Kensei Yamaguchi

Dr. Kensei Yamaguchi

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 June 2024 in Journal of Clinical Oncology
Verified
Journal Article
Open access
YJYelena Y. Janjigian
Yelena Y. Janjigian
Jaffer AjaniJaffer Ajani
Jaffer Ajani
MMMarkus Moehler
Markus Moehler
SLShen Lin
Shen Lin
MGMarcelo Garrido
Marcelo Garrido
KSKohei Shitara
Kohei Shitara
Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. We report 3-year efficacy and safety results from the phase III CheckMate 649 trial. Patients with previously untreated advanced or metastatic gastroesophageal adenocarcinoma were randomly assigned to nivolumab plus chemotherapy or chemotherapy. Primary end points were overall survival (OS) and progression-free survival (PFS) by blinded independent central review (BICR) in patients whose tumors expressed PD-L1 combined positive score (CPS) ≥5. With 36.2-month minimum follow-up, for patients with PD-L1 CPS ≥5, the OS hazard ratio (HR) for nivolumab plus chemotherapy versus chemotherapy was 0.70 (95% CI, 0.61 to 0.81); 21% versus 10% of patients were alive at 36 months, respectively; the PFS HR was 0.70 (95% CI, 0.60 to 0.81); 36-month PFS rates were 13% versus 8%, respectively. The objective response rate (ORR) per BICR was 60% (95% CI, 55 to 65) with nivolumab plus chemotherapy versus 45% (95% CI, 40 to 50) with chemotherapy; median duration of response was 9.6 months (95% CI, 8.2 to 12.4) versus 7.0 months (95% CI, 5.6 to 7.9), respectively. Nivolumab plus chemotherapy also continued to show improvement in OS, PFS, and ORR versus chemotherapy in the overall population. Adding nivolumab to chemotherapy maintained clinically meaningful long-term survival benefit versus chemotherapy alone, with an acceptable safety profile, supporting the continued use of nivolumab plus chemotherapy as standard first-line treatment for advanced gastroesophageal adenocarcinoma.

1 February 2023 in Journal of Clinical Oncology
Verified
Journal Article
Open access
KYKensei Yamaguchi
Kensei Yamaguchi
Yung-Jue BangYung-Jue Bang
Yung-Jue Bang
Satoru IwasaSatoru Iwasa
Satoru Iwasa
NSNaotoshi Sugimoto
Naotoshi Sugimoto
MRMin-Hee Ryu
Min-Hee Ryu
KSKohei Shitara
Kohei Shitara
PURPOSE: To investigate efficacy and safety of trastuzumab deruxtecan (T-DXd) in human epidermal growth factor receptor 2 (HER2)–low gastric or gastroesophageal junction (GEJ) adenocarcinoma. METHODS: Patients with locally advanced or metastatic HER2-low (cohort 1, immunohistochemistry 2+/in situ hybridization–negative; cohort 2, immunohistochemistry 1+) gastric/GEJ adenocarcinoma treated with at least two prior regimens, including fluoropyrimidine and platinum, but anti-HER2 therapy naive, received T-DXd 6.4 mg/kg intravenously once every 3 weeks. The primary end point was confirmed objective response rate by independent central review. RESULTS: Among 21 patients enrolled in cohort 1 and 24 enrolled in cohort 2, 19 and 21 patients, respectively, had central HER2 confirmation, received T-DXd, and had measurable tumors at baseline. The confirmed objective response rate was 26.3% (95% CI, 9.1 to 51.2) from five partial responses in cohort 1 and 9.5% (95% CI, 1.2 to 30.4) from two partial responses in cohort 2. Thirteen patients (68.4%) in cohort 1 and 12 (60.0%) in cohort 2 experienced reduced tumor size. The median overall survival was 7.8 months (95% CI, 4.7 to nonevaluable) in cohort 1 and 8.5 months (95% CI, 4.3 to 10.9) in cohort 2; the median progression-free survival was 4.4 months (95% CI, 2.7 to 7.1) and 2.8 months (95% CI, 1.5 to 4.3), respectively. The most common grade ≥ 3 treatment-emergent adverse events in cohorts 1 and 2 were anemia (30.0% and 29.2%), decreased neutrophil count (25.0% and 29.2%), and decreased appetite (20.0% and 20.8%). Drug-related interstitial lung disease/pneumonitis occurred in one patient in each cohort (grade 1 or 2). No drug-related deaths occurred. CONCLUSION: This study provides preliminary evidence that T-DXd has clinical activity in patients with heavily pretreated HER2-low gastric/GEJ adenocarcinoma.

28 January 2021 in Journal of the Anus, Rectum and Colon
Verified
Journal Article
Open access
PDF file
AOAkira Ooki
Akira Ooki
ESEiji Shinozaki
Eiji Shinozaki
KYKensei Yamaguchi
Kensei Yamaguchi
Despite the recent advances in the systemic treatment of metastatic colorectal cancer (mCRC), prognostic outcomes have remained to be poor. Thus, what is needed is an innovative treatment approach. Immune checkpoint inhibitors (ICIs) targeting programmed death-1 (PD-1) and anti-programmed cell death ligand 1 (PD-L1) have exhibited a durable response and dominated the treatment of various tumor types. However, in mCRC, the clinical benefit is limited in patients with deficient mismatch repair (dMMR) /high levels of microsatellite instability (MSI-H), comprising approximately 5% of mCRC cases, and some do not respond to ICI treatment. Thus, further research is needed to identify predictive biomarkers. The most urgent need is developing effective immunotherapy for patients with proficient mismatch repair (pMMR) /microsatellