Real-world effectiveness and safety of trifluridine/tipiracil plus bevacizumab in metastatic colorectal cancer: A retrospective observational study using an administrative database

44

Background: Trifluridine/tipiracil (FTD/TPI) and regorafenib (REG) are standard of care for refractory metastatic colorectal cancer (mCRC). Several phase II trials of FTD/TPI plus bevacizumab (BEV) have been conducted, showing promising efficacy with manageable safety, and it is widely used for patients with refractory mCRC in Japan. No result has been reported for large-scale real-world data directly comparing FTD/TPI plus BEV with FTD/TPI or REG monotherapy. Here, we evaluated the efficacy and safety of FTD/TPI plus BEV in real-world clinical practice. Methods: We used a nationwide claims database provided by Medical Data Vision Co., Ltd. (Tokyo, Japan) in Japan. Eligible patients were aged 20 years or older in mCRC who received their first dose of FTD/TPI or REG between May 2014 and January 2021. The primary outcome was overall survival (OS) in a propensity score matching (PSM) population that was performed matching using a 1:1 ratio for FTD/TPI plus BEV and control group (FTD/TPI or REG) by propensity score. To enhance robustness, sensitivity analyses of OS were performed using the inverse probability treatment weighted (IPTW) approach and the analysis in all eligible population. Main secondary outcomes were OS for subgroups, time to treatment discontinuation (TTD), adverse events (assessed in all eligible population), and post-treatment. Results: The eligible population was 2,369 for FTD/TPI plus BEV and 9,318 for control group (FTD/TPI: 6,500 and REG: 2,818). The PSM population was 1,787 for FTD/TPI plus BEV and 1,787 for control group (FTD/TPI: 1,252 and REG: 535). Median OS (mOS) was 17.0 months for FTD/TPI plus BEV and 11.6 months for control group (HR: 0.70; 95% CI: 0.63–0.78; P < 0.001) in PSM population. Similarly, mOS was longer for FTD/TPI plus BEV compared to that for control group in IPTW analyses (HR: 0.68; 95% CI: 0.65–0.71; P < 0.001) and in all eligible population (HR: 0.68; 95% CI: 0.63–0.73; P < 0.001). In all eligible population, mOS were 17.6 months for FTD/TPI plus BEV and 12.6 months for control group (FTD/TPI: 12.9 months and REG: 12.1 months). Median TTD was 101 days for FTD/TPI plus BEV and 56 days for control group in PSM population (Wilcoxon rank-sum test P < 0.001). The incidence of hand-foot syndrome was significantly higher in REG compared with that in FTD/TPI plus BEV (Fisher's Exact test P < 0.001. Leukopenia incidence was significantly higher in FTD/TPI plus BEV than that in REG (Fisher's Exact test P < 0.001. Granulocyte colony-stimulating factor was administered to 20.6%, 16.5%, and 1.1% of patients in FTD/TPI plus BEV, FTD/TPI, and REG, respectively. Conclusions: The real-world data showed that FTD/TPI plus BEV had significantly longer OS and TTD than FTD/TPI or REG in mCRC. Thus, FTD/TPI plus BEV may be a favorable regimen for refractory mCRC in clinical practice.

Treatment efficacy of ramucirumab-containing chemotherapy in patients with alpha-fetoprotein producing gastric cancer

BACKGROUND

Alpha-Fetoprotein Producing Gastric Cancer (AFPGC) is an aggressive subgroup of gastric cancer. Recently ramucirumab has shown survival benefits in hepatocellular carcinoma, but only in those with higher Alpha-Fetoprotein (AFP) levels. However, the efficacy of ramucirumab-containing chemotherapy in AFPGC remains unclear.

METHODS

We retrospectively assessed 352 patients who received ramucirumab-containing chemotherapy between June 2015 and December 2019. AFPGC was defined when serum AFP levels were elevated at diagnosis and correlated with the disease state during treatment. Non-AFPGC was defined when serum AFP levels were normal at diagnosis.

RESULTS

Among the 352 patients, 28 patients were defined as AFPGC and 246 patients were defined as non-AFPGC. AFPGC was characterized by high frequency of liver metastasis and low frequency of peritoneal metastasis compared to non-AFPGC. Ramucirumab containing chemotherapy showed higher response rates in AFPGC (39.1% vs 24.8%, p = 0.198) and disease control rates (86.9% vs 61.5%, p = 0.028) than those of non-AFPGC, respectively. Median progression-free survival (PFS) was 5.5 months (95%CI 3.9-7.1) in AFPGC and 4.0 months (95%CI 3.6-4.6) in non-AFPGC (HR: 0.91, 95% CI 0.61-1.36, p = 0.66), and median overall survival (OS) was 10.7 months (95% CI 7.4-20.8) in AFPGC and 9.2 months (95% CI 8.1-10.4) in non-AFPGC (HR: 0.72, 95% CI 0.48-1.08, p = 0.11), respectively. In multivariate analysis, AFPGC was not a negative prognostic factor both for PFS and OS.

