Sotorasib in KRAS p.G12C-Mutated Advanced Pancreatic Cancer.

BACKGROUND: KRAS p.G12C mutation occurs in approximately 1 to 2% of pancreatic cancers. The safety and efficacy of sotorasib, a KRAS G12C inhibitor, in previously treated patients with KRAS p.G12C-mutated pancreatic cancer are unknown. METHODS: We conducted a single-group, phase 1-2 trial to assess the safety and efficacy of sotorasib treatment in patients with KRAS p.G12C-mutated pancreatic cancer who had received at least one previous systemic therapy. The primary objective of phase 1 was to assess safety and to identify the recommended dose for phase 2. In phase 2, patients received sotorasib at a dose of 960 mg orally once daily. The primary end point for phase 2 was a centrally confirmed objective response (defined as a complete or partial response). Efficacy end points were assessed in the pooled population from both phases and included objective response, duration of response, time to objective response, disease control (defined as an objective response or stable disease), progression-free survival, and overall survival. Safety was also assessed. RESULTS: The pooled population from phases 1 and 2 consisted of 38 patients, all of whom had metastatic disease at enrollment and had previously received chemotherapy. At baseline, patients had received a median of 2 lines (range, 1 to 8) of therapy previously. All 38 patients received sotorasib in the trial. A total of 8 patients had a centrally confirmed objective response (21%; 95% confidence interval [CI], 10 to 37). The median progression-free survival was 4.0 months (95% CI, 2.8 to 5.6), and the median overall survival was 6.9 months (95% CI, 5.0 to 9.1). Treatment-related adverse events of any grade were reported in 16 patients (42%); 6 patients (16%) had grade 3 adverse events. No treatment-related adverse events were fatal or led to treatment discontinuation. CONCLUSIONS: Sotorasib showed anticancer activity and had an acceptable safety profile in patients with KRAS p.G12C-mutated advanced pancreatic cancer who had received previous treatment. (Funded by Amgen and others; CodeBreaK 100 ClinicalTrials.gov number, NCT03600883.).

Microsatellite instability: A 2024 update.

Deficient mismatch repair (dMMR) results in microsatellite instability (MSI), a pronounced mutator phenotype. High-frequency MSI (MSI-H)/dMMR is gaining increasing interest as a biomarker for advanced cancer patients to determine their eligibility for immune checkpoint inhibitors (ICIs). Various methods based on next-generation sequencing (NGS) have been developed to assess the MSI status. Comprehensive genomic profiling (CGP) testing can precisely ascertain the MSI status as well as genomic alterations in a single NGS test. The MSI status can be also ascertained through the liquid biopsy-based CGP assays. MSI-H has thus been identified in various classes of tumors, resulting in a greater adoption of immunotherapy, which is hypothesized to be effective against malignancies that possess a substantial number of mutations and/or neoantigens. NGS-based studies have also characterized MSI-driven carcinogenesis, including significant rates of fusion kinases in colorectal cancers (CRCs) with MSI-H that are targets for therapeutic kinase inhibitors, particularly in MLH1-methylated CRCs with wild-type KRAS/BRAF. NTRK fusion is linked to the colorectal serrated neoplasia pathway. Recent advances in investigations of MSI-H malignancies have resulted in the development of novel diagnostic or therapeutic techniques, such as a synthetic lethal therapy that targets the Werner gene. DNA sensing in cancer cells is required for antitumor immunity induced by dMMR, opening up novel avenues and biomarkers for immunotherapy. Therefore, clinical relevance exists for analyses of MSI and MSI-H-associated genomic alterations in malignancy. In this article, we provide an update on MSI-driven carcinogenesis, with an emphasis on unique landscapes of diagnostic and immunotherapeutic strategies.

Tumor Response Predicts Survival Time of Nivolumab Monotherapy for Advanced Gastric Cancer: A Subgroup Analysis of the DELIVER Trial (JACCRO GC-08).

