Untreated Metastatic Colorectal Cancer Research Articles

Trifluridine/tipiracil plus capecitabine and bevacizumab as upfront treatment for metastatic colorectal cancer: Results of the phase 1 TriComB study.

3558 Background: Capecitabine (cap) plus Bevacizumab (bev) is a standard option for previously untreated unresectable metastatic colorectal cancer (mCRC) patients (pts) deemed not fit for upfront chemotherapy doublets. A synergistic effect of the sequential administration of cap and Trifluridine/Tipiracil (FTD/TPI) has been shown both in vitro and in vivomodels. Here, we present safety and preliminary activity results of the phase 1 TriComB study, an open-label, multicenter, phase 1/2 trial, evaluating FTD/TPI in combination with cap and bev in mCRC pts. Methods: Patients with previously untreated mCRC, ineligible for oxaliplatin- and/or irinotecan- based regimens, were enrolled. A 3 + 3 dose escalation design was used to identify the recommended dose (RD) of FTD/TPI (days 15-19 and 22-26) in combination with cap (1000 mg/sqm/BID days 1-14) and bev (5 mg/kg day 1,15) in 28-days cycles. Adverse events (AEs) were reported according to CTCAE version 5.0 and tumor response was assessed by RECIST version 1.1. Results: 11 pts (5 men, 6 women; median age: 77, range: 47-84 years) were enrolled. For the first three patients (FTD/TPI: 25mg/sqm BID) no dose limiting toxicities (DLTs) were observed. At 30 mg/sqm BID dose level, 3/5 DLTs were reported: 2 pts experienced a dose delay of >7 days from the scheduled timing and 1 patient was unable to receive ≥ 75% of study drugs’ doses during the first cycle. FTD/TPI was de-escalated and 3 additional patients were treated at 25 mg/sqm BID. Since 1/6 pts experienced a DLT (grade 4 colonic perforation) that was identified as the RD. Grade 3/4 AEs are listed in the Table. As of January 2024, Overall Response Rate is 72.7% (8/11 pts) and 66.7% (4/6 pts) in the overall population and at the RD, respectively. Conclusions: The sequential combination of cap and FTD/TPI with bev is feasible. The phase 2 of the study is ongoing to evaluate antitumor activity of this regimen in the same patients' population. Clinical trial information: NCT04564898 Safety summary Clinical trial information: NCT04564898 . [Table: see text]

XELOX (capecitabine plus oxaliplatin) plus bevacizumab (anti-VEGF-A antibody) with or without adoptive cell immunotherapy in the treatment of patients with previously untreated metastatic colorectal cancer: a multicenter, open-label, randomized, controlled, phase 3 trial

Fluoropyrimidine-based combination chemotherapy plus targeted therapy is the standard initial treatment for unresectable metastatic colorectal cancer (mCRC), but the prognosis remains poor. This phase 3 trial (ClinicalTrials.gov: NCT03950154) assessed the efficacy and adverse events (AEs) of the combination of PD-1 blockade-activated DC-CIK (PD1-T) cells with XELOX plus bevacizumab as a first-line therapy in patients with mCRC. A total of 202 participants were enrolled and randomly assigned in a 1:1 ratio to receive either first-line XELOX plus bevacizumab (the control group, n = 102) or the same regimen plus autologous PD1-T cell immunotherapy (the immunotherapy group, n = 100) every 21 days for up to 6 cycles, followed by maintenance treatment with capecitabine and bevacizumab. The main endpoint of the trial was progression-free survival (PFS). The median follow-up was 19.5 months. Median PFS was 14.8 months (95% CI, 11.6–18.0) for the immunotherapy group compared with 9.9 months (8.0–11.8) for the control group (hazard ratio [HR], 0.60 [95% CI, 0.40–0.88]; p = 0.009). Median overall survival (OS) was not reached for the immunotherapy group and 25.6 months (95% CI, 18.3–32.8) for the control group (HR, 0.57 [95% CI, 0.33–0.98]; p = 0.043). Grade 3 or higher AEs occurred in 20.0% of patients in the immunotherapy group and 23.5% in the control groups, with no toxicity-associated deaths reported. The addition of PD1-T cells to first-line XELOX plus bevacizumab demonstrates significant clinical improvement of PFS and OS with well tolerability in patients with previously untreated mCRC.