CONCLUSION

Ramucirumab containing chemotherapy showed higher response and comparable survival in AFPGC compared to those of non-AFPGC. Considering the generally poor prognosis of AFPGC, ramucirumab-containing chemotherapy might be a promising treatment option in AFPGC.

Implementation of microsatellite instability testing for the assessment of solid tumors in clinical practice

BACKGROUND

In Japan, microsatellite instability (MSI) testing for solid tumors was introduced in clinical practice in December 2018. Although immune checkpoint inhibitors (ICIs) are established standards of care for patients with MSI-high tumors, the status of implementing MSI testing in clinical practice remains unclear.

METHODS

We retrospectively reviewed the medical records of patients with solid tumors who underwent MSI testing between January 2019 and December 2020 at our institution.

RESULTS

In total, 1,052 MSI tests were performed in 1,047 patients. Regardless of specimen volume and condition, the MSI status was successfully determined in 1,041 (99.0%) tests, encompassing 27 tumor types (microsatellite stable [MSS] or MSI-low: n = 991 [95.2%] and MSI-high: n = 50 [4.8%]). Patients whose specimens were fixed with 20% neutral buffered formalin (NBF) and who had specimens with prolonged storage (98.4% and 95.4%) showed lower success rates than those whose specimens were fixed with 10% NBF and who had specimens with nonprolonged storage (100.0% and 99.6%), respectively. The prolonged turnaround time (TAT) in MSI-high cases (median TAT: 24 days) was a critical issue that directly resulted in treatment delay. Of the 50 patients with MSI-high tumors, 24 (48.0%) received ICIs and 34 (68.0%) were referred to the Department of Clinical Genetic Oncology where 6 (12.0%) patients were diagnosed with Lynch syndrome.

CONCLUSIONS

MSI testing was successfully performed for various types of tumors and specimens in clinical practice. Our study results identified certain issues associated with the clinical implementation of MSI testing, including optimal specimen selection, extended TAT in MSI-high cases, and awareness of hereditary tumors.

Druggable gene alterations in Japanese patients with rare malignancy

Without a current standard of care, patients with rare malignancy are subjected to precision oncology with next-generation sequencing to identify a course of treatment. We sought to establish the clinical relevance of comprehensive genomic profiling (CGP) among patients with rare malignancy. Rare malignancy was defined using the Rare Cancers in Europe definition (<6 cases per 100,000 individuals). We analyzed gene mutations, fusions, tumor mutational burden (TMB), and microsatellite instability (MSI) status. Level A gene alterations, categorized using Clinical Interpretations of Variants in Cancer and MD Anderson Knowledge Base for Precision Oncology, were considered druggable. Rare malignancy accounted for 149 (45%) cases, with female genital cancers (32%) most common. Among the rare malignancy cases, we identified a lower frequency of mutation in TP53 (41% vs. 60%, P<0.001), KRAS (13% vs. 43%, P<0.001) and APC (3% vs. 25%, P<0.001), and a higher frequency of ARID1A mutation (14% vs. 6%, P=0.03), as compared with common malignancies. TMB-high and MSI-high cases were found in 8% and 2% of cases, respectively. Druggable alterations were detected in 37 patients with rare malignancy; this percentage tended to be higher than that for patients with common malignancies (25% vs. 17%, P=0.08). Common druggable alterations were BRAF V600E, ERBB2 amplification, PIK3CA E542K, and BRCA1/2 variant. Five of the 37 patients with druggable alterations received genome-driven treatment. There was no significant difference in overall survival between the rare and common malignancy groups. Our results provide clues for future clinical development and treatment success among Japanese patients with rare cancers.

Multicentre single-arm phase II trial evaluating the safety and effiCacy of Panitumumab and iRinOtecan in NeoRAS Wild-type mEtaStatic colorectal cancer patientS (C-PROWESS trial): study protocol

INTRODUCTION

A new concept of 'NeoRAS wild-type (WT)', which means conversion of RAS status from RAS mutant to RAS WT after treatment, has been reported. Previous observational and proof-of-concept studies have demonstrated the efficacy of epidermal growth factor receptor inhibitors in patients with NeoRAS WT metastatic colorectal cancer (mCRC). Moreover, posthoc biomarker analyses of these studies have suggested that not only the RAS status in the circulating tumour DNA (ctDNA) but also other gene mutational status may be useful as biomarkers of epidermal growth factor receptor inhibitors for NeoRAS WT mCRC.

METHODS AND ANALYSIS

This trial is a multicentre, single-arm, phase II trial to assess the efficacy and safety of panitumumab plus irinotecan therapy for patients with NeoRAS mCRC. The key eligibility criteria include RAS mutant mCRC initially proven in tumour tissue refractory or intolerant to fluoropyrimidine, oxaliplatin and irinotecan; RAS WT in ctDNA (defined as plasma mutant allele frequencies of all RAS ≤0.1%) within 28 days before enrolment and Eastern Cooperative Oncology Group performance status ≤2. The primary endpoint is the response rate. The target sample size is 30 patients. Biomarker analyses are planned to be performed using next-generation sequencing-based ctDNA analysis.

ETHICS AND DISSEMINATION

This study was approved by the certified review board of National Cancer Center Hospital. The main results of the trial will be presented in international meetings and in medical journals.