BACKGROUND: This prospective observational study evaluated the real-world effectiveness of nivolumab monotherapy in previously treated advanced gastric cancer (GC). A preplanned 2-year final analysis was performed to confirm survival and tumor behavior with nivolumab monotherapy. PATIENTS AND METHODS: The primary endpoint was overall survival (OS). The data regarding tumor size were prospectively collected and evaluated using the RECIST criteria. Exploratory analyses were performed for survival according to the tumor response and depth of response (DpR) in patients with measurable lesions who were receiving nivolumab monotherapy as third- or later-line therapy. RESULTS: In 487 patients, the median OS and progression-free survival (PFS) were 5.8 (95% CI 5.3-6.9) months and 1.8 (95% CI 1.7-2.0) months, respectively. The response rate (RR) was 14.5% in 282 patients with measurable lesions. In 234 patients treated with third- or later-line, the DpR was found to be associated with PFS and OS in the Spearman analysis (r = 0.55 and 0.44, respectively) as well as using a discrete variable. When the DpR was divided into 5 groups (-20%≥DpR; -20%

An approach for improvement of the accuracy of cancer gene panel testing.

BACKGROUND: Tissue-based comprehensive genomic profiling (CGP) is increasingly being employed for genotype-directed therapies in patients with advanced cancer. However, tissue availability may limit their potential applications. In Japan, the cost of cancer gene panel tests is covered by public insurance for patients diagnosed with advanced solid tumors once in their lifetime. Therefore, it is essential to improve the success rate (reportability) and accuracy of CGP tests. The purpose of this study was to identify the factors associated with efficient and accurate CGP testing using relevant information obtained from real-world data. METHODS: This study included 159 samples analyzed using tumor-only panel FoundationOne® CDx cancer genome profiling (F1CDx) and 85 samples analyzed using matched-pair panel OncoGuide™ NCC Oncopanel system (NCCOP) at St. Marianna University Hospital. Sample characteristics (fixation conditions, storage period, histology, tumor cell ratio, and genomic tumor cell content), CGP performance, and quality control status were evaluated across all 244 tested samples. RESULTS: In 237/244 samples (97.1%), CGP testing results were successfully obtained [F1CDx, 99.4% (158/159) and NCCOP, 92.9% (79/85)]. An increased number of fibroblasts, inflammatory cells, and necrotic tumor cells, long-term storage, and/or prolonged fixation of tissue sections were involved in the unreported results and/or qualified CGP results. In addition, a negative correlation between median insert size values and ΔΔCq was observed in the NCCOP system. CONCLUSION: We identified various factors associated with efficient and accurate CGP testing using relevant information obtained from real-world data, suggesting that thorough selection and preparation of tissue sections could optimize CGP and maximize useful information.

Second-line tislelizumab versus chemotherapy in Japanese patients with advanced or metastatic esophageal squamous cell carcinoma: subgroup analysis from RATIONALE-302.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) has a poor prognosis, with limited second-line systemic therapy options, and represents an increasing disease burden in Japan. In the phase 3 RATIONALE-302 study, the anti-programmed cell death protein 1 antibody, tislelizumab, significantly improved overall survival (OS) versus chemotherapy as second-line treatment for advanced/metastatic ESCC. Here, we report the Japanese patient subgroup results. METHODS: Patients with advanced/metastatic ESCC, with disease progression during/after first-line systemic therapy were randomized 1:1 to open-label tislelizumab 200 mg every 3 weeks or investigator's choice of chemotherapy (paclitaxel/docetaxel). Efficacy and safety were assessed in all randomized Japanese patients. RESULTS: The Japanese subgroup comprised 50 patients (n = 25 per arm). Tislelizumab improved OS versus chemotherapy (median: 9.8 vs. 7.6 months; HR 0.59; 95% CI 0.31, 1.12). Among patients with programmed death-ligand 1 score ≥ 10%, median OS was 12.5 months with tislelizumab (n = 10) versus 2.9 months with chemotherapy (n = 6) (HR 0.31; 95% CI 0.09, 1.03). Tislelizumab improved progression-free survival versus chemotherapy (median: 3.6 vs. 1.7 months, respectively; HR 0.50; 95% CI 0.27, 0.95). Objective response rate was greater with tislelizumab (32.0%) versus chemotherapy (20.0%), and responses were more durable (median duration of response: 8.8 vs. 2.6 months, respectively). Fewer patients experienced ≥ grade 3 treatment-related adverse events with tislelizumab (24.0%) versus chemotherapy (47.8%). Tislelizumab demonstrated an improvement in health-related quality of life versus chemotherapy. CONCLUSIONS: As second-line therapy for advanced/metastatic ESCC, tislelizumab improved OS versus chemotherapy, with a favorable safety profile, in the Japanese patient subgroup, consistent with the overall population. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov: NCT03430843.