Efficacy and safety of encorafenib-based regimens in colorectal cancer: A systematic review of clinical trials.

e15600 Background: BRAF gene mutation is present in 10% of the world’s 3rd common cancer, i.e., colorectal cancer (CRC). Constitutive activation of the mitogen-activated protein kinase pathway (MAPKP) results from this mutation, abnormal activation of MAPKP, inhibiting apoptosis and enhancing proliferative activity. In this systematic review, we will assess the efficacy of encorafenib (a BRAF inhibitor) based regimens in CRC. Methods: We followed PRISMA guidelines to conduct this systematic review. A literature search was performed on PubMed, Embase, and Clinicaltrials.gov with mesh terms, ‘’Colorectal Neoplasms’’ and “Proto-Oncogene Proteins B-raf” from the inception of data till 01/05/2023. We screened 4572 articles and included 1 randomized clinical trial (RCT, N = 665), and 4 non-randomized trials (nRCTs, N = 175), measuring the efficacy of encorafenib (E) based regimens in BRAF V600-mutated CRC. Results: In 4 clinical trials (N = 840), 246 patients treated with a double regimen and 373 treated with a triple regimen of E. In 2 clinical trials (N = 319), triple therapy of E + C + Binimetinib showed an overall response rate (ORR) of 47.8% and 26% in the untreated metastatic CRC (mCRC) and phase III randomized trial triple regimen arm, respectively. A recent trial on triple therapy of E + C + nivolumab (N) showed an ORR of 45% with overall survival (OS) and progression-free survival (PFS) of 11.4 and 7.3 months, respectively. In 1 randomized trial (N = 665), ORR improved from 2% in the control arm to 26% and 20% in triple and double regimens, respectively, which was mainly partial response (PR) with complete response (CR) of 4-5% in both groups. The OS was 9 and 8.4 months with a hazard ratio (HR) for death vs. control of 0.52; (95% confidence interval [CI], 0.39 to 0.70; P < 0.001) and 0.60; (95% CI, 0.45 to 0.79; P < 0.001) in the triple and dual regimen, respectively. In 1 trial of dose escalation study, alpelisib (A) was added to E + C and the addition of this third drug showed minimal changes in the ORR from 18 to 19%, and PFS improved from 3.7 to 4.2 months. (Table 1). Conclusions: A combination of BRAF inhibitors with anti-EGFR monoclonal antibodies showed a clinically significant increase in antitumor activity in BRAF-mutated mCRC compared to standard therapy. The addition of MEK/PI3K inhibitor as a third drug to E + C also showed some improvement in ORR and PFS. Triple therapy with E + C + N was also effective and tolerated well by the microsatellite stable (MSS) BRAF mutated mCRC population. Randomized trials are needed. [Table: see text]

Association of Circulating Tumor Cells and Tumor Molecular Profile With Clinical Outcomes in Patients With Previously Untreated Metastatic Colorectal Cancer: A Pooled Analysis of the Phase III VISNÚ-1 and Phase II VISNÚ-2 Randomized Trials

BackgroundThe bCTC count is a well-established prognostic biomarker in mCRC, as well as in other tumor types. The aim of this analysis was to evaluate the prognostic/predictive role of the bCTC count (≥3 vs. <3) in previously untreated mCRC. Patients and MethodsThe study involved 589 untreated mCRC patients included in the intention-to-treat population of 2 randomized clinical trials (phase III VISNU-1 [NCT01640405] and phase II VISNU-2 [NCT01640444] studies). ResultsOf the 589 patients, 349 (59.2%) had bCTC≥3 and 240 (40.7%) had bCTC<3. Multivariate analysis showed that the bCTC count is an independent prognostic factor for overall survival (OS) (HR 0.59, 95% CI 0.48-0.72; P = 0.000) and potential for progression-free survival (PFS) (P = 0.0549). Median OS was 32.9 and 19.5 months in patients with bCTC<3 and bCTC≥3 (P <0.001), respectively. This effect was also observed comparing OS in RASwt patients from both studies. Other prognostic factors were: ECOG-PS, primary tumor site, number of metastatic sites and surgery of the primary tumor. Median OS was lower for patients treated with anti-VEGF versus anti-EGFR (22.3 vs. 33.3 months, P <0.0001) while there were no significant differences in PFS according to the targeted treatment received. ConclusionThis post-hoc analysis of 2 randomized studies confirms the poor prognosis of patients with bCTC≥3 but this is not associated with other adverse independent prognostic factors such as RAS/BRAF mutations.

WJOG13219G: The Efficacy and Safety of FOLFOXIRI or Doublet plus Anti-VEGF Therapy in Previously Untreated BRAFV600E Mutant Metastatic Colorectal Cancer: A Multi-Institutional Registry-Based Study (BRACELET Study)

BackgroundThe real-world survival benefit of FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan) plus anti-VEGF therapy (Triplet) over doublet chemotherapy (Doublet) remains controversial in patients with BRAFV600E mutant metastatic colorectal cancer (mCRC). Patients and MethodsWJOG13219G was a multicenter, retrospective, registry-based study of patients with BRAFV600E mutant mCRC who received first-line triplet or doublet chemotherapy from January 2014 to December 2019 in Japan. Inverse probability of treatment weighting (IPTW) was used to adjust for patient background. ResultsThe analysis included 79 and 91 patients in the Triplet and Doublet groups, respectively. The Triplet group was significantly younger and had better performance status. No statistical difference was noted in progression-free survival (PFS; HR, 0.82; 95% CI, 0.60–1.13; P = .22) and overall survival (OS; HR, 0.88; 95% CI, 0.62–1.25; P = .48) between both groups. IPTW analysis also showed no difference between the 2 groups in PFS (HR, 0.86; 95% CI, 0.69–1.08; P = .20) and OS (HR, 0.93; 95% CI, 0.73–1.20; P = .59). The Triplet and Doublet groups had an objective response rate of 53% and 41%, respectively (P = .10). At least one grade 3 or 4 adverse event was seen in 51 (65%) and 43 (47%) patients in the Triplet and Doublet groups, respectively, with the incidence of neutropenia being significantly higher in the former. ConclusionTriplet therapy had no survival benefit versus doublet therapy in the overall and IPTW cohorts or specific subgroups for real-world patients with BRAFV600E mutant mCRC.

First-line fluoropyrimidine plus bevacizumab followed by irinotecan-escalation versus initial fluoropyrimidine, irinotecan and bevacizumab in patients with metastatic colorectal cancer – Final survival and per-protocol analysis of the randomised XELAVIRI trial (AIO KRK 0110)

BackgroundThe randomised open-label phase III XELAVIRI trial failed to demonstrate non-inferiority of the sequential application of fluoropyrimidine plus bevacizumab followed by additional irinotecan at first progression (Arm A) versus initial combination of all agents (Arm B) for untreated metastatic colorectal cancer in the initial analysis of time-to-failure-of-strategy (TFS, 90% confidence boundary of 0.8). Here, we evaluate efficacy in the full analysis set (FAS), the per-protocol set, in addition to age-related and molecular subgroups. MethodsMedian TFS, overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan–Meier method and log-rank test. Cox regression models assessed hazard ratios (HRs) and confidence intervals (CIs) (TFS: 90%; OS, PFS: 95%). ResultsOf 421 patients, 390 (92.6%), 391 (92.9%) and 357 (84.8%) events for TFS, OS and PFS were observed in the FAS with a median follow-up of 54.2 months (Arm A) versus 52.9 months (Arm B). Non-inferiority of sequential treatment for TFS was missed in the FAS (HR 0.93; 90% CI, 0.79–1.10; P = 0.482) and not shown in the per-protocol set (HR 0.93; 90% CI, 0.75–1.13, P = 0.433). Formal non-inferiority for TFS was observed for patients older than 70 years (HR 1.06; 90% CI, 0.80–1.41; P = 0.670) and patients with RAS mutant tumours (HR 1.12; 90% CI, 0.87–1.43; P = 0.465). In RAS/BRAF wild-type tumours, combination treatment was significantly superior to sequential therapy in all end-points. ConclusionsIn the overall population, XELAVIRI just missed to demonstrate the non-inferiority of sequential compared to combination therapy for TFS. However, the non-inferiority of sequential treatment was observed in elderly patients and RAS mutant tumours. Trial registrationTrial registration ID (clinicaltrials.gov) NCT01249638.

MO42-6 The clinical and molecular landscape of focal MET-amplified metastatic colorectal cancer patients

MET amplification (amp) is rare in untreated metastatic colorectal cancer (mCRC), but cell-free DNA (cfDNA) analysis identifies it in 20% with anti-EGFR monoclonal antibody (mAb) refractory disease. We previously reported that cfDNA could detect focal versus non-focal MET amp in mCRC, and focal MET amp may be a better predictor of benefit from a MET inhibitor (Ann Oncol.2019; 30(suppl_5): abstr3022). However, the clinical and molecular landscape of MET amp mCRC is not well understood.

Immunotherapy in colorectal cancer: an unmet need deserving of change.

The efficacy of immunotherapy in colorectal cancer is currently restricted to patients with metastatic colorectal cancer presenting deficient mismatch repair (dMMR) or microsatellite instability (MSI). So far, neither immunotherapy agents as monotherapy nor immunotherapy-based combinations have shown benefit for metastatic colorectal cancer with proficient mismatch repair (pMMR) or microsatellite stability (MSS), which are mostly immunologically cold. 1 Ganesh K Stadler ZK Cercek A et al. Immunotherapy in colorectal cancer: rationale, challenges and potential. Nat Rev Gastroenterol Hepatol. 2019; 16: 361-375 Crossref PubMed Scopus (480) Google Scholar However, the immune landscape of colorectal cancer is complex and heterogenous, and the development of these treatment strategies must consider, not only the histological context, but also its potential distinctive features. 2 Guinney J Dienstmann R Wang X et al. The consensus molecular subtypes of colorectal cancer. Nat Med. 2015; 21: 1350-1356 Crossref PubMed Scopus (2403) Google Scholar In The Lancet Oncology, Carlotta Antoniotti and colleagues 3 Antoniotti C Rossini D Pietrantonio F et al. Upfront FOLFOXIRI plus bevacizumab with or without atezolizumab in the treatment of patients with metastatic colorectal cancer (AtezoTRIBE): a multicentre, open-label, randomised, controlled, phase 2 trial. Lancet Oncol. 2022; (published online May 27.)https://doi.org/10.1016/S1470-2045(22)00274-1 Summary Full Text Full Text PDF PubMed Google Scholar report the results of the addition of atezolizumab to front-line FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan) plus bevacizumab (the atezolizumab group) compared with FOLFOXIRI plus bevacizumab (the control group) in patients with metastatic colorectal cancer from the phase 2 AtezoTRIBE trial, irrespective of tumour microsatellite status. The superiority of FOLFOXIRI plus bevacizumab over FOLFIRI (leucovorin, fluorouracil, and irinotecan) plus bevacizumab as front-line treatment of metastatic colorectal cancer was previously demonstrated in the phase 3 TRIBE trial. Drawing from this rationale, in this multicentre, academic study, the investigators raised the question of whether the restoration of the anticancer immunity through inhibition of the PD-1–PD-L1 axis enhances efficacy of an upfront intensified chemotherapy regimen. The underlying hypothesis was that chemotherapy can induce tumour cells to release more neoantigens, leading to immunogenic cell death and activation of CD8 T lymphocytes, while bevacizumab-mediated vasculature normalisation upon VEGF or VEGFR blockade promotes increased tumour-infiltrating lymphocytes and activation of effector immune cells. 4 Kanterman J Sade-Feldman M Biton M et al. Adverse immunoregulatory effects of 5FU and CPT11 chemotherapy on myeloid-derived suppressor cells and colorectal cancer outcomes. Cancer Res. 2014; 74: 6022-6035 Crossref PubMed Scopus (113) Google Scholar , 5 Terme M Pernot S Marcheteau E et al. VEGFA–VEGFR pathway blockade inhibits tumor-induced regulatory T-cell proliferation in colorectal cancer. Cancer Res. 2013; 73: 539-549 Crossref PubMed Scopus (413) Google Scholar Given that no significant benefit has been derived from the combination of immunotherapy with non-intensified regimens, 6 Grothey A Tabernero J Arnold D et al. Fluoropyrimidine (FP) + bevacizumab (BEV) + atezolizumab vs FP/BEV in BRAFwt metastatic colorectal cancer (mCRC): findings from Cohort 2 of MODUL—a multicentre, randomized trial of biomarker-driven maintenance treatment following first-line induction therapy. Ann Oncol. 2018; 29: viii714-viii715 Google Scholar , 7 Lenz HJ Parikh AR Spigel DR et al. Nivolumab (NIVO) + 5-fluorouracil/leucovorin/oxaliplatin (mFOLFOX6)/bevacizumab (BEV) versus mFOLFOX6/BEV for first-line (1L) treatment of metastatic colorectal cancer (mCRC): phase 2 results from CheckMate 9X8. Proc Am Soc Clin Oncol. 2022; 40 (abstr).: 8 Crossref PubMed Google Scholar the use of FOLFOXIRI is a rational partner in an untreated RAS-mutated enriched metastatic colorectal cancer population. Upfront FOLFOXIRI plus bevacizumab with or without atezolizumab in the treatment of patients with metastatic colorectal cancer (AtezoTRIBE): a multicentre, open-label, randomised, controlled, phase 2 trialThe addition of atezolizumab to first-line FOLFOXIRI plus bevacizumab is safe and improved progression-free survival in patients with previously untreated metastatic colorectal cancer. Full-Text PDF

Phase 3 trial of sequential versus combination treatment in colorectal cancer: The C-cubed study