TRIAL REGISTRATION NUMBER

s031210565.

Clinical Usefulness of Postoperative Serum Carcinoembryonic Antigen in Patients with Colorectal Cancer with Liver Metastases

BACKGROUND

Colorectal cancer with liver metastasis (CLM) has high postoperative recurrence rates; therefore, optimizing perioperative treatment is imperative. Postoperative carcinoembryonic antigen (CEA) can aid in detecting minimal residual disease in colon cancer following curative resection. This study aimed to identify the potential role of serum CEA following liver resection in patients with CLM.

METHODS

This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2004 to 2018 and enrolled patients with CLM who underwent complete resection of primary tumors and CLM. Associations between perioperative CEA levels and characteristics of recurrence were investigated.

RESULTS

Recurrence was detected during a median follow-up period of 90.1 months in 343 (54.2%) out of 633 analyzed patients. Patients in the postoperative CEA level > 5 ng/ml group had a significantly higher recurrence rate (75.7% versus 50.0%, p < 0.01) and shorter time until recurrence (4.4 versus 36.9 months, p < 0.01) than those in the postoperative CEA level ≤ 5 ng/ml group. Multivariate analysis revealed that postoperative CEA level > 5 ng/ml was an independent predictor, with hazard ratios of 2.77 (p < 0.01) for recurrence-free survival (RFS) and 3.18 (p < 0.01) for overall survival (OS). Additionally, RFS was significantly shorter among patients in the postoperative CEA level > 5 ng/ml group who did not have normalized CEA levels following adjuvant chemotherapy than among those in the normalized CEA group.

CONCLUSIONS

The postoperative and post-adjuvant chemotherapy CEA levels in the CEA level > 5 ng/ml group may be predictors of RFS and OS.

Clinical Activity of Mitogen-Activated Protein Kinase-Targeted Therapies in Patients With Non-V600 BRAF-Mutant Tumors

PURPOSE

Non-V600 mutations comprise approximately 35% of all BRAF mutations in cancer. Many of these mutations have been identified as oncogenic drivers and can be classified into three classes according to molecular characteristics. Consensus treatment strategies for class 2 and 3 BRAF mutations have not yet been established.

METHODS

We performed a systematic review and meta-analysis with published reports of individual patients with cancer harboring class 2 or 3 BRAF mutations from 2010 to 2021, to assess treatment outcomes with US Food and Drug Administration-approved mitogen-activated protein kinase (MAPK) pathway targeted therapy (MAPK TT) according to BRAF class, cancer type, and MAPK TT type. Coprimary outcomes were response rate and progression-free survival.

RESULTS

A total of 18,167 studies were screened, identifying 80 studies with 238 patients who met inclusion criteria. This included 167 patients with class 2 and 71 patients with class 3 BRAF mutations. Overall, 77 patients achieved a treatment response. In both univariate and multivariable analyses, response rate and progression-free survival were higher among patients with class 2 compared with class 3 mutations, findings that remain when analyses are restricted to patients with melanoma or lung primary cancers. MEK ± BRAF inhibitors demonstrated greater clinical activity in class 2 compared with class 3 BRAF-mutant tumors than BRAF or EGFR inhibitors.

CONCLUSION

This meta-analysis suggests that MAPK TTs have clinical activity in some class 2 and 3 BRAF-mutant cancers. BRAF class may dictate responsiveness to current and emerging treatment strategies, particularly in melanoma and lung cancers. Together, this analysis provides clinical validation of predictions made on the basis of a mutation classification system established in the preclinical literature. Further evaluation with prospective clinical trials is needed for this population.

Abstract 6027: Layered 3D co-cultured tumor model including vascularized stromal tissue may reflect drug sensitivities in vivo tumor

Background: Multiple 3D culture models have been reported as a superior tumor model than 2D culture. The importance of interaction between cancer and stromal cells has been widely recognized in tumor progression and resistance to treatment. Therefore, ex vivo model recapturing the tumor microenvironment is needed to evaluate the drug efficacy under the condition imitating the patient tumor tissue. Purpose: We developed a unique 3D co-cultured tumor model with stromal tissues containing a microvascular network. Here, we investigated drug sensitivity in conventional 2D culture, our 3D co-cultured model and in vivo tumor.

Methods: Drug sensitivity and gene expression on our model were evaluated using patient-derived cancer cells (PDC) established from colorectal cancer (CRC) patients in JFCR. The characteristics were compared with those of conventional 2D cultured cells or patient-derived xenograft (PDX).

Results: In our 3D model, the drug sensitivities tended to be decreased in comparison with those of 2D. However, some drugs presented potent efficacy in our 3D model rather than 2D, and such drugs showed significant tumor growth suppression or tumor regression in vivo. Transcriptome profiles of our 3D model showed relatively higher similarity to those of in vivo tumors than those of 2D.

Conclusion: Our study proposed the unique 3D co-cultured tumor model which may enable more accurate evaluation of drug sensitivities reflecting the in vivo circumstances.

