictive relevance to select mGI patients fit for intensive treatments, at risk of limiting gastrointestinal toxicity.

Trial Registrations: The trials were registered at Osservatorio Nazionale sulla Sperimentazione Clinica dei Medicinali (OsSC) Agenzia Italiana del Farmaco (AIFA) Numero EudraCT 2007-004946-34, and Osservatorio Nazionale sulla Sperimentazione Clinica dei Medicinali (OsSC) Agenzia Italiana del Farmaco (AIFA) Numero EudraCT 2009- 016793-32.

FOLFOXIRI Plus Panitumumab As First-Line Treatment of RAS Wild-Type Metastatic Colorectal Cancer: The Randomized, Open-Label, Phase II VOLFI Study (AIO KRK0109)

PURPOSE

This trial investigated the addition of panitumumab to triplet chemotherapy with fluorouracil/folinic acid, oxaliplatin, and irinotecan (FOLFOXIRI) in a two-to-one randomized, controlled, open-label, phase II trial in patients with untreated RAS wild-type (WT) metastatic colorectal cancer.

PATIENTS AND METHODS

The primary end point was objective response rate (ORR) according to RECIST (version 1.1). The experimental arm (modified FOLFOXIRI [mFOLFOXIRI] plus panitumumab) was considered active if the ORR was ≥ 75%. The experimental ORR was compared with an estimated ORR of 60% based on historical data, verified by a randomized control group (FOLFOXIRI). The power of the trial was 80%, with a potential type I error of 0.05. Secondary end points included secondary resection rate, toxicity, progression-free survival, and overall survival.

RESULTS

A total of 63 patients were randomly assigned to the experimental arm and 33 patients to the control arm. The ORR of the mFOLFOXIRI plus panitumumab arm exceeded 75% and was higher when compared with that of FOLFOXIRI (87.3% v 60.6%; odds ratio, 4.469; 95% CI, 1.61 to 12.38; P = .004). The secondary resection rate was improved with the addition of panitumumab (33.3% v 12.1%; P = .02). Progression-free survival was similar in the study arms, whereas overall survival showed a trend in favor of the panitumumab-containing arm (hazard ratio for death, 0.67; 95% CI, 0.41 to 1.11; P = .12).

CONCLUSION

The addition of panitumumab to mFOLFOXIRI in patients with RAS WT metastatic colorectal cancer improved the ORR and rate of secondary resection of metastases and represents a treatment option in selected and fit patients in need of highly active first-line therapy. Future studies should determine whether the addition of panitumumab to mFOLFOXIRI prolongs survival.

Distinguishing Features of Cetuximab and Panitumumab in Colorectal Cancer and Other Solid Tumors

Cetuximab and panitumumab are two distinct monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR), and both are widely used in combination with chemotherapy or as monotherapy to treat patients with RAS wild-type metastatic colorectal cancer. Although often considered interchangeable, the two antibodies have different molecular structures and can behave differently in clinically relevant ways. More specifically, as an immunoglobulin (Ig) G1 isotype mAb, cetuximab can elicit immune functions such as antibody-dependent cell-mediated cytotoxicity involving natural killer cells, T-cell recruitment to the tumor, and T-cell priming via dendritic cell maturation. Panitumumab, an IgG2 isotype mAb, does not possess these immune functions. Furthermore, the two antibodies have different binding sites on the EGFR, as evidenced by mutations on the extracellular domain that can confer resistance to one of the two therapeutics or to both. We consider a comparison of the properties of these two antibodies to represent a gap in the literature. We therefore compiled a detailed, evidence-based educational review of the known molecular, clinical, and functional differences between the two antibodies and concluded that they are distinct therapeutic agents that should be considered individually during treatment planning. Available data for one agent can only partly be extrapolated to the other. Looking to the future, the known immune activity of cetuximab may provide a rationale for this antibody as a combination partner with investigational chemotherapy plus immunotherapy regimens for colorectal cancer.

Activity and Safety of Cetuximab Plus Modified FOLFOXIRI Followed by Maintenance With Cetuximab or Bevacizumab for RAS and BRAF Wild-type Metastatic Colorectal Cancer: A Randomized Phase 2 Clinical Trial

Importance

The combination of a triple-drug chemotherapy regimen with an anti-epidermal growth factor receptor (EGFR) agent as a first-line treatment of metastatic colorectal cancer (mCRC) showed promising activity along with safety concerns in single-arm phase 2 trials. The role of maintenance following chemotherapy and anti-EGFR and the optimal regimen to be adopted are not established.

Objectives

To evaluate the activity and safety of cetuximab plus modified FOLFOXIRI (mFOLFOXIRI) and explore the role of maintenance with cetuximab or bevacizumab in RAS and BRAF wild-type mCRC.

Design, Setting, and Participants

In a prospective, noncomparative, open-label, multicenter, randomized phase 2 trial, patients aged 18 to 75 years with unresectable, previously untreated RAS and BRAF wild-type (before amendment, KRAS wild-type) mCRC were recruited from 21 oncology units in Italy from October 19, 2011, to March 1, 2015 (followed up through May 31, 2017). In total, 323 patients were screened and 143 were randomized to 2 treatment arms to receive as a first-line induction a regimen of mFOLFOXIRI plus cetuximab followed by cetuximab (arm A) or bevacizumab (arm B) until disease progression. Primary analyses were conducted in a modified intention-to-treat population.

Interventions

mFOLFOXIRI plus cetuximab repeated every 2 weeks for up to 8 cycles, followed by maintenance with cetuximab or bevacizumab until disease progression.

Main Outcomes and Measures

The primary end point was the 10-month progression-free rate (PFR); secondary end points included progression-free and overall survival, response rate, rate of metastases resection, and adverse events.