Trifluridine/tipiracil+bevacizumab (BEV) vs. fluoropyrimidine-irinotecan+BEV as second-line therapy for metastatic colorectal cancer: a randomised noninferiority trial.

BACKGROUND: This open-label, multicentre, phase II/III trial assessed the noninferiority of trifluridine/tipiracil (FTD/TPI) plus bevacizumab vs. fluoropyrimidine and irinotecan plus bevacizumab (control) as second-line treatment for metastatic colorectal cancer (mCRC). METHODS: Patients were randomised (1:1) to receive FTD/TPI (35 mg/m2 twice daily, days 1-5 and days 8-12, 28-day cycle) plus bevacizumab (5 mg/kg, days 1 and 15) or control. The primary endpoint was overall survival (OS). The noninferiority margin of the hazard ratio (HR) was set to 1.33. RESULTS: Overall, 397 patients were enrolled. Baseline characteristics were similar between the groups. Median OS was 14.8 vs. 18.1 months (FTD/TPI plus bevacizumab vs. control; HR 1.38; 95% confidence interval [CI] 0.99-1.93; Pnoninferiority = 0.5920). In patients with a baseline sum of the diameter of target lesions of <60 mm (n = 216, post hoc analyses), the adjusted median OS was similar between groups (FTD/TPI plus bevacizumab vs. control, 21.4 vs. 20.7 months; HR 0.92; 95% CI 0.55-1.55). Grade ≥3 adverse events (FTD/TPI plus bevacizumab vs. control) included neutropenia (65.8% vs. 41.6%) and diarrhoea (1.5% vs. 7.1%). CONCLUSIONS: FTD/TPI plus bevacizumab did not demonstrate noninferiority to fluoropyrimidine and irinotecan plus bevacizumab as second-line treatment for mCRC. CLINICAL TRIAL REGISTRATION: JapicCTI-173618, jRCTs031180122.

Clinical significance of circulating-tumour DNA analysis by metastatic sites in pancreatic cancer.

BACKGROUND: Liquid biopsy is an alternative to tissue specimens for tumour genotyping. However, the frequency of genomic alterations with low circulating-tumour DNA (ctDNA) shedding is shown in pancreatic ductal adenocarcinoma (PDAC). We, therefore, investigated the prevalence of KRAS mutations and ctDNA fraction by the metastatic site in patients with PDAC. METHODS: This study enrolled previously treated PDAC patients from a plasma genomic profiling study; ctDNA analysis was performed using Guardant360 at disease progression before initiating subsequent treatment. RESULTS: In 512 patients with PDAC, KRAS mutations were detected in 57%. The frequency of KRAS mutation in ctDNA differed depending on the metastatic organ; among patients with single-organ metastasis (n = 296), KRAS mutation detection rate was significantly higher in patients with metastasis to the liver (78%). In addition, the median maximum variant allele frequency (VAF) was higher with metastasis to the liver (1.9%) than with metastasis to the lungs, lymph nodes, peritoneum or with locally advanced disease (0.2%, 0.4%, 0.2% and 0.3%, respectively). CONCLUSION: The prevalence of KRAS mutations and maximum VAF were higher in patients with metastasis to the liver than in those with metastasis to other sites. This study indicated the clinical utility of ctDNA analysis, especially in PDAC with liver metastases.

Addition of docetaxel to S-1 results in significantly superior 5-year survival outcomes in Stage III gastric cancer: a final report of the JACCRO GC-07 study.