Citation Format: Yuki Takahashi, Shiro Kitano, Eiji Shinozaki, Satoshi Nagayama, Ryohei Katayama, Naoya Fujita. Layered 3D co-cultured tumor model including vascularized stromal tissue may reflect drug sensitivities in vivo tumor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6027.

Abstract 5735: Druggable gene alterations in Japanese patients with rare malignancy

Background: In the absence of a current standard of care, precision oncology with next-generation sequencing provides an important therapeutic option for patients with rare malignancy. Here, we sought to establish the clinical relevancy of comprehensive genomic profiling (CGP) for patients with rare malignancy.

Methods: We reviewed 341 patients who underwent CGP (FoundationOne CDx; OncoGuide NCC OncoPanel System)in our institution between 2019 and 2021. Cases were classified as common or rare malignancy based on the Rare Cancers in Europe (RARECARE) definition (incidence of &lt;6 cases per 100,000 individuals). We analyzed the genomic features in the rare malignancy cohort, including gene mutations, gene fusions, tumor mutational burden (TMB), and microsatellite instability (MSI) status. Gene variants, amplifications, and fusions categorized as evidence level A using Clinical Interpretations of Variants in Cancer (CIViC) and MD Anderson Knowledge Base for Precision Oncology were considered as druggable alterations. CGP testing was used to calculate overall survival (OS) to death or at the last follow-up.

Results: With the exception of 7 unclassifiable cases, rare malignancy accounted for 149 of the 334 cases (45%), with the most common being female genital cancers (32%), followed by digestive cancers (24%), sarcoma (16%), and others (28%). Many (83%) of the patients with rare malignancy harbored at least one pathogenic/likely-pathogenic variant. The commonly mutated genes were TP53 (41%), PIK3CA (20%), ARID1A (14%), and KRAS (13%). ERBB2amplification was detected in 6% of patients (median copy number, 8). Gene fusion in EWSR1 was found in 4% of patients (sarcoma) and in FGFR2 in 1% (cholangiocarcinoma and salivary duct carcinoma). TMB-high (≥10 mut/Mb) and MSI-high cases were found in 8% and 2% of cases, respectively. Druggable alterations were detected in 36 patients; this percentage was not significantly different to that of common malignancy (24% vs. 17%, P=0.10). The common druggable alterations were BRAF V600E (n=10), ERBB2 amplification (n=9), PIK3CA E542K (n=6), and BRCA1/2 variant (n=6). There was no significant difference in OS between the rare and common malignancy groups (1-year OS rate: 62% vs. 46%, P=0.24).

Conclusion: In this study, the ratio of rare malignancy was higher than that typically found in previous epidemiological studies (about 20%-25%). We observed no adverse impact for OS, which might be due to the high number of patients (n=48) with intractable pancreatic cancer. Remarkably, &gt;20% of patients harbored a potential druggable alteration. Our results suggest the clinical relevance of CGP for patients with rare malignancy, and its potential utility to provide clues for future clinical development.

Citation Format: Akihiro Ohmoto, Naomi Hayashi, Ippei Fukada, Masumi Yamazaki, Mayu Yunokawa, Akiyoshi Kasuga, Eiji Shinozaki, Arisa Ueki, Akiko Tonooka, Kengo Takeuchi, Seiichi Mori, Kazuma Kiyotani, Shunji Takahashi. Druggable gene alterations in Japanese patients with rare malignancy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5735.

Clinical impact of DNA methylation status on first-line antiepidermal growth factor receptor treatment in patients with metastatic colorectal cancer

3528

Background: The CpG island methylator phenotype (CIMP), important for carcinogenesis, is a predictor of prognosis and chemotherapy sensitivity in colorectal cancer. However, there is a lack of consensus of CIMP markers, and thus, more comprehensive methylation markers are required to reliably predict the clinical outcomes. Previously, we reported that genome-wide DNAmethylation statuscould predict the effect of epidermal growth factor receptor (EGFR) inhibitors more accurately than previously reported methylation classifications (Ouchi et al. Cancer Sci 2015). Moreover, we had developed a DNA methylation assay based on MethyLight to reflect genome-wide DNA methylation status and reported its usefulness in predicting prognosis in patients with metastatic colorectal cancer (mCRC) treated with EGFR inhibitors as a third-line chemotherapy (Ouchi et al. Cancer Sci 2022). This study aimed to clarify the effects of genome-wide DNA methylation status on clinical outcomes in patients with mCRC treated with first-line EGFR inhibitors. Methods: We enrolled 241 patients with mCRC, who received chemotherapy plus EGFR inhibitors as a first-line treatment, and analyzed the associations between genome-wide DNA methylation status using a novel comprehensive methylation marker panel and clinical outcomes and evaluated the predictive power and value of the methylation status. Results: Total 169 patients were included in the final analyses. The frequency of highly methylated CRC (HMCC) was 8.9% (15/169). The characteristics of patients with HMCC included right-sided primary tumor location (P = 0.042), undifferentiated histology (P = 0.047), and BRAFV600E mutation (P < 0.001). Patients with HMCC showed worse clinical outcomes than those with low methylated CRC in terms of response rate (P = 0.017), progression-free survival (PFS; P = 0.004), and overall survival (P = 0.019). In the multivariate analysis, peritoneal metastasis (Hazard ratio (HR): 2.24, P = 0.017), methylation status (HR: 3.04, P = 0.037), and BRAFV600E mutations (HR: 5.83, P = 0.0001) were independent factors for shorter PFS. Conclusions: Genome-wide DNA methylation status may be an independent predictor of first-line EGFR inhibitors in patients with mCRC.