BackgroundAn optimal treatment strategy using oxaliplatin and bevacizumab for metastatic colorectal cancer has not been defined. We investigated whether the sequential treatment using fluoropyrimidines with bevacizumab followed by the addition of oxaliplatin at first progression was better than a combination treatment using fluoropyrimidines and oxaliplatin with bevacizumab. MethodsIn the sequential treatment, the escalation from fluoropyrimidines plus bevacizumab to fluoropyrimidines plus oxaliplatin with bevacizumab was recommended in case of progressive disease. Time to failure of strategy was the primary end-point, whereas the secondary end-points were overall survival, progression-free survival, overall response rate and safety. ResultsThree hundred patients with previously untreated metastatic colorectal cancer were randomised to receive either the sequential treatment (n = 151) or the combination treatment (n = 149). The sequential treatment was superior to the combination treatment about time to failure of strategy (15.2 months; 95% CI, 12.5–17.2 months vs. 7.8 months: 95% CI, 6.3–9.5 months; P < 0.001). However, the median overall survival was 27.5 (95% CI, 24.4 to 32.7) months in the sequential treatment and 27.0 (95% CI, 22.8 to 36.0) months in the combination treatment (hazard ratio, 0.92; 95% CI, 0.66 to 1.28; P = 0.61). The overall response rate was 33.1% in the sequential treatment arm and 51.7% in the combination treatment. ConclusionsThe findings support the extension of the sequential treatment starting from fluoropyrimidine plus bevacizumab to selected patients who do not need an objective response to the threatening disease.

Genomic Landscape of Primary Tumor Site and Clinical Outcome for Patients with Metastatic Colorectal Cancer Receiving Standard-of-Care Chemotherapy.

Primary tumor site and genomic status are utilized for regimen selection in metastatic colorectal cancer; however, the impact on clinical practice is not well known. We aimed to clarify the impact of primary tumor site and genomic status on clinical practice in metastatic colorectal cancer. The relationship between primary tumor site, genomic alterations, and clinical outcomes was evaluated in patients with untreated metastatic colorectal cancer using real-world data of a prospective observational study, SCRUM-Japan GI-SCREEN with clinical and genomic data set in 1011 patients enrolled from February 2015 to March 2017. Five hundred and sixty-one patients were eligible for this study. Patients with right-sided tumors had a significantly worse survival, left-sided tumors with wild-type RAS had favorable outcomes when treated with anti-epidermal growth factor receptor monoclonal antibodies, and cecum tumors had poor prognosis when treated with bevacizumab. The rate of gene alterations varied considerably depending on the primary site. In addition, gene alterations of KRAS, BRAF, SMAD4, or TP53 had individually different contributions to survival from site to site. KRAS, BRAF, PTEN, or SMAD4 mutations were associated with efficacy of bevacizumab or anti-epidermal growth factor receptor monoclonal antibodies. Primary tumor site is a clinically useful biomarker to predict survival in patients with metastatic colorectal cancer treated with first-line chemotherapy. Moreover, the prognostic or predictive value of several gene alterations by primary tumor site should be considered in clinical practice.

Overall Survival and Progression-Free Survival Comparison of Bevacizumab Plus Chemotherapy Combination Regiment versus Chemotherapy Only Regiment in Previously Untreated Metastatic Colorectal Cancer: Systematic Review and Meta-Analysis

BACKGROUND: Colorectal cancer is the third-most common cancer in the world, in which 15%–25% of patients already had metastatic colorectal cancer (mCRC) at the time of diagnosis. The overall survival (OS) of mCRC is poor with the use of chemotherapy. AIM: This systematic review and meta-analysis aim to examine the outcomes of OS and progression-free survival (PFS) of adding bevacizumab to different chemotherapy regiments compared to chemotherapy regiments only in the treatment of untreated mCRC. METHODS: Literature searching was done in databases such as PubMed, EBSCO, SCOPUS, and ScienceDirect. The primary outcome measured in this systematic review and meta-analysis was OS, while the secondary outcome was PFS. Hazard ratio (HR) was used as the main summary measure with 95% confidence interval (CI). Publication bias was measured using a funnel plot. RESULTS: Literature searching resulted in 11 selected studies, 9 selected for meta-analysis. Addition of bevacizumab showed significant better results in OS (HR 0.83, CI 95% 0.74–0.93; p = 0.002; I2 = 29%) and PFS (HR 0.62, 95% CI 0.51–0.75; p &lt; 0.0001, I2 = 78%). CONCLUSION: The addition of bevacizumab to chemotherapy resulted in better OS and PFS in untreated mCRC. Further studies are needed to confirm PFS benefit from the combination of bevacizumab and chemotherapy due to significant heterogeneity.