PURPOSE: A phase III trial comparing S-1 and docetaxel with S-1 alone as postoperative chemotherapy for pathologically Stage III gastric cancer was conducted and clarified the superiority of the doublet in terms of 3-year relapse-free survival as the primary endpoint (67.7% versus 57.4%, hazard ratio [HR] 0.715, 95% confidence interval [CI] 0.587-0.871; p = 0.0008). This final report analyzed 5-year survival outcomes along with the incidence and pattern of late recurrences. PATIENTS AND METHODS: Patients with histologically confirmed Stage III gastric cancer who underwent gastrectomy with D2 lymphadenectomy were randomly assigned to receive adjuvant chemotherapy with either S-1 plus docetaxel or S-1 alone. The same 912 patients who were evaluated for 3-year survival outcomes in the previous report were analyzed. RESULTS: Five-year overall survival rate of the S-1 plus docetaxel group (67.91%) was significantly superior to that in the S-1 group (60.27%; HR 0.752, 95% CI 0.613-0.922; p = 0.0059). The incidence of late recurrence at > 3 years after randomization was similar in both groups (7.3% versus 7.2%). Peritoneal dissemination was the most common pattern of late recurrence. Addition of docetaxel significantly suppressed relapse through the lymphatic (6.8% [95% CI 4.52-9.17] versus 15% [95% CI 11.76-18.30]; p < 0.0001) and hematogenous (10.2% [95% CI 7.37-12.94] versus 15.7% [95% CI 12.36-19.01]; p < 0.0137) pathways throughout the 5 years of follow-up. CONCLUSION: The survival benefit of postoperative chemotherapy with S-1 and docetaxel in terms of 5-year overall survival rate was confirmed for patients with pathologically Stage III gastric cancer, although late recurrences were not prevented.

The BEETS (JACCRO CC-18) trial: an observational and translational study of BRAF-mutated metastatic colorectal cancer.

For BRAF V600E-mutated metastatic colorectal cancer (mCRC), the BEACON phase 3 trial showed survival benefit of triplet therapy with cetuximab (anti-EGFR antibody), encorafenib (BRAF inhibitor) and binimetinib (MEK inhibitor) as well as doublet therapy with cetuximab and encorafenib over irinotecan-based chemotherapy plus anti-EGFR antibody. Both regimens are standards of care in Japan, but definite biomarkers for predicting efficacy and selecting treatment remain lacking. The mechanisms underlying resistance to these regimens also warrant urgent exploration to further evolve treatment. This prospective observational/translational study evaluated real-word clinical outcomes with cetuximab and encorafenib with or without binimetinib for BRAF-mutated mCRC patients and investigated biomarkers for response and resistance by collecting blood samples before and after treatment. Clinical Trial Registration: UMIN000045530 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000051983).

The BEETS trial is a study that looks at how well two combinations of targeted therapies (cetuximab + encorafenib with or without binimetinib) work and how safe they are for patients with advanced colorectal cancer that has a mutation (change) in the BRAF gene. In this trial, patients participate voluntarily instead of being assigned to one of the two therapy groups. When a patient has BRAF-mutated advanced colorectal cancer, it means that the cancer cells in their body have changes in a gene called BRAF. This gene normally produces a protein called BRAF, which is involved in the growth of cells. However, when there is a mutation in this gene, it can cause the production of an overactive BRAF protein, leading to fast and excessive cell growth and division. For patients with BRAF-mutated advanced colorectal cancer, combinations of targeted therapies have been found to be effective as a second- or third-line treatment, based on the results of a phase 3 clinical trial. The main goal of the BEETS trial is to evaluate how well these treatments work and how safe they are when used in real-world clinical practice. Additionally, the study will use laboratory tests (liquid biopsy) to explore new biomarkers that can help predict how well a treatment will work and assist in selecting the most suitable treatment plans. We hope that the findings of this study will contribute to improving the overall management of this specific type of cancer.

Comprehensive review of undifferentiated carcinoma of the pancreas: from epidemiology to treatment.

Undifferentiated carcinoma (UC) of the pancreas is a rare subtype of pancreatic cancer displaying no definitive direction of differentiation. UC has been reported as a highly aggressive malignant neoplasm, with a median overall survival of <1 year, except for several surgical series. On the other hand, UC tissue sometimes contains non-neoplastic osteoclast-like giant cells (OGCs), and such cases have been reported to have relatively longer survival. Thus, the World Health Organization (WHO) classification histologically distinguishes UC with OGCs (UCOGCs) from UC, and UCs were subclassified into three subtypes: anaplastic UC, sarcomatoid UC and carcinosarcoma. However, still less is known about UC due to its rarity, and such situations lead to further difficulties in treatment for UC. To date, only surgical resection can offer curative treatment for patients with UC, and no clear evidence for chemotherapy exists for them. However, a retrospective cohort study and case reports showed that relatively promising results paclitaxel-containing regimens for treatment of patients with unresectable UC. Furthermore, high programmed cell death protein 1 expression has been reported in sarcomatoid UCs and UCOGCs, and promising responses to anti-programmed death-ligand 1 therapy have been described in case reports of UCOGCs. Recent advances in chemotherapeutic agents and molecular technologies are opening up the possibilities for expanded treatments.