Real-World Data Analysis of Second-Line Antiangiogenic Targeted Treatments Following Anti-Epidermal Growth Factor Receptor Monoclonal Antibodies and First-Line FOLFOX for Patients with Metastatic Colorectal Cancer

Introduction

Evidence is lacking on second-line and later treatments for patients with RAS wild-type colorectal cancer (CRC) who receive first-line anti-epidermal growth factor receptor (EGFR) antibody therapy. In this study, we explored the real-world treatment sequences, treatment duration, and factors associated with treatment sequences and durations in Japanese patients with CRC.

Methods

This retrospective observational cohort study used a Japanese administrative claims database (April 2008 to July 2021). Patients with confirmed CRC (presumed RAS wild-type) who received first-line FOLFOX (leucovorin + 5-fluorouracil + oxaliplatin) plus anti-EGFR therapy in or after May 2016, followed by second-line irinotecan-based chemotherapy plus an antiangiogenic drug, were included. Treatment durations were estimated by the Kaplan–Meier method. Cox regression analysis was used to identify factors associated with treatment duration.

Results

Analysis populations consisted of 1163 (first-line and second-line) and 645 (third-line) patients. At the start of first-line therapy, 67.8% of patients were male, the mean age was 64 years, 83.4% had left-sided CRC, and 84.3% were prescribed FOLFOX plus panitumumab. For second-line therapy, patients were prescribed bevacizumab (63%), ramucirumab (27%), or aflibercept beta (10%). Median (95% CI) treatment durations from the start of second-line therapy to the end of antitumor drug therapies were similar for bevacizumab (12.5 months [11.2, 14.0]), ramucirumab (12.5 months [11.2, 14.8]), and aflibercept beta (14.0 months [10.4, 17.0]). Treatment duration from second-line was positively associated with first-line treatment duration of 6 months or more, CRC surgery before starting first-line therapy, and liver surgery during first-line therapy, and was negatively associated with use of nonsteroidal anti-inflammatory drugs before second-line therapy.

Conclusion

Real-world data revealed that all three antiangiogenic drugs were used as second-line therapy after first-line anti-EGFR antibodies and showed similar treatment durations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02122-4.

Plasma RAS dynamics and anti-EGFR rechallenge efficacy in patients with RAS/BRAF wild-type metastatic colorectal cancer: REMARRY and PURSUIT trials

3518

Background: Rechallenge with anti-EGFR monoclonal antibody (EGFR mAb) showed certain activities in patients (pts) with RAS/ BRAF V600E wild-type (wt) metastatic colorectal cancer (mCRC), particularly in pts with negative plasma RAS (p RAS) mutation by circulating-tumor DNA (ctDNA) assay at ‘just before’ the rechallenge therapy. However, the efficacy is unknown in pts with RAS/ BRAF wt mCRC whose p RAS was converted to positive once during or after EGFR mAb. Therefore, we conducted REMARRY, a prospective longitudinal study to investigate the p RAS dynamics, and PURSUIT trials, a phase II trial to investigate the efficacy of EGFR mAb rechallenge in pts with p RAS wt just before rechallenge therapy. Methods: The eligibility criteria of REMARRY trial included RAS/ BRAF V600E wt mCRC; ECOG PS 0-1; CR or PR during EGFR mAb; and a refractory ≤ 2 months from the last administration of EGFR mAb. p RAS status by the BEAMing method was prospectively monitored at timepoints of progression on EGFR mAb and each subsequent therapy. The eligibility criteria of PURSUIT trial included enrollment in the REMARRY trial with confirmed p RAS wt prior to enrollment in PURSUIT trial; being refractory or intolerant to fluoropyrimidine, oxaliplatin, and irinotecan; and ≥ 4 months of EGFR mAb-free interval. Study treatment was rechallenge with panitumumab + irinotecan (6 mg/kg + 150 mg/m2 q2wks). Primary endpoint was a confirmed objective response rate (ORR) according to RECIST v1.1. The required number of pts was 45, with a null ORR of 10%, an expected ORR of 25%, power of 85%, and one-sided α of 0.05. Results: Between May 2019 and May 2021, 183 pts with 343 timepoints (median, 2) were enrolled in REMARRY trial from 27 institutions, and 50 pts were enrolled in PURSUIT trial; median age, 68 years; left-sided primary, 44 pts; prior EGFR mAb, 1st/2nd/≥3rd lines was 28/6/16 pts; and p RAS status at progression on prior EGFR mAb, wt/mutant (mt)/unknown in 31/7/12 pts. Confirmed ORR and disease control rate were 14% (90% CI, 7.8%–23.9%) and 80% (95% CI, 67.0%–88.8%), respectively. In addition, 4 pts showed an unconfirmed PR. With a median follow-up time of 8.7 months, median progression-free survival was 3.6 months (95% CI, 3.0 – 4.7 months). The subgroup analysis showed a significantly higher confirmed ORR in pts with a longer EGFR mAb-free interval than a shorter one (> vs. < 365 days, 44.4% vs. 7.3%, p = 0.0037). Without any unexpected safety signals, 58.5% of pts had ≥ grade 3 adverse events. Of 31 patients with wt p RAS at progression on prior EGFR mAb, 5 had a confirmed response (ORR, 16%), whereas no response was observed in patients with 7 p RAS mt (ORR, 0%) (p = 0.25). Conclusions: The primary endpoint of confirmed ORR was not met; however, pts with p RAS wt at progression on prior EGFR mAb may benefit from rechallenge with, implying a lack of or worse response if p RAS becomes positive even once during or after EGFR mAb. Clinical trial information: REMARRY: UMIN000036424 PURSUIT: jRCTs031190096.