Results

Of 143 patients randomized, 116 (81.1%) (median [interquartile range (IQR)] age, 59.5 [53-67] years; 34 [29.3%] women) had RAS and BRAF wild-type mCRC. At a median (IQR) follow-up of 44.0 (30.5-52.1) months, 10-month PFRs were 50.8% (90% CI, 39.5%-62.2%) in arm A and 40.4% (90% CI, 29.4%-52.1%) in arm B. The overall response rate was 71.6% (95% CI, 62.4%-79.5%). Main grade 3/4 adverse events were neutropenia (occurring in 36 patients [31%]), diarrhea (in 21 patients [18%]), skin toxic effects (in 18 patients [16%]), asthenia (in 11 patients [9%]), stomatitis (in 7 patients [6%]), and febrile neutropenia (in 3 patients [3%]).

Conclusions and Relevance

Although neither of the 2 arms met the primary end point, the findings indicate that a 4-month induction regimen of mFOLFOXIRI plus cetuximab is feasible and provides relevant activity results, leading to a high surgical resection rate.

Trial Registration

clinicaltrials.gov Identifier: NCT02295930.

Emergence of RAS mutations in patients with metastatic colorectal cancer receiving cetuximab-based treatment: a study protocol

Background

In the management of patients with RAS wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) therapies have demonstrated a clinical benefit, with longer survival. However, the correlation between the emergence of circulating RAS mutations and secondary resistance to anti-EGFR therapies requires further elucidation. In this study, we aim to examine evolutionary changes in RAS mutations through liquid biopsy in patients with mCRC during and after anti-EGFR therapy.

Methods

A total of 120 patients diagnosed with RAS wild-type mCRC will be enrolled in this study. Patients will receive a cetuximab-based infusional 5-fluorouracil regimen as first-line treatment. Cetuximab-based treatment is expected to continue until disease progression, intolerable toxic effects, or withdrawal of consent. Blood samples from enrolled patients will be collected before and then every 3 months during cetuximab-based treatment and also at disease progression. These blood samples will be evaluated for RAS resistance mutations by using the MassARRAY platform. The primary endpoint is the percentage of RAS mutations detected in circulating DNA from patients during cetuximab treatment. The correlation between the tumor response and survival outcomes of these patients and the emergence of circulating RAS mutations will be further analyzed.

Discussion

Liquid biopsy is a powerful technology that can represent tumor heterogeneity in a relatively noninvasive manner. Because RAS mutations play a major role in resistance to anti-EGFR therapy for mCRC, examining evolutionary changes in these mutations during such treatment through liquid biopsy would be useful. After comprehensively analyzing the emergence of circulating RAS mutations and its clinical relevance in this study, our results should provide practical guidance on anti-EGFR therapy for mCRC.

Trial registration

The date of trial registration (NCT03401957) in this study was January 17, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5826-7) contains supplementary material, which is available to authorized users.

The impact of panitumumab treatment on survival and quality of life in patients with RAS wild-type metastatic colorectal cancer

Panitumumab is a fully human monoclonal antibody targeting the epidermal growth factor receptor (EGFR). It is currently approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC) in combination with chemotherapy in first- and second-line and as monotherapy in chemorefractory patients. This review will provide an overview of main efficacy data on panitumumab from its early development up to latest evidences, including novel perspectives on predictive biomarkers of anti-EGFRs efficacy and mechanisms of secondary resistance. Quality of life (QoL) related issues and panitumumab safety profile will be addressed as well.

Intensive first-line FIr-C/FOx-C association of triplet chemotherapy plus cetuximab in RAS wild-type metastatic colorectal cancer patients: preliminary phase II data and prediction of individual limiting toxicity syndromes by pharmacogenomic biomarkers

Background:

Intensive triplet chemotherapy/bevacizumab significantly increased metastatic colorectal cancer (MCRC) outcome. This phase II study investigated the safety/activity of FIr-C/FOx-C triplet/cetuximab (CET) in first-line RAS wild-type and the prediction of individual limiting toxicity syndromes (LTS) by pharmacogenomic biomarkers.

Methods:

A Simon two-step design was used: p0 70%, p1 85%, power 80%, α5%, β20%; projected objective response rate (ORR) I step 14/19. FIr-C/FOx-C: 5-fluorouracil (5-FU) 12h-timed flat infusion 900 mg/m² d1–2, 8–9, 15–16, 22–23; irinotecan (CPT-11) 160 mg/m² d1 and 15, oxaliplatin 80 mg/m² d8 and 22; CET 400mg/m² then 250 mg/m² d1, 8, 15, 22; every 28 days. Toxicity, and individual LTS were evaluated, compared by a Chi-square test; and activity/efficacy by log-rank. 5-FU/CPT-11 pharmacogenomic biomarkers, 5-FU degradation rate (5-FUDR), single nucleotide polymorphisms (SNPs) ABCB1, CYP3A4, DYPD, UGT1A1 were evaluated in patients with LTS and at a recommended dose.

Results:

A total of 29 patients <75 years, with a primary/intermediate Cumulative Index Rating Scale were enrolled; the median age was 59 years; there were 7 young-elderly (yE; 24%). Recommended CPT-11/5-FU doses were 120/750 mg/m². In the intent-to-treat analysis, the ORR was 58.6%. The primary endpoint was met in patients who received the planned three treatment cycles: the objective response (OR) was 14/18 (78%). At a median follow up of 18 months, progression-free survival (PFS) was 12, and overall survival (OS) was 23 months. At the recommended doses (received dose intensity >80%), grade 3–4 toxicities were: diarrhea 23%, asthenia 15%, vomiting 8%, hypertransaminasemy 8%; LTS 19 (65.5%), with 83% in yE patients. LTS prevalently multiple (ms) versus single site were 59% versus 7% (p = 0.006). The prevalence of reduced FUDR was 56%, SNPs CYP3A4 22%, UGT1A1 71%, and of >2 positive pharmacogenomics biomarkers was 78%, prevalently reported in patients who developed gastrointestinal LTS.