Phase I study of aflibercept in combination with docetaxel in Japanese patients with advanced solid malignancies.

Angiogenesis is a hallmark of cancer development. This study sought to determine the recommended dose of aflibercept, a recombinant fusion protein targeting VEGF-A, VEGF-B and placental growth factor (PlGF), combined with docetaxel in Japanese patients with advanced solid malignancies. This phase I study was planned to include 12 patients following a 3 + 3 algorithm to determine the maximum tolerated dose of aflibercept combined with docetaxel in patients with metastatic or unresectable solid tumors (trial registration: NCT00545246). Docetaxel (75 mg/m2 every 3 weeks or 60 mg/m2 after protocol amendment) was combined with escalating doses of aflibercept (2, 4 and 6 mg/kg every 4 weeks). Free and VEGF-bound aflibercept were measured to assess free aflibercept in excess of the VEGF-bound form. At the starting dose of the combination, 3 of 6 patients treated experienced febrile neutropenia. After reducing the docetaxel dose to 60 mg/m2 in step 2 and permitting therapeutic granulocyte colony-stimulating factor (G-CSF) use, 2 of 3 patients in both cohorts experienced febrile neutropenia. Five patients (42%) had a partial response and 4 patients had stable disease (33%). Free aflibercept in excess of the VEGF-bound form was not maintained at this dose level. The dose limiting toxicity (DLT) of aflibercept combined with docetaxel was febrile neutropenia, which occurred in 2 of 3 Japanese patients at the lowest aflibercept dose level (2 mg/kg) combined with docetaxel (60 mg/m2) and therapeutic G-CSF use. A recommended dose for further studies was not determined because of the DLT at the starting dose.

Phase I study of envafolimab (KN035), a novel subcutaneous single-domain anti-PD-L1 monoclonal antibody, in Japanese patients with advanced solid tumors.

Envafolimab is the first and only globally approved subcutaneously injectable PD-L1 antibody. This open-label, multicenter Phase 1 trial assessed the safety, tolerability, pharmacokinetic (PK) profile, and efficacy of envafolimab as a single agent in Japanese patients with advanced solid tumors. In the dose-escalation phase, 10 patients received subcutaneous (SC) envafolimab QW at 1.0 mg/kg, 2.5 mg/kg and 5.0 mg/kg. In the dose-expansion phase, 16 patients were treated at 2.5 or 5.0 mg/kg Q2W in part-1 and 9 patients received SC envafolimab 300 mg Q4W in part-2. No dose-limiting toxicities (DLTs) were reported. Envafolimab was well tolerated and no new safety signals were identified compared with other marketed products of the same class. Three patients reported Grade ≥ 3 envafolimab-related treatment-emergent adverse events (TEAE), including adrenal insufficiency, cerebral infarction, and immune-mediated enterocolitis. Envafolimab demonstrated dose-proportional increases in area under the time-concentration curve (AUC) and maximum serum concentration (Cmax). The overall response rate (ORR) was 11.4% (n = 4) and disease control rate (DCR) was 34.3% (n = 12). Consistent with that observed in other envafolimab Phase 1 trials and approved PD-1/PD-L1 inhibitors, the safety profile of SC envafolimab in Japanese patients with advanced solid tumors was well tolerated with efficacy comparable to IV administered treatments. Pharmacokinetics data and preliminary anti-tumor response support dose regimens with longer dosing intervals (Q2W or Q4W). As such, envafolimab offers patients a more convenient treatment option than currently available intravenously administered PD-1/PD-L1 inhibitors. CLINICALTRIALS.GOV IDENTIFIER: NCT03248843(August 14, 2017).

Feasibility of edoxaban for asymptomatic cancer-associated thrombosis in Japanese patients with gastrointestinal cancer: ExCAVE study.