Response and Disease Dynamics in Untreated Metastatic Colorectal Cancer With Bevacizumab-Based Sequential vs. Combination Chemotherapy—Analysis of the Phase 3 XELAVIRI Trial

IntroductionEarly tumor shrinkage (ETS), depth of response (DpR), and time to DpR represent exploratory endpoints that may serve as early efficacy parameters and predictors of long-term outcome in metastatic colorectal cancer (mCRC). We analyzed these endpoints in mCRC patients treated with first-line bevacizumab-based sequential (initial fluoropyrimidines) versus combination (initial fluoropyrimidines plus irinotecan) chemotherapy within the phase 3 XELAVIRI trial.MethodsDpR (change from baseline to smallest tumor diameter), ETS (≥20% reduction in tumor diameter at first reassessment), and time to DpR (study randomization to DpR image) were analyzed. We evaluated progression-free survival and overall survival with ETS as stratification parameter according to treatment arm, molecular subgroup, and sex.ResultsIn 370 patients analyzed, a higher rate of ETS (60.9% vs. 43.5%; p = 0.001) and significantly greater DpR (-40.0% vs. -24.7%; p < 0.001) were observed in the initial combination therapy arm. The improvement was pronounced in RAS/BRAF wild-type tumors. ETS correlated with improved survival irrespective of treatment arm (PFS: p < 0.001; OS: p = 0.012) and molecular subgroup (PFS: p < 0.001; OS: p < 0.001). Male patients in contrast to female patients with ETS had survival benefit (PFS: p < 0.001, HR 0.532; OS: p < 0.001, HR 0.574 vs. PFS: p = 0.107; OS: p = 0.965).ConclusionsInitial irinotecan-based combination therapy with bevacizumab improved ETS and DpR in mCRC patients with a particularly high irinotecan sensitivity of RAS/BRAF wild-type tumors. ETS seems to be a suitable prognostic marker for fluoropyrimidine- and bevacizumab-based combinations in mCRC. This finding was rather driven by male patients, potentially indicating that ETS might be less predictive of long-term outcome in an elderly, female population.

433P Durvalumab and tremelimumab in combination with FOLFOX in patients with previously untreated RAS-mutated metastatic colorectal cancer: First results of efficacy at one year for phase II MEDITREME trial

Single agent PD-1/PD-L1 inhibition is not effective in metastatic colorectal cancer (MCRC) with microsatellite stable tumors. Signal of efficacy was shown using anti-PD-L1 and anti CTLA-4 in multitreated patients. FOLFOX regimen could induced immunogenic cell death, leading to a potential positive effect on antitumor immune response.

P-99 Circulating RNA detection, circulating tumor cells count, and molecular tumor profiling in a cohort of untreated metastatic colorectal cancer: A prospective multicenter ancillary study to the randomized VISNÚ trials

P-99 Circulating RNA detection, circulating tumor cells count, and molecular tumor profiling in a cohort of untreated metastatic colorectal cancer: A prospective multicenter ancillary study to the randomized VISNÚ trials

Treatment responses and disease dynamics in patients with untreated metastatic colorectal cancer receiving bevacizumab-based sequential versus combination chemotherapy: Analysis of a phase 3 trial (AIO KRK0110, XELAVIRI study).

3571 Background: Early response parameters such as early tumor shrinkage (ETS), depth of response (DpR), and time to DpR represent exploratory endpoints that may serve as early efficacy endpoints and potential predictors of long-term outcome. We analyzed the association of these endpoints with bevacizumab-based sequential (initial fluoropyrimidines) versus combination (initial fluoropyrimidines plus irinotecan) chemotherapy within a randomized phase III trial. Methods: DpR (change from baseline to smallest tumor diameter), ETS (≥20% reduction in tumor diameter at first reassessment), and time to DpR (study randomization to DpR-image) were analyzed in the XELAVIRI-trial. Moreover, progression-free survival (PFS) and overall survival (OS) were evaluated with ETS as stratification parameter (ETS vs. no ETS) according to treatment arm, molecular subgroup, and sex. Results: 370 patients were available for analysis of early treatment response parameters. A higher rate of ETS (60.9% vs. 43.5%; p = 0.001) and significantly greater DpR (-40.0% vs. -24.7%; p &lt; 0.001) were observed in the initial combination compared to the sequential therapy arm, respectively. The improvement of ETS and DpR was pronounced in the subpopulation of RAS/ BRAF wildtype patients. Male in contrast to female patients significantly benefitted from initial combination treatment in terms of median DpR (male: -40.0% vs. -22.2%; p &lt; 0.001; female: -34.0% vs. -24.4%; p = 0.13) and rate of ETS (male: 64.8% vs. 40.2%; p &lt; 0.001; female: 52.5% vs. 49.3%; p = 0.73). Achievement of ETS correlated with improved survival irrespective of treatment arm (PFS: p &lt; 0.001; OS: p = 0.012) and molecular subgroup (PFS: p &lt; 0.001; OS: p &lt; 0.001). Whereas the survival benefit in male patients achieving ETS was statistically significant (PFS: p &lt; 0.001, HR 0.532 (0.409-0.692); OS: p &lt; 0.001, HR 0.574 (0.437-0.756)), there were no significant differences in PFS (p = 0.107) and OS (p = 0.965) of female patients depending on ETS. Conclusions: In the XELAVIRI trial, initial irinotecan-based combination therapy with bevacizumab improves ETS and DpR in mCRC patients. Improvement in early response parameters appears pronounced in patients with RAS/ BRAF wildtype tumors suggesting a high sensitivity to irinotecan-based treatment. ETS was predictive of PFS and OS regardless of treatment arm. This finding was rather driven by male than female patients, potentially indicating that ETS might be less predictive of long-term outcome in an elderly, female population.

Black Raspberries Suppress Colorectal Cancer by Enhancing Smad4 Expression in Colonic Epithelium and Natural Killer Cells.

Innate immune cells in the tumor microenvironment have been proposed to control the transition from benign to malignant stages. In many cancers, increased infiltration of natural killer (NK) cells associates with good prognosis. Although the mechanisms that enable NK cells to restrain colorectal cancer (CRC) are unclear, the current study suggests the involvement of Smad4. We found suppressed Smad4 expression in circulating NK cells of untreated metastatic CRC patients. Moreover, NK cell-specific Smad4 deletion promoted colon adenomas in DSS-treated ApcMin/+ mice and adenocarcinomas in AOM/DSS-treated mice. Other studies have shown that Smad4 loss or weak expression in colonic epithelium associates with poor survival in CRC patients. Therefore, targeting Smad4 in both colonic epithelium and NK cells could provide an excellent opportunity to manage CRC. Toward this end, we showed that dietary intervention with black raspberries (BRBs) increased Smad4 expression in colonic epithelium in patients with FAP or CRC and in the two CRC mouse models. Also, benzoate metabolites of BRBs, such as hippurate, upregulated Smad4 and Gzmb expression that might enhance the cytotoxicity of primary human NK cells. Of note, increased levels of hippurate is a metabolomic marker of a healthy gut microbiota in humans, and hippurate also has antitumor effects. In conclusion, our study suggests a new mechanism for the action of benzoate metabolites derived from plant-based foods. This mechanism could be exploited clinically to upregulate Smad4 in colonic epithelium and NK cells, thereby delaying CRC progression.

Clinical impact of primary tumour location, early tumour shrinkage, and depth of response in the treatment of metastatic colorectal cancer with first-line chemotherapy plus cetuximab or bevacizumab

The primary tumour location is an important prognostic factor for previously untreated metastatic colorectal cancer (mCRC). However, the predictive efficacies of primary tumour location, early tumour shrinkage (ETS), and depth of response (DpR) on mCRC treatment has not been fully evaluated. This study aimed to investigate the predictive efficacies of these traits in mCRC patients treated with first-line 5-fluorouracil-based chemotherapy plus biologic agents, namely, cetuximab and bevacizumab. This was a retrospective analysis of the medical records of 110 patients with pathology-documented unresectable mCRC. Patients with left-sided mCRC receiving any first-line regimen showed better overall survival (OS) than those with right-sided mCRC [33.3 vs 16.3 months; hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27–0.74; p < 0.001]. In patients with left-sided tumours, treatment with chemotherapy plus cetuximab yielded longer OS than chemotherapy plus bevacizumab (50.6 vs 27.8 months, HR 0.55; 95% CI 0.32–0.97; p = 0.0378). mCRC patients with ETS and high DpR showed better OS than those lacking ETS and with low DpR (33.5 vs 19.6 months, HR 0.50, 95% CI 0.32–0.79, p = 0.023 and 38.3 vs 19.0 months, HR 0.43, 95% CI 0.28–0.68, p < 0.001, respectively). Moreover, ETS and/or high DpR achieved in patients with right-sided mCRC receiving chemotherapy plus cetuximab were associated with significantly better OS than in those lacking ETS and with low DpR (34.3 vs 10.4 months, HR 0.19, 95% CI 0.04–0.94, p = 0.025 and 34.3 vs 10.4 months, HR 0.19, 95% CI 0.04–0.94, p = 0.0257, respectively). Taken together, our study demonstrates that primary tumour location is not only a well-known prognostic factor but also a relevant predictive factor in patients with mCRC receiving chemotherapy plus cetuximab. Additionally, both ETS and DpR could predict treatment outcomes and also potentially guide cetuximab treatment even in right-sided mCRCs.

A phase II study of FOLFOXIRI plus bevacizumab as initial chemotherapy for patients with untreated metastatic colorectal cancer: TRICC1414 (BeTRI)

PurposeFOLFOXIRI plus bevacizumab is regarded as a first-line therapeutic option for selected patients with metastatic colorectal cancer (mCRC). Our aim was to assess the efficacy and safety of induction treatment with FOLFOXIRI plus bevacizumab in patients with untreated mCRC harboring UGT1A1 wild (*1/*1), or single-hetero (*1/*6 or *1/*28) genotypes.MethodsTwelve cycles of FOLFOXIRI plus bevacizumab were administered to patients with untreated mCRC. The primary endpoint was the overall response rate (ORR) assessed by central independent reviewers. Secondary endpoints included time to treatment failure (TTF), progression-free survival (PFS), overall survival (OS), relative dose intensity (RDI), R0 resection rate, and safety. The exploratory objectives were early tumor shrinkage (ETS) and depth of response (DoR).ResultsOf the 47 patients enrolled, 46 and 44 patients were eligible for the safety and efficacy analysis, respectively. The primary endpoint was met. The ORR was 63.6% (95% CI 47.8–77.6). At a median follow-up of 25.4 months, median TTF, PFS, and OS was 8.1, 15.5, and 34.4 months, respectively. The median RDI of 5-fluorouracil, irinotecan, oxaliplatin, and bevacizumab was 72, 69, 62, and 71%, respectively. R0 resection rate was 22.7%. Grade 3 or higher adverse events (≥ 10%) included neutropenia (65.2%), febrile neutropenia (26.1%), leukopenia (23.9%), anorexia (10.9%), nausea (10.9%), and diarrhoea (10.9%). No treatment-related deaths were observed. ETS and DoR were 70.5 and 45.4%, respectively.ConclusionsFOLFOXIRI plus bevacizumab induction treatment of Japanese patients was shown to be beneficial and manageable, although caution is required since the treatment causes febrile neutropenia.

434P Impact of molecular markers status on treatment effects comparing EGFR and VEGF monoclonal antibodies (mAbs) in untreated metastatic colorectal cancer (mCRC): Pooled individual patient data (IPD) analysis of randomized trials from the ARCAD database

Background Chemotherapy combined with either VEGF or EGFR targeting mAbs improves survival of patients (pts) with mCRC. In clinical practice, the selection of antibody may take into account multiple factors, including RAS/BRAF mutation status and tumour sidedness. Methods IPD from 2 randomized first-line trials with head-to-head comparison of chemo+EGFRmAb v chemo+VEGFmAb in mCRC were pooled. Biomarker subpopulations (see table) were analysed. Overall survival (OS) and progression-free survival (PFS) were compared between groups by Cox model, stratified by studies and adjusted by age, gender and performance status. Treatment effects were estimated by adjusted hazard ratio (HRadj) and 95% confidence interval (CI). Within each biomarker subset, mAb efficacy was explored according to type of chemo, gender, sidedness and site of metastasis. Interaction tests were performed. P-values < 0.01 were considered statistically significant to account for multiple comparisons. Results 1967 pts from 2 studies with data available for ≥ 1 biomarker were analysed. For the KRAS and NRAS MT groups, PFS favoured VEGF targeting (median 12.0 v 8.0 mos in KRAS MT, median 12.9 v 8.1 mos in NRAS MT), but OS did not differ significantly (see table). No difference in PFS or OS was observed in the BRAF MT or triple WT groups. Exploratory analyses of sidedness demonstrated inferior survival with EGFR mAbs (vs. VEGFmAb) in triple WT tumors on the right side of the colon (OS: HRadj 1.61, p=.056, pinteraction .099; PFS: HRadj 2.39, p=.0007, pinteraction .041).

SO-28 A randomized phase II trial of mFOLFOX6-based standard of care alone or in combination with Ad-CEA vaccine plus avelumab in patients with previously untreated metastatic colorectal cancer

The majority of metastatic colorectal cancer (mCRC) pts have MMR proficient (pMMR) tumors and do not respond to immune checkpoint inhibitors (ICI). Therapeutic cancer vaccines can generate tumor-associated antigen (Ag) specific T cells, a situation in which preclinical data suggest ICI may be more biologically relevant. In light of the immunomodulatory properties of chemotherapy, we hypothesized that avelumab (Av) + CEA-targeted adenoviral vaccine (Ad5) + standard of care (SOC) mFOLFOX6 + bevacizumab would have synergistic anti-tumor activity in pMMR mCRC.