Conclusions:

FIr-C/FOx-C is highly active and tolerable at recommended doses in non-elderly RAS wild-type MCRC patients. LTS provided an evaluation of the toxicity burden in individual patients. Reduced FUDR, CYP3A4, and UGT1A1 SNPs may predict individual LTS-ms in patients at risk of limiting gastrointestinal toxicity.

Trial registration:

The trial was registered at Osservatorio Nazionale sulla Sperimentazione Clinica dei Medicinali (OsSC) Agenzia Italiana del Farmaco (AIFA) Numero EudraCT 2009-016793-32.

Triple-drug chemotherapy regimens in combination with an anti-EGFR agent in metastatic colorectal cancer - prospects from phase II clinical trials

INTRODUCTION

The addition of monoclonal antibody (mAb) epidermal growth factor receptor (EGFR) inhibitors to classic chemotherapy doublet backbones has improved survival of metastatic colorectal cancer (mCRC). However, the role of triple-drug chemotherapy regimens in combination with an anti-EGFR mAb inhibitor is not yet clear.

AREAS COVERED

The activity of triple-drug chemotherapy regimens when combined with an anti-EGFR mAb in mCRC patients is examined. We describe the overall safety and tolerability profiles based on a literature review of all published phase I and II clinical trials in this setting. Drug exposure, tumor mutational status, and metastases resectability are discussed. A review of PubMed and abstracts of major oncology congresses from 2009 to 2018, with MeSH and full-text search terms for clinical trials of anti-EGFR for 'metastatic' or 'advanced' 'colorectal cancer/adenocarcinoma' was implemented. Only English language publications were included.

EXPERT OPINION

Efficacy data from phase II trials are promising, but the safety profiles are not as encouraging; the development of severe diarrhea and acneiform rash limit the drug exposure that is critical for improved outcomes. Phase II studies of these triplet chemotherapy/anti-EGFR mAb combinations have focused on conversion therapy in liver-limited disease or in the first-line setting in advanced disease. The identification of biomarkers of response and toxicity may support the use of personalized medicine and more precise design of phase III trials.

Intrahepatic Oxaliplatin and Systemic 5-FU +/- Cetuximab in Chemo-Naïve Patients with Liver Metastases from Colorectal Cancer

BACKGROUND

In case of response to chemotherapy, unresectable liver metastases from colorectal cancer can be converted to resectable and thereby obtain a chance of cure. The primary aim of this trial was to evaluate the response rate with intrahepatic oxaliplatin in combination with systemic 5-FU +/- cetuximab. Secondary aims were to evaluate the conversion rate from unresectable to resectable liver metastases, median progression-free survival, median overall survival, and toxicity.

METHODS

Forty-five chemo-naïve patients with liver metastases from colorectal cancer were treated in a prospective phase II trial. Calcium folinate and 5-FU were delivered systemically while oxaliplatin was delivered alternating between systemic and intrahepatic administration. When oxaliplatin was delivered intrahepatic-ally, infusion time was reduced to 10 min followed by embolic material. In patients with KRAS wild-type tumors, cetuximab was added.

RESULTS

The treatment was well tolerated and only pain in the liver and a mild increase in liver enzymes were observed after intrahepatic oxaliplatin. The patients obtained a response rate of 82%. Further, 58% converted from having unresectable to resectable liver metastases. The median overall survival and progression-free survival were 38.7 months (95% confidence interval [CI] 33.0-44.3) and 12.9 months (95% CI 10.2-15.6), respectively.

CONCLUSIONS

Intrahepatic infusion of oxaliplatin in 10 min with systemic 5-FU to patients with chemo-naïve colorectal cancer is feasible and with low toxicity. A high response rate and long median overall survival were obtained.

FOLFOXIRI plus biologics in advanced colorectal cancer

INTRODUCTION

The combination of oxaliplatin, irinotecan, fluorouracil (5-FU), and leucovorin (FOLFOXIRI) results in improved outcomes compared with standard chemotherapy when used in frontline to treat patients with metastatic colorectal cancer (mCRC). FOLFOXIRI has been recently combined with biologic agents aiming further improvement in outcomes.

AREAS COVERED

This manuscript provides a comprehensive review of the results achieved by the FOLFOXIRI+biologic combination when used as first-line treatment in patients with mCRC. The search retrieved 19 clinical trial reports and 7 ongoing trials. The results are discussed focusing on secondary resection of metastatic disease, impact of sidedness (right-left primary tumor site), and impact of biomarkers.

EXPERT OPINION

Panitumumab is the only biologic that has proved its value when added to FOLFOXIRI in a randomized clinical trial. FOLFOXIRI-bevacizumab has the widest data from two large randomized phase III trials, being an option to be used in both the palliative and the conversion-therapy settings. However, the true benefit from adding bevacizumab remains to be established as it has not been evaluated in a randomized setting yet. Data on response rates and secondary resection rates are promising with the FOLFOXIRI-anti-EGFR combinations and may constitute a valuable option. Results of ongoing head-to-head studies will shed additional light on this issue.

Weekly alternate intensive regimen FIrB/FOx in metastatic colorectal cancer patients: an update from clinical practice

Background

Several trials evaluated the role of intensive regimens, made of triplet chemotherapies plus bevacizumab, as first-line treatment for patients with metastatic colorectal cancer (mCRC). We previously reported, in a Phase II prospective study, the efficacy and the tolerability of FIrB/FOx regimen, reporting interesting results in terms of received dose intensities (rDIs) and safety.

Methods

We reported a retrospective update of 85 patients treated with FIrB/FOx, an intensive regimen of 5-fluorouracil, bevacizumab, and weekly alternate irinotecan and oxaliplatin, to confirm its feasibility in “real life”. Subgroup analyses were performed, particularly among patients treated with standard and modified FIrB/FOx (based on age, performance status, and/or comorbidities).

Results

Overall, 3-month objective response rate (ORR) and 6-month ORR were 75.9% and 55.3%, respectively. Median progression-free survival (PFS) and median overall survival (OS) were 14.4 and 34.9 months, respectively. Among the patients treated with standard and modified regimens, 3-month ORR, PFS, and OS were 75.8% and 76% (P=1.0000), 14.4 and 14.4 months (P=0.8589), and 37.8 and 26.6 months (P=0.7746), respectively. Among the K/NRAS wild-type and K/NRAS mutant patients, 3-month ORR, PFS, and OS were 95.2% and 74.5% (P=0.0526), 15.3 and 14.4 months (P=0.8753), and 37.8 and 51.4 months (P=0.8527), respectively. The rDIs were ≥80% of full doses both in the standard and in the modified regimens subgroups. Cumulative G3/4 toxicities were neutropenia (14.1%), diarrhea (17.6%), asthenia (9.4%), vomiting (5.6%), and hypertension (16.5%).

Conclusion

This update shows that intensive regimens such as FIrB/FOx are also feasible options for first-line treatment of mCRC patients in the “real-life” setting.

Safety and effectiveness of FOLFOXIRI plus molecular target drug therapy for metastatic colorectal cancer: A multicenter retrospective study

Introduction

FOLFOXIRI plus bevacizumab has a promising efficacy as first-line systemic chemotherapy for metastatic colorectal cancer (mCRC). This study aimed to evaluate the safety and effectiveness of FOLFOXIRI plus antibodies.

Results

Fifty-five patients were enrolled (median age: 60 years, males: 25, females: 30). Twenty-six subjects had RAS mutations and 29 had RAS wild-type. Anti-VEGF and anti-EGFR antibodies were administered to 38 and 17 patients, respectively. The most common severe adverse event was neutropenia (51%). The overall response rate (ORR) was 69% (55% with anti-VEGF antibodies and 100% with anti-EGFR antibodies; P = 0.190), and the disease control rate was 98% (stable disease: 16 patients). With a median follow-up period of 18.4 months, the median progression-free survival (mPFS) was 11.0 months and the median overall survival (mOS) was 41.9 months. The mPFS and mOS did not significantly differ between patients treated with anti-EGFR antibodies and those with anti-VEGF antibodies.

Methods

We retrospectively collected data from mCRC patients treated with FOLFOXIRI plus antibodies between March 2014 and December 2017.

Conclusions

FOLFOXIRI plus antibody therapy was effective in patients with mCRC. The response rate was higher in patients treated with anti-EGFR antibodies than in those treated with anti-VEGF antibodies.

The changing face of treatment for metastatic colorectal cancer

Introduction: Since late 1990's therapy of metastatic colorectal cancer (mCRC) patients has changed considerable, and the combination of doublet or triplet chemotherapy and a targeted agent are now routinely used. With the introduction of more intensified regimens, it has become even more important to identify patients that will benefit from and can tolerate therapy. Furthermore, the increasing understanding of the biology of mCRC has led to the discovery of new potential targets. Therefore, therapy of patients with mCRC has undergone considerable change from 'one strategy fits all' towards a more personalized therapy. Areas covered: We present an overview of the recent literature on approved systemic treatment of mCRC however with focus on how the treatment strategy has changed based on clinical and molecular parameters that presently are used routinely in the clinical situation. Expert commentary: The face of treatment of mCRC has changed from 'one strategy fits all' to a personalized approach in which both clinical, molecular parameters and the aim of therapy have to be taking into account when planning the optimal treatment strategy for the individual mCRC patient.

Induction chemotherapy followed by neoadjuvant chemoradiotherapy and surgery in locally advanced rectal cancer: preliminary results of a phase II study

Background and purpose

To report preliminary results of induction chemotherapy (IC) followed by neoadjuvant chemoradiotherapy (CRT) and surgery in locally advanced rectal cancer (LARC) patients.

Materials and methods

This is the preliminary evaluation of a phase II study. Patients with histologically proven rectal adenocarcinoma, stage II-III disease, who met the inclusion criteria, received induction FOLFOXIRI (5-FU, leucovorin, oxaliplatin and irinotecan) regimen in combination with targeted agents followed by CRT and surgery. Analysis of the first 8 patients was required to confirm the treatment feasibility before the accrual of 20 additional patients.

Results

The first 8 patients were evaluated. The median follow-up time was 23 months. There were no treatment-related deaths. Trimodality strategy was well tolerated with high compliance and a good level of toxicity. There were no evidence of febrile neutropenia and any grade 4 adverse events were recorded. Three patients had pathologic complete response (pCR) and 1 patient had a nearly pCR (ypT1 ypN0).

Conclusion

Preliminary results are encouraging. FOLFOXIRI regimen plus targeted agents followed by CRT and surgery seems a safe approach. Longer follow-up and higher number of patients are mandatory to confirm such findings.

Duration of first-line treatment for metastatic colorectal cancer: Translating the available evidence into general recommendations for routine practice

Over the last two decades the number of front-line regimens for metastatic colorectal cancer has progressively increased. Nevertheless, there is still no consensus on the optimal duration of treatment or the role of de-escalated/maintenance strategies after induction chemotherapy. In this article we provide an overview of the studies that addressed the duration of first-line systemic treatment with cytotoxic agents plus or minus targeted therapies highlighting caveats and limitations of the same. Also, we try to translate the available evidence into practical recommendations that can be used in everyday practice to inform treatment decisions. The main conclusion of our review article is that continuing induction treatment until progression may improve disease control but there is no evidence to suggest that adopting this practice can prolong survival. On the other hand, de-escalated treatment strategies offer an opportunity to reduce the burden of toxicity while maintaining satisfactory oncological outcomes.

TRIPLETE: a randomised phase III study of modified FOLFOXIRI plus panitumumab versus mFOLFOX6 plus panitumumab as initial therapy for patients with unresectable RAS and BRAF wild-type metastatic colorectal cancer

Background

FOLFOXIRI plus bevacizumab is considered a standard option in the upfront treatment of clinically selected patients with metastatic colorectal cancer irrespective of RAS and BRAF molecular status. The randomised MACBETH and VOLFI studies showed that a modified FOLFOXIRI regimen in combination with cetuximab or panitumumab, respectively, achieved high therapeutic activity in RAS and BRAF wild-type patients with an acceptable toxicity profile. Drawing from these considerations, we designed TRIPLETE study aiming at comparing two different chemotherapy backbones (mFOLFOXIRI or mFOLFOX6) in combination with panitumumab in the first-line treatment of patients with RAS and BRAF wild-type metastatic colorectal cancer.

Methods

This is a prospective, open-label, multicentre phase III trial in which initially unresectable and previously untreated RAS and BRAF wild-type metastatic colorectal cancer patients are randomised to receive a standard treatment with mFOLFOX6 plus panitumumab or an experimental regimen with modified FOLFOXIRI (irinotecan 150 mg/m², oxaliplatin 85 mg/m², L-leucovorin 200 mg/m², 5-fluoruracil 2400 mg/m² 48-hour continuous infusion) plus panitumumab up to 12 cycles, followed by panitumumab plus 5-fluorouracil and L-leucovorin until disease progression. The primary endpoint is overall response rate according to RECIST 1.1 criteria.

Discussion

The relative benefit of chemotherapy intensification when using an anti-EGFR-based regimen in molecularly selected patients is unknown; TRIPLETE study aims at filling this gap of knowledge. The study is sponsored by the Gruppo Oncologico Nord Ovest Cooperative Group and is currently ongoing at 42 Italian centres.

Clinical trial information

NCT03231722.

First-line molecular therapies in the treatment of metastatic colorectal cancer - a literature-based review of phases II and III trials

Introduction:

Metastatic colorectal cancer (mCRC) is one of the most common cancers and the second leading cause of cancer worldwide. With the improvement of systemic and operative therapies, median overall survival (mOS) reached 30 months or longer. Here, we will review the use of the anti-vascular endothelial growth factor (VEGF) and anti-epidermal growth factor receptor (EGFR) antibodies in combination with doublet and triplet chemotherapy in patients with borderline and primary unresectable mCRC.

Methods:

Phases II and III trials were included in investigating chemotherapy in the first-line in combination with an anti-VEGF(R) or anti-EGFR in a cohort of patients with mCRC.

Results:

The VEGF-antibody bevacizumab has improved progression-free survival (PFS) in several phase III trials in combination with a chemotherapy doublet. More recently, a higher efficacy has been demonstrated in combination with an intensified chemotherapy including 5-fluoropyrimidine (5-FU), oxaliplatin, and irinotecan within the phase III TRIBE study. Similarly, high resectability rates have been shown in the phase II Olivia trial for patients with liver-limited disease with an intensified chemotherapeutic regime. However, this increase in efficacy was accompanied by an increase in toxicity as well. The efficacy of the EGFR-antibodies cetuximab and panitumumab has been shown in several phase III trials, but their use is restricted to patients whose tumors are RAS wildtype (WT). The phase II trials, CELIM and PLANET, demonstrated a favorable long-term survival for patients with initially non-resectable colorectal liver metastases who respond to conversion therapy with EGFR-antibodies and undergo secondary resection. The CLGB and FIRE-3 trials delivered an inconsistent finding whether anti-VEGF or -EGFR treatment is the better option in the first-line setting. However, there is increasing evidence from post hoc analyses of prospective clinical trials that patients with left-sided tumors benefit from EGFR-directed combination therapy in terms of prolongation of OS and PFS compared with limited, if any, benefit for those with right-sided tumors.

Conclusion:

Both anti-VEGF- and anti-EGFR-directed therapies represent efficient treatment options for patients with mCRC in the first line. For patients with RAS WT, left-sided tumor anti-EGFR-based treatment is recommended. Intensified regimens can be offered initially to unresectable patients in order to achieve resectability at a price of higher toxicity.

Phase I study of primary treatment with 5-FU, oxaliplatin, irinotecan, levofolinate, and panitumumab combination chemotherapy in patients with advanced/recurrent colorectal cancer involving the wild-type RAS gene: the JACCRO CC-14 study

Background

FOLFOXIRI is now regarded as the chemotherapy regimen that offers the best platform for the treatment of colorectal cancer. However, the safety and efficacy of FOLFOXIRI + panitumumab has not been demonstrated. We conducted a phase I study to determine the recommended dose of FOLFOXIRI + panitumumab as first-line treatment for RAS wild-type metastatic colorectal cancer (mCRC).

Methods

Patients received combination therapy consisting of panitumumab (6 mg/kg on day 1) + FOLFOXIRI [irinotecan (CPT-11), oxaliplatin (L-OHP) 85 mg/m², and folinate (LV) 200 mg/m²] on day 1, followed by fluorouracil (5-FU) 3200 mg/m² infused as a 46-h continuous infusion starting on day 1) repeated every 2 weeks as first-line treatment of RAS wild-type mCRC patients. A decrease in CPT-11 dose was planned (started at level 1: CPT-11 165 mg/m²).

Results

Seven patients were enrolled, and six were assessed for safety and efficacy. Maximum tolerated dose was not reached at level 1; all patients were treated at these levels. The common Grade 3 or 4 relevant toxicities were diarrhea (50%), hypokalemia (33%) and stomatitis (33%). No treatment-related deaths occurred. Of the six patients assessed four had partial response and the two others had stable disease; hence, the response rate was 66.7% (95% confidence interval 28.9–100%) and the disease control rate was 100%. Time to protocol treatment failure was 7.2 (1.4–7.3) months.

Conclusion

The FOLFOXIRI + panitumumab chemotherapy regimen was well tolerated by our patients with mCRC and showed promising anti-tumor activity. The recommended phase II dose was determined to be the same as the standard doses of this regimen used worldwide.

Systemic Therapy for Metastatic Colorectal Cancer: From Current Standards to Future Molecular Targeted Approaches

Over the past 20 years, substantial advances have been made in the treatment of patients with metastatic colorectal cancer (mCRC). In particular, there is now a wide range of options for the front-line treatment of mCRC. Sophisticated molecular technologies have been developed to identify novel prognostic and predictive biomarkers for CRC. DNA sequencing technology has made remarkable advances in recent years, primarily as a result of the development of next-generation sequencing and whole exome sequencing, which are powerful new tools for the discovery of predictive molecular biomarkers to facilitate the delivery of personalized medicine. In addition to tumor tissue, recent efforts have focused on analyzing circulating tumor DNA in peripheral blood. Herein, we review the evolution of standard chemotherapy and targeted therapy strategies for the treatment of mCRC in the front-line setting, the molecular technologies that are presently being used to facilitate our ability to practice individualized medicine, and the practical aspects of applying molecular biomarkers to everyday clinical practice.

A Review of Clinical Studies and Practical Guide for the Administration of Triplet Chemotherapy Regimens with Bevacizumab in First-line Metastatic Colorectal Cancer

Colorectal cancer is the third most common cancer worldwide. A significant proportion of patients presents with unresectable metastatic disease or develops metachronous metastases following surgical resection of the primary tumor. The prognosis of the disease has improved over the past two decades, with extended multimodality treatment options and the development of increasingly intensified chemotherapy regimens that now typically include targeted biologics. A recent advance in therapy is a treatment regimen composed of three chemotherapeutic agents (i.e., triplet chemotherapy: 5-fluorouracil [5-FU]/leucovorin [LV], oxaliplatin, and irinotecan; FOLFOXIRI) in combination with the vascular endothelial growth factor inhibitor bevacizumab. This regimen has been shown to elicit significantly improved objective response rates and median progression-free survival compared with 5-FU/LV and irinotecan in combination with bevacizumab. However, triplet chemotherapy has been associated with increased rates of chemotherapy-related adverse events, and treatment-emergent adverse events should be properly managed to minimize treatment interruption or discontinuation. We present herein a review of clinical studies evaluating the safety and efficacy of FOLFOXIRI with bevacizumab in metastatic colorectal cancer, and propose a practical guide for the management of adverse events associated with the regimen.

A triplet combination with capecitabine/oxaliplatin/irinotecan (XELOXIRI) plus cetuximab as first-line therapy for patients with metastatic colorectal cancer: a dose escalation study

PURPOSE

The addition of cetuximab to triplet chemotherapy can increase treatment efficacy for patients with metastatic colorectal cancer (mCRC). We explored the dose-limiting toxicity and feasibility of a triweekly capecitabine, oxaliplatin, irinotecan, plus cetuximab (XELOXIRI plus cetuximab) regimen in patients with wild-type KRAS mCRC.

METHODS

Patients received oxaliplatin (100 mg/m², day 1), capecitabine (1700 mg/m² per day from day 2 to 15), irinotecan (100, 120, and 150 mg/m² for dose levels 1, 2, 3, respectively, on day 1), and cetuximab (400 mg/m², day 1 and, thereafter, 250 mg/m² every week), repeated every 3 weeks. Dose-limiting toxicities (DLTs) were assessed in the first 2 treatment cycles to determine the maximum tolerated dose (MTD) and the recommended dose (RD).

RESULTS

Twelve patients received a median of 7 cycles of therapy (range 2-10). The DLT was grade 4 neutropenia, observed in 1 of 6 patients at dose level 2. The MTD was not reached at dose level 3. Therefore, the RD of irinotecan was defined as 150 mg/m². Most common grade ≥ 3 toxicities were neutropenia (50%), diarrhea (17%), and febrile neutropenia (8%). The response rate was 83% (complete and partial response: 1 and 9 patient(s), respectively), including 4 conversion cases.

CONCLUSIONS

The combination of XELOXIRI and cetuximab is feasible and has an acceptable toxicity profile; neutropenia was the DLT. The RD of irinotecan is 150 mg/m². The observed response rate was promising and warrants further investigation.

Pancreatic Cancer Arising From the Remnant Pancreas: Is It a Local Recurrence or New Primary Lesion?

Local recurrence of pancreatic cancer (PC) can occur in the pancreatic remnant. In addition, new primary PC can develop in the remnant. There are limited data available regarding this so-called remnant PC. The aim of this review was to describe the characteristics and therapeutic strategy regarding remnant PC. A literature search was performed using Medline published in English according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The incidence of remnant PC has been reported to be 3% to 5%. It is difficult to distinguish local recurrence from new primary PC. Genetic diagnosis such as Kirsten rat sarcoma viral oncogene homolog mutation may resolve this problem. For patients with remnant PC, repeated pancreatectomy can be performed. Residual total pancreatectomy is the most common procedure. Recent studies have described the safety of the operation because of recent surgical progress and perioperative care. The patients with remnant PC without distant metastasis have shown good long-term outcomes, especially those who underwent repeated pancreatectomy. Adjuvant chemotherapy may contribute to longer survival. In conclusion, this review found that both local recurrence and new primary PC can develop in the pancreatic remnant. Repeated pancreatectomy for the remnant PC is a feasible procedure and can prolong patient survival.

Triplet (FOLFOXIRI) versus doublet (FOLFOX or FOLFIRI) backbone chemotherapy as first-line treatment of metastatic colorectal cancer: A systematic review and meta-analysis

Uncertainty exists regarding the comparative effectiveness of triplet chemotherapy (FOLFOXIRI) as backbone first-line chemotherapy for metastatic colorectal cancer (mCRC). We conducted a systematic review and meta-analysis of randomized-controlled trials (RCTs) comparing triplet versus doublet chemotherapy (FOLFOX or FOLFIRI) as first-line therapy in mCRC. Methods and reporting followed PRISMA and SAMPL guidelines. Eight RCTs were included, comprising 1732 patients. In pooled analysis, FOLFOXIRI was associated with improvements in efficacy outcomes, notably with a 25% survival increase (95%CI: 10-37%). FOLFOXIRI was also associated with increased toxicity, with a non-significant 25% increase in the risk of patients experiencing grade ≥3 adverse events (95% CI: -3 to 61%) and with a 1.83 (95% CI: 1.62-2.07) increase in the rate ratio of grade ≥3 adverse events. Moderate quality evidence suggests that first-line FOLFOXIRI provides clinically meaningful efficacy benefits in this setting, at the expense of increased toxicity. Further research is warranted to better characterize safety and to evaluate the most beneficial combination with targeted agents.

BRAF-Mutated Colorectal Cancer: What Is the Optimal Strategy for Treatment?

OPINION STATEMENT

The BRAF activating mutation, harbored by approximately 10% of colorectal cancers (CRC), confers dramatic prognosis to advanced diseases. In early-stage setting, the identification of the BRAF mutation does not impact the therapeutic decision. Yet, the BRAF mutation could be considered as a stratification factor in adjuvant trials, because of its prognostic impact after relapse. Moreover, both BRAF mutation and mismatch repair (MMR) statuses should be determined in all CRC to help identify sporadic tumors versus Lynch syndrome-related tumors. Indeed, in patients with MMR-deficient (dMMR) tumors and MLH1 loss of expression, the BRAFV600E mutation indicates a sporadic origin. In advanced BRAF-mutated CRC, the standard of care remains fluoropyrimidine-based cytotoxic regimen in combination with bevacizumab. Although a recent meta-analysis showed that there was insufficient data to justify the exclusion of anti-EGFR monoclonal antibodies, antiangiogenic agents should be preferred in the first-line setting. Despite the lack of a randomized phase 3 study dedicated to BRAF-mutated CRC, chemotherapy intensification combining a quadruple association of 5-fluorouracil, oxaliplatin, irinotecan (FOLFOXIRI), and bevacizumab seems like a valid option. Although first results with BRAF inhibitors as single agents in BRAF-mutated CRC were disappointing, their association with therapies targeting the MAPK pathway seems to overcome the primary resistance to BRAF inhibition. In the field of sporadic CRC, the BRAF mutation is strongly associated with MMR deficiency. Considering breakthrough results of immune checkpoint inhibitors in dMMR repair tumors, determination of the MMR status appears to be mandatory. Given the dramatic prognosis conferred by the BRAF mutation, patients with BRAF-mutated advanced CRC need to be systematically identified and proposed for clinical trial enrolment in order to benefit from innovative therapies.

Final analysis of the randomised PEAK trial: overall survival and tumour responses during first-line treatment with mFOLFOX6 plus either panitumumab or bevacizumab in patients with metastatic colorectal carcinoma

PURPOSE

To report planned final overall (OS) and progression-free survival (PFS) analyses from the phase II PEAK trial (NCT00819780).

METHODS

Patients with previously untreated, KRAS exon 2 wild-type (WT) metastatic colorectal cancer (mCRC) were randomised to mFOLFOX6 plus panitumumab or bevacizumab. The primary endpoint was PFS; secondary endpoints included OS, objective response rate, duration of response (DoR), time to response, resection and safety. Treatment effect by tumour RAS status was a prespecified objective. Exploratory analyses included early tumour shrinkage (ETS) and depth of response (DpR).

RESULTS

One hundred seventy patients had RAS WT and 156 had RAS WT/BRAF WT mCRC. Median PFS was longer for panitumumab versus bevacizumab in the RAS WT (12.8 vs 10.1 months; hazard ratio (HR) = 0.68 [95% confidence intervals (CI) = 0.48-0.96]; p = 0.029) and RAS WT/BRAF WT (13.1 vs 10.1 months; HR = 0.61 [95% CI = 0.42-0.88]; p = 0.0075) populations. Median OS (68% OS events) for panitumumab versus bevacizumab was 36.9 versus 28.9 months (HR = 0.76 [95% CI = 0.53-1.11]; p = 0.15) and 41.3 versus 28.9 months (HR = 0.70 [95% CI = 0.48-1.04]; p = 0.08), in the RAS WT and RAS WT/BRAF WT populations, respectively. Median DoR (11.4 vs 9.0 months; HR = 0.59 [95% CI = 0.39-0.88]; p = 0.011) and DpR (65.0 vs 46.3%; p = 0.0018) were improved in the panitumumab group. More panitumumab patients experienced ≥30% ETS at week 8 (64 vs 45%; p = 0.052); ETS was associated with improved PFS/OS. No new safety signals occurred.

CONCLUSIONS

First-line panitumumab + mFOLFOX6 increases PFS versus bevacizumab + mFOLFOX6 in patients with RAS WT mCRC.

Anti-EGFR monoclonal antibody panitumumab for the treatment of patients with metastatic colorectal cancer: an overview of current practice and future perspectives

INTRODUCTION

Targeted agents alone or in combination with chemotherapy are current standard of treatment for metastatic colorectal cancer (mCRC). Panitumumab is a fully human monoclonal antibody which inhibits the epidermal growth factor receptor (EGFR). It is currently approved in combination with chemotherapy in first- and second-line and as a monotherapy in chemorefractory patients. RAS gene mutations confer resistance to anti-EGFR agents; thus, panitumumab is restricted to the treatment of RAS wild-type (WT) tumors. Areas covered: This review explores the available data on panitumumab and presents new perspectives on predictive markers of anti-EGFR efficacy including primary tumor sidedness and BRAF mutations. Other details covered include panitumumab's mechanism of action, pharmacokinetics, pharmacodynamics and safety aspects of the therapy as well as mechanisms of secondary resistance and future prospects of treatment in different settings. Expert opinion: Panitumumab has significantly added to the treatment armamentarium for RAS WT mCRC. The effort spent in identifying predictive biomarkers of panitumumab efficacy has been of pivotal importance to development of the molecular selection of patients with mCRC. Primary and secondary resistance, however, still represent important issues. Novel strategies to overcome those issues are currently underway with promising results which highlight the potential use of panitumumab in combination with other targeted agents in the future.

Systemic Chemotherapy as Salvage Treatment for Locally Advanced Rectal Cancer Patients Who Fail to Respond to Standard Neoadjuvant Chemoradiotherapy

BACKGROUND

The potential of chemotherapy as salvage treatment after failure of neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC) has never been explored. We conducted a single-center, retrospective analysis to address this question.

PATIENTS AND METHODS

Patients with newly diagnosed LARC who were inoperable or candidates for extensive (i.e., beyond total mesorectal excision [TME]) surgery after long-course chemoradiotherapy and who received salvage chemotherapy were included. The primary objective was to estimate the proportion of patients who became suitable for TME after chemotherapy.

RESULTS

Forty-five patients were eligible (39 candidates for extensive surgery and 6 unresectable). Previous radiotherapy was given concurrently with chemotherapy in 43 cases (median dose: 54.0 Gy). Oxaliplatin- and irinotecan-based salvage chemotherapy was administered in 40 (88.9%) and 5 (11.1%) cases, respectively. Eight patients (17.8%) became suitable for TME after chemotherapy, 10 (22.2%) ultimately underwent TME with clear margins, and 2 (4.4%) were managed with a watch and wait approach. Additionally, 13 patients had extensive surgery with curative intent. Three-year progression-free survival and 5-year overall survival in the entire population were 30.0% (95% confidence interval [CI]: 15.0-46.0) and 44.0% (95% CI: 26.0-61.0), respectively. For the curatively resected and "watch and wait" patients, these figures were 52.0% (95% CI: 27.0-73.0) and 67.0% (95% CI: 40.0-84.0), respectively.

CONCLUSION

Systemic chemotherapy may be an effective salvage strategy for LARC patients who fail to respond to chemoradiotherapy and are inoperable or candidates for beyond TME surgery. According to our study, one out of five patients may become resectable or be spared from an extensive surgery after systemic chemotherapy.

IMPLICATIONS FOR PRACTICE

High-quality evidence to inform the optimal management of rectal cancer patients who are inoperable or candidates for beyond total mesorectal excision surgery following standard chemoradiotherapy is lacking. We show for the first time that systemic chemotherapy may be beneficial and result in one out of five poor prognosis patients becoming resectable or being spared from an extensive surgical approach. Although mores studies are needed to confirm these data, administering salvage systemic chemotherapy in this setting may have the potential to minimize morbidity associated with extensive surgical procedures and improve long-term oncological outcome.

Phase II trial of capecitabine plus erlotinib versus capecitabine alone in patients with advanced colorectal cancer

Aim & methods: Capecitabine monotherapy as palliation for advanced colorectal cancer (CRC) is generally well tolerated. Adding erlotinib, an EGFR-tyrosine kinase inhibitor, might improve efficacy versus capecitabine alone. 82 patients received capecitabine alone (Arm 1) or capecitabine with erlotinib (Arm 2). Results: Median time-to-progression (TTP) in Arm 1 was 7.9 months versus 9.2 in Arm 2. In KRAS-wild type (WT) patients TTP was 8.4 and 11.7 months in Arms 1 and 2, respectively. In KRAS-mutated patients TTP was 7.4 and 1.9 months in Arms 1 and 2, respectively (p = 0.023). Arm 2 KRAS-WT patients, left-sided primaries, had an overall survival of 16.0 versus 12.1 months in right-sided primaries. Conclusion: Adding erlotinib to capecitabine increased TTP by 3.2 months in KRAS-WT patients. This study suggests that erlotinib harms patients with KRAS-mutated advanced CRC while it may provide benefit to those with KRAS-WT CRC. Further study of EGFR-tyrosine kinase inhibitors in patients with left-sided KRAS-WT CRC is warranted.

Genomic markers of panitumumab resistance including ERBB2/ HER2 in a phase II study of KRAS wild-type (wt) metastatic colorectal cancer (mCRC)

A prospective study was conducted to identify biomarkers associated with resistance to panitumumab monotherapy in patients with metastatic colorectal cancer (mCRC). Patients with previously treated, codon 12/13 KRAS wt, mCRC were prospectively administered panitumumab 6 mg/kg IV q2weeks. Of 34 panitumumab-treated patients, 11 (32%) had progressive disease at 8 weeks and were classified as non-responders.

A Nanostring nCounter-based assay identified a 5-gene expression signature (ERBB2, MLPH, IRX3, MYRF, and KLK6) associated with panitumumab resistance (P = 0.001). Immunohistochemistry and in situ hybridization determined that the HER2 (ERBB2) protein was overexpressed in 4/11 non-responding and 0/21 responding cases (P = 0.035). Two non-responding tumors had ERBB2 gene amplification only, and one demonstrated both ERBB2 amplification and mutation. A non-codon 12/13 KRAS mutation occurred in one panitumumab-resistant patient and was mutually exclusive with ERBB2/HER2 abnormalities.

This study identifies a 5-gene signature associated with non-response to single agent panitumumab, including a subgroup of non-responders with evidence of aberrant ERBB2/HER2 signaling. KRAS wt tumors resistant to EGFRi may be identified by gene signature analysis, and the HER2 pathway plays an important role in resistance to therapy.