BACKGROUND: Although initial therapy with a parenteral anticoagulant is required before edoxaban, this strategy is frequently avoided in actual clinical practice because of its complexity. This study assessed the feasibility of edoxaban without initial heparin usage for asymptomatic cancer-associated thrombosis (CAT) in Japanese patients with gastrointestinal cancer (GIC) at high risk of bleeding. METHODS: In this multicenter prospective feasibility study conducted at 10 Japanese institutions, patients with active GIC who developed accidental asymptomatic CAT during chemotherapy were recruited. Edoxaban was orally administered once daily without initial parenteral anticoagulant therapy within 3 days after detecting asymptomatic CAT. The primary outcome was the incidence of major bleeding (MB) or clinically relevant non-major bleeding (CRNMB) during the first 3 months of edoxaban administration. RESULTS: Of the 54 patients enrolled from October 2017 to September 2020, one was excluded because of a misdiagnosis of CAT. In the remaining 53 patients, the primary outcome occurred in six patients (11.3%). MB occurred in four patients (7.5%), including gastrointestinal bleeding in three patients and intracranial hemorrhage in one patient. CRNMB occurred in two patients (3.8%), including bleeding from the stoma site and genital bleeding in one patient each. There were no deaths attributable to bleeding, and all patients who experienced MB or CRNMB recovered. CONCLUSIONS: The risk of bleeding after edoxaban without heparin pretreatment was acceptable, demonstrating new treatment options for asymptomatic CAT in patients with GIC.

Impact of Body Weight Loss on Survival in Patients with Advanced Gastric Cancer Receiving Second-Line Treatment.

Limited information is available regarding the impact of body weight loss (BWL) in patients with advanced gastric cancer (AGC) who receive second-line chemotherapy. We retrospectively reviewed data for consecutive AGC patients who received second-line treatment with taxane-based chemotherapy at our institution between January 2014 and September 2018. We calculated variables, including percent BWL per month during chemotherapy (%BWL/m), and analyzed the correlations between BWL and other clinicopathological parameters with survival. Forty-four AGC patients were registered (median age, 67.5 years; females, n = 16 [36.3%]; severe ascites, n = 12 [27.3%]). The median overall survival was significantly shorter among patients with a %BWL/m of 1% or more, compared with patients with less weight loss (6.3 mo, vs. 12.3 mo, P = 0.038). The %BWL/m (≥1% vs. <1%) was significantly correlated with survival in a univariate analysis (HR = 2.11, P = 0.04), and the survival period was shorter for patients with severe ascites (HR = 1.92; 95% CI, 0.90-3.90) and if their %BWL/m was 1% or more (HR = 2.01; 95% CI, 0.98-4.10) in a multivariate analysis. In conclusion, BWL during second-line chemotherapy was associated with a poor prognosis among patients with AGC.

Real-world effectiveness of nivolumab in advanced gastric cancer: the DELIVER trial (JACCRO GC-08).

BACKGROUND: There is no large real-world data regarding efficacy and safety of immunotherapy in gastric cancer (GC). Although some tumors can grow rapidly after immunotherapy, the patient proportions and survival outcomes are unclear in GC. METHODS: A multicenter, prospective observational study was performed to evaluate clinical outcomes including survival time, safety, and tumor behavior of nivolumab treatment for patients with advanced GC. Primary endpoint was overall survival (OS), and secondary endpoints included response rate (RR), disease control rate (DCR), progression-free survival (PFS), tumor growth rate (TGR) at first evaluation, and safety. RESULTS: Of 501 enrolled patients, 487 were evaluable (median age 70 years, 71% male, performance status 0/1/2 [42%/44%/14%], 21% HER2-pos, 42% patients with ascites). Median OS was 5.82 months (95% CI 5.29-7.00) with a 1-year survival rate of 30% and median PFS of 1.84 months (95% CI 1.71-1.97). The DCR was 39.4% and the RR was 14.2% (95% CI 10.3-18.8) in 282 patients with measurable lesions. In 219 patients evaluable for TGR, 20.5% were identified as hyperprogressive disease (HPD). OS from the first evaluation of patients with HPD was shorter compared with non-HPD (HR 1.77, 95% CI 1.25-2.51, P = 0.001), but it was not worse than that of patients with progression and non-HPD (HR 1.05, 95% CI 0.72-1.53, P = 0.8). A multivariate analysis revealed the presence of peritoneal metastasis was a prognostic factor for OS and PFS. CONCLUSIONS: Our real-world data demonstrated the comparable survival time to a previous clinical trial and revealed the frequency and prognosis of patients with HPD in advanced GC treated with nivolumab.

REMARRY and PURSUIT trials: liquid biopsy-guided rechallenge with anti-epidermal growth factor receptor (EGFR) therapy with panitumumab plus irinotecan for patients with plasma RAS wild-type metastatic colorectal cancer.

BACKGROUND: Previous clinical trials have demonstrated the potential efficacy of rechallenge with anti- epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) for patients with RAS/BRAF V600E wild-type metastatic colorectal cancer (mCRC). Moreover, post hoc biomarker analyses of clinical trials has suggested that RAS status in circulating tumor DNA (ctDNA) has a high probability to select patients who could benefit from anti-EGFR mAb rechallenge. METHODS: This trial is composed of 2 phases: a monitoring phase (REMARRY) and a trial phase (PURSUIT). A monitoring phase, the REMARRY study, aims to evaluate the dynamics of plasma RAS status during the subsequent treatments after refractory to anti-EGFR therapy in patients with mCRC with RAS/BRAF V600E wild-type tumors who have progressed after a response to previous anti-EGFR therapy, using a highly sensitive digital polymerase chain reaction OncoBEAM RAS CRC kit in a central laboratory (Sysmex, Japan). A trial phase, the PURSUIT trial, is a multicenter, single-arm phase II trial to assess the efficacy and safety of rechallenge therapy with panitumumab plus irinotecan in patients without RAS mutations in ctDNA (plasma RAS negative) in the REMARRY study. Key eligibility criteria of the PURSUIT trial include RAS/BRAF V600E wild-type mCRC in tumor tissue refractory or intolerant to fluoropyrimidine, oxaliplatin, and irinotecan; progression after complete or partial response to previous anti-EGFR therapy; plasma RAS negative (defined as plasma mutant allele frequencies [MAF] of all RAS ≤ 0.1%) within 28 days prior to enrollment; 4 months or more between the last administration of previous anti-EGFR mAb and the start of protocol treatment; and Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) ≤ 1. The primary endpoint is the confirmed objective response rate (ORR). The target sample size of the PURSUIT trial is 50 patients. Biomarker analyses will be performed in parallel using the OncoBEAM RAS CRC kit and a next-generation sequencing-based ctDNA analysis (Guardant360). DISCUSSION: Our trial aims to confirm the clinical benefit of anti-EGFR mAb rechallenge therapy in patients with plasma RAS negative. Moreover, through biomarker analyses, our trial will shed light on which patients would benefit from rechallenge in addition to being plasma RAS negative. TRIAL REGISTRATION: The REMARRY study: UMIN, UMIN000036424 . Registered date: April 5, 2019. The PURSUIT trial: jRCT, jRCTs031190096 . Registered date: October 1, 2019.

REVIVE study: a prospective observational study in chemotherapy after nivolumab therapy for advanced gastric cancer.

Nivolumab is an increasingly used standard care treatment for heavily pretreated patients with advanced gastric cancer, with increasing clinical use in Japan. Data from retrospective studies on various tumors have shown the objective response rate to cytotoxic chemotherapy potentially improves after an exposure to immune checkpoint inhibitors. Based on these data, we conducted the multicenter observational REVIVE study to evaluate the efficacy and safety of cytotoxic chemotherapy in nivolumab-refractory or nivolumab-intolerant patients with advanced gastric cancer. Patients who are refractory or intolerant to nivolumab and scheduled to receive irinotecan monotherapy, oxaliplatin combination treatment or oral trifluridine/tipiracil hydrochloride therapy will be included. The primary end point is overall survival of nivolumab-pretreated patients with advanced gastric cancer after the cytotoxic chemotherapy. Clinical trial registration: UMIN000032182 (umin.ac.jp).

Japanese Society of Medical Oncology Clinical Guidelines: Molecular Testing for Colorectal Cancer Treatment, 4th edition.