Effects of Metastatic Sites on Circulating Tumor DNA in Patients With Metastatic Colorectal Cancer

PURPOSE

Low concordance between plasma-based and tissue-based tests for determining the RAS mutational status have been reported in some but not all patients with limited-extent metastatic colorectal cancer (mCRC). In this study, we investigated the relationship between metastatic site and circulating tumor DNA (ctDNA) detection using ctDNA genotyping, an alternative to tissue genotyping for precision oncology.

MATERIALS AND METHODS

We investigated the relationship between metastatic site and ctDNA detection using Guardant360, a next-generation sequencing ctDNA assay, in mCRC patients with single-organ metastasis in the SCRUM-Japan GOZILA study (UMIN000029315).

RESULTS

Of 1,187 patients with mCRC enrolled in GOZILA, 138 were eligible (49 with liver-only, 15 with lymph node-only, 27 with peritoneum-only, and 47 with lung-only metastases). The concordance of RAS/BRAF status between Guaradant360 and tissue in vitro diagnostic tests was 95.9% in patients with liver-only, 80.0% in lymph node-only, 56.0% in peritoneum-only, and 65.9% in lung-only metastases. ctDNA fraction, as measured by the median maximum variant allelic fraction (max VAF), and median number of detected variants were 23.1% and five in liver-only, 6.0% and five in lymph node-only, 0.4% and three in peritoneum-only, and 0.4% and three in lung-only metastases, respectively (all P < .001, Kruskal-Wallis test). Few patients with liver-only (2.0%) and lymph node-only metastasis (13.3%) had a max VAF < 0.2%, which is required to ensure a detection limit of 95%, but max VAF was more frequently < 0.2% in patients with lung-only (27.7%) or peritoneum-only metastasis (29.6%).

CONCLUSION

Patients with lung-only and peritoneum-only metastatic disease have significantly lower levels of ctDNA, suggesting decreased clinical sensitivity for subclonal variants. This observation suggests that such patients may benefit from concurrent tissue and plasma testing to provide optimal genotyping for subsequent therapy selection.

Non-operative management after chemoradiotherapy plus consolidation or sandwich (induction with bevacizumab and consolidation) chemotherapy in patients with locally advanced rectal cancer: a multicentre, randomised phase II trial (NOMINATE trial)

INTRODUCTION

Total mesorectal excision (TME) and postoperative adjuvant chemotherapy following neoadjuvant chemoradiotherapy (CRT) is the standard treatment for locally advanced rectal cancer (LARC). However, neoadjuvant CRT has no recognised impact on reducing distant recurrence, and patients suffer from a long-lasting impairment in quality of life (QOL) associated with TME. Total neoadjuvant therapy (TNT) is an alternative approach that could reduce distant metastases and increase the proportion of patients who could safely undergo non-operative management (NOM). This study is designed to compare two TNT regimens in the context of NOM for selecting a more optimal regimen for patients with LARC.

METHODS AND ANALYSIS

NOMINATE trial is a prospective, multicentre, randomised phase II selection design study. Patients must have clinical stage II or III (T3-T4Nany) LARC with distal location (≤5 cm from the anal verge or for those who are candidates for abdominoperineal resection or intersphincteric resection). Patients will be randomised to either arm A consisting of CRT (50.4 Gy with capecitabine) followed by consolidation chemotherapy (six cycles of CapeOx), or arm B consisting of induction chemotherapy (three cycles of CapeOx plus bevacizumab) followed by CRT and consolidation chemotherapy (three cycles of CapeOx). In the case of clinical complete response (cCR) or near cCR, patients will progress to NOM. Response assessment involves a combination of digital rectal examination, endoscopy and MRI. The primary endpoint is the proportion of patients achieving pathological CR or cCR≥2 years, defined as the absence of local regrowth within 2 years after the start of NOM among eligible patients. Secondary endpoints include the cCR rate, near cCR rate, rate of NOM, overall survival, distant metastasis-free survival, locoregional failure-free survival, time to disease-related treatment failure, TME-free survival, permanent stoma-free survival, safety of the treatment, completion rate of the treatment and QOL. Allowing for a drop-out rate of 10%, 66 patients (33 per arm) from five institutions will be accrued.

ETHICS AND DISSEMINATION

The study protocol was approved by Wakayama Medical University Certified Review Board in December 2020. Trial results will be published in peer-reviewed international journals and on the jRCT website.

TRIAL REGISTRATION NUMBER

jRCTs051200121.

Clinical Validity of Plasma-Based Genotyping for Microsatellite Instability Assessment in Advanced GI Cancers: SCRUM-Japan GOZILA Substudy

PURPOSE

Circulating tumor DNA (ctDNA) genotyping may guide targeted therapy for patients with advanced GI cancers. However, no studies have validated ctDNA genotyping for microsatellite instability (MSI) assessment in comparison with a tissue-based standard.

PATIENTS AND METHODS

The performance of plasma-based MSI assessment using Guardant360, a next-generation sequencing–based ctDNA assay, was compared with that of tissue-based MSI assessment using a validated polymerase chain reaction–based method in patients with advanced GI cancers enrolled in GOZILA study, a nationwide ctDNA profiling study. The primary end points were overall percent agreement, positive percent agreement (PPA), and negative percent agreement. The efficacy of immune checkpoint inhibitor therapy was also evaluated.

RESULTS

In 658 patients with advanced GI cancers who underwent both plasma and tissue testing for MSI, the overall percent agreement, PPA, and negative percent agreement were 98.2% (95% CI, 96.8 to 99.1), 71.4% (95% CI, 47.8 to 88.7), and 99.1% (95% CI, 98.0 to 99.7), respectively. In patients whose plasma samples had a ctDNA fraction ≥ 1.0%, the PPA was 100.0% (15/15; 95% CI, 78.2 to 100.0). Three patients with MSI-high (MSI-H) tumors detected only by ctDNA genotyping achieved clinical benefits after receiving anti–programmed cell death 1 therapy with the progression-free survival ranging from 4.3 to 16.7 months. One patient with an aggressive cancer of an unknown primary site benefited from pembrolizumab after rapid detection of MSI-H by ctDNA genotyping.

CONCLUSION

ctDNA genotyping was able to detect MSI with high concordance to validated tissue-based MSI testing, especially in patients with tumors that have sufficient ctDNA shedding. Furthermore, ctDNA genotyping enabled identification of patients with MSI-H tumors who benefited from immune checkpoint inhibitor treatment.

Clinical usefulness of postoperative serum carcinoembryonic antigen in colorectal cancer patients with liver metastases

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Background: Colorectal cancer with liver metastases (CLM) has high post operative recurrence rates, and optimizing the perioperative treatment is imperative. Post operative carcinoembryonic antigen (CEA) can help detecting minimal residual disease in colon cancer after curative resection. Methods: The aim of this study was to identify the potential role of serum CEA after liver resection in patients with CLM. This study was conducted at the Cancer Institute Hospital, Japanese Foundation for Cancer Research from 2004 to 2018. Patients with CLM who underwent complete resection of primary tumors and liver metastases were enrolled in this study. We studied the associations between the perioperative CEA levels and characteristics of recurrence. Results: Recurrence was detected during the median follow-up time of 50.9 months in 343 (54.1%) of the total 633 patients analyzed. Patients with postoperative CEA (>5) group had a significantly higher recurrence rate (75.7% vs 50.0%, p < 0.01), with a shorter time until recurrence (4.4 months vs 36.9 months, p < 0.01) than those with a postoperative CEA level (≤5) group. In multivariate analysis, a postoperative CEA level >5 ng/ ml was an independent predictor, with the highest hazard ratio for both recurrence free survival (RFS) and overall survival (OS) (RFS: 2.77, 95% confidence interval [CI] 2.14–3.60, p <0.01, OS: 3.18, 95% CI 2.41–4.19, p <0.01). In addition, there was a significantly shorter RFS in the postoperative CEA level (>5) group who did not have normalized CEA levels after adjuvant chemotherapy compared to normalized CEA group (3.3 months vs 18.5 months, p = 0.008). Conclusions: The postoperative CEA and postadjuvant chemotherapy CEA level in the CEA level (>5) group after surgery may be a predictor of RFS and OS.

Real-world data analysis of antiangiogenic targeted treatments in second-line following anti-EGFR antibodies and FOLFOX in first-line for patients with metastatic colorectal cancer

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Background: Three antiangiogenic (AA) drugs, bevacizumab (BEV), ramucirumab (RAM) and aflibercept (AFL) are recommended as the second-line (2L) treatment for metastatic colorectal cancer (mCRC) in the CRC treatment guidelines of multiple countries and regions including the US, EU and Japan. However, little evidence of 2L RAM and AFL after anti-EGFR antibodies (EGFRab) in first- line (1L) has been reported. This study assessed treatment sequence for mCRC patients who received 2L irinotecan-based chemotherapy with AA drug after FOLFOX + EGFRab in 1L, treatment duration from the start of 2L to the end of last treatment line (treatment duration from 2L) and factors associated with the treatment duration from 2L. Methods: This is a real-world observational study using a hospital-based claims database of 393 hospitals in Japan. The mCRC patients who started 1L treatment with FOLFOX + EGFRab between May 2016 and Sep 2019 (identification period) and further treated with irinotecan-based chemotherapy + AA drug were enrolled. The key outcomes were the treatment sequence, treatment duration from 2L by AA drug, and factors associated with the treatment duration from 2L. Survival curves were estimated using the Kaplan–Meier method. Associated factors were investigated using Cox regression analysis. Results: Among 2,453 patients with 1L FOLFOX + EGFRab during the identification period, 506 patients who received the intended 2L therapies were enrolled in this study (mean age 63.5 years, male 66.6%). Number (%) of patients who used BEV, RAM and AFL in 2L was 345 (68.2), 120 (23.7) and 41 (8.1), respectively. Patient characteristics involving tumor location, metastatic site and prior anti-tumor therapy before starting 2L were similar among BEV, RAM and AFL. The treatment duration from 2L (median month and its 95%CI) was 11.1 (10.2-12.5) in the overall population and was similar among the patients who received BEV (10.8 [9.9-13.1]), RAM (11.2 [10.0-14.2]) and AFL (12.8 [6.9-NA]) in 2L. The treatment duration from 2L (median month and its 95%CI) for the patients who took or didn’t take proteinuria tests during 2L was 12.5 (11.1-15.2) and 8.5 (6.5-11.2), respectively. Factors positively associated with treatment duration from 2L were left-sided CRC (HR [95%CI] = 0.71 [0.53-0.96]) and ≥6 months of 1L duration (0.72 [0.56-0.93]); having renal disease (1.92 [1.28-2.88]) or received NSAIDs (1.63 [1.25-2.13]) within 60 days before starting 2L were associated negatively. Conclusions: The real-world data revealed that treatment duration were similar among BEV, RAM and AFL in 2L after EGFRab. Tumor location and 1L duration were associated with the treatment duration from 2L positively, while negative association was observed with renal disease and received NSAIDs. Treatment management was important for treatment continuation.

OUP accepted manuscript

Background

In the past decade, several successful clinical trials provided new therapeutic agents approved for advanced gastric cancer (AGC). This study evaluated whether these practice-changing results actually altered the clinical practice.

Patients and Methods

We retrospectively reviewed medical records of treatment-naive AGC patients who received combination chemotherapy of fluoropyrimidine and platinum between 2007 and 2018 and divided them into three groups: Groups A (2007-10), B (2011-14), and C (2015-2018), respectively. We compared the clinicopathological features, treatment details, and clinical outcomes among the three groups.

Results

In total, 1004 consecutive patients were enrolled (A; n = 254, B; n = 300, and C; n = 450). The number of patients with poor performance status, older age, esophagogastric junction adenocarcinoma, and primary tumor increased during the study period. All groups had similar median overall survival (OS); ~16 months) without any statistical difference but steady prolongation of survival was observed in the adjusted with imbalance prognostic factors among groups (B/A; hazard ratio, HR 0.82, 95% C.I 0.68-0.98, C/A; HR 0.72, 95% CI 0.60-0.86); OS of HER2-positive AGC patients was clearly improved (HER2-positive vs HER2-negative in Group B, HR 0.80, 95% CI 0.60-1.06; Group C, HR 0.68, 95% CI 0.51-0.90) but that of diffuse-type AGC patients remained dismal.

Conclusions

The increasing availability of chemotherapy options potentially contributed to improved survival of AGC patients, but expanded chemotherapeutic indications made the survival benefit inconspicuous in the whole population. Future therapeutic development for the AGC subset not adequately receiving benefit from previous clinical trials is warranted.

A modified MethyLight assay predicts the clinical outcomes of anti-EGFR treatment in metastatic colorectal cancer

DNA methylation status correlates with clinical outcomes of anti‐epidermal growth factor receptor (EGFR) treatment. There is a strong need to develop a simple assay for measuring DNA methylation status for the clinical application of drug selection based on it. In this study, we collected data from 186 patients with metastatic colorectal cancer (mCRC) who had previously received anti‐EGFR treatment. We modified MethyLite to develop a novel assay to classify patients as having highly methylated colorectal cancer (HMCC) or low‐methylated colorectal cancer (LMCC) based on the methylation status of 16 CpG sites of tumor‐derived genomic DNA in the development cohort (n = 30). Clinical outcomes were then compared between the HMCC and LMCC groups in the validation cohort (n = 156). The results showed that HMCC had a significantly worse response rate (4.2% vs 33.3%; P = .004), progression‐free survival (median: 2.5 vs 6.6 mo, P < .001, hazard ratio [HR] = 0.22), and overall survival (median: 5.6 vs 15.5 mo, P < .001, HR = 0.23) than did LMCC in patients with RAS wild‐type mCRC who were refractory or intolerable to oxaliplatin‐ and irinotecan‐based chemotherapy (n = 101). The DNA methylation status was an independent predictive factor and a more accurate biomarker than was the primary site of anti‐EGFR treatment. In conclusion, our novel DNA methylation measurement assay based on MethyLight was simple and useful, suggesting its implementation as a complementary diagnostic tool in a clinical setting.