Molecular testing to select the appropriate targeted and standard of care therapies is essential for managing patients with colorectal cancer (CRC). The Japanese Society of Medical Oncology previously published clinical guidelines for molecular testing in CRC. In the third edition published in 2018, RAS and BRAF V600E mutations should be tested prior to first-line chemotherapy to assess the benefit of anti-epidermal growth factor receptor (EGFR) antibody therapy in patients with unresectable CRC. Microsatellite instability (MSI) testing was recommended in patients with curatively resected stage II CRC because deficient mismatch repair is associated with low risk of recurrence. MSI testing was also recommended in patients with CRC suspected to be Lynch syndrome. The main aim of this fourth edition is to reflect recent advances in comprehensive genomic profiling (CGP) tests and liquid biopsy. Here, CGP tests performed on tumor tissues are strongly recommended to assess the benefit of molecular targeted drugs in patients with CRC. Circulating tumor DNA (ctDNA)-based CGP tests are also proposed. ctDNA testing is recommended to determine the optimal treatment based on the risk of recurrence for curatively resected CRC and evaluate the suitability and monitor the therapeutic effects of anti-EGFR antibodies in patients with unresectable CRC. While both MSI testing and immunohistochemistry are strongly recommended to determine the indication of immune checkpoint inhibitors in patients with unresectable CRC, next-generation sequencing-based tests are weakly recommended because these tests have not been validated in clinical trials.

Phase I study of the anti-heparin-binding epidermal growth factor-like growth factor antibody U3-1565 with cetuximab in patients with cetuximab- or panitumumab-resistant metastatic colorectal cancer.

KRAS wild-type colorectal cancers initially responsive to anti-endothelial growth factor receptor (EGFR) antibodies [cetuximab (Cetu)/panitumumab (Pani)] develop acquired resistance. Overexpression of EGFR ligands such as heparin-binding EGF-like growth factor (HB-EGF) may be one resistance mechanism. This phase I study of U3-1565, anti-HB-EGF antibody, and Cetu combination therapy enrolled patients with KRAS wild-type metastatic colorectal cancer who had received two ≤ regimens with fluoropyrimidine, oxaliplatin, irinotecan, and Cetu/Pani and had disease progression on Cetu/Pani. Recommended dose (RD) was determined in the 1st stage, followed by evaluation of efficacy at the RD level in the 2nd-stage. Cetu was given at a loading dose of 400 mg/m2 followed by weekly infusions of 250 mg/m2 in levels 1 and 0. U3-1565 was administered at a loading dose of 24 mg/m2 followed by biweekly infusions of 16 mg/m2 in level 1 and 16-12 mg/m2 in level 0. Twenty-two patients were enrolled. No dose-limiting toxicities were observed among three patients in level 1 in the first stage, which was determined as RD. Grade 3 or higher adverse events occurred in 59.1%; those in ≥5% of patients were anemia, γ-GTP elevation, and acneiform rash. Overall response rate was 0.0% [95% confidence interval (CI): 0.0%-15.4%] and disease control was achieved in 17 patients (77.3%, 95% CI: 54.6%-92.2%). Median progression-free survival time was 85.0 days (95% CI: 54.0-91.0) and median survival time was 196 days (95% CI: 113.0-306.0). RD was determined as level 1. The efficacy of this combination therapy after progression on Cetu/Pani was negligible. Trial Registration: UMIN000013006.

Analysis of fistula formation of T4 esophageal cancer patients treated by chemoradiotherapy.

BACKGROUND AND AIM: Fistula is one of the known complications of T4 esophageal cancer (T4-EC). The standard treatment for T4-EC is chemoradiotherapy, but detailed data about fistula resulting from chemoradiotherapy in this condition are limited. In particular, radiographic findings of T4-EC with fistula have not been reported. This study assessed the risk factors of fistula based on clinical information on patients with chemoradiotherapy for T4-EC. METHODS: We retrospectively reviewed the clinical data of 59 T4-EC patients who had squamous cell carcinoma without any fistula before receiving definitive or palliative chemoradiotherapy. RESULTS: A fistula was observed in 18 patients (31%) throughout their clinical course. The overall survival in the fistula group was significantly shorter than that in the non-fistula group (259 vs. 346 days; p = 0.0341). The axial tumor size on computed tomography (CT) was confirmed as an independent risk factor for esophageal fistula in multivariate analysis of stepwise methods [OR 1.226; 95% CI 1.109-1.411; p < 0.0001]. Twelve out of 14 patients with an axial tumor size of 50 mm or greater had developed a fistula. CONCLUSIONS: A large tumor size on the axial plane on CT is a risk factor for fistula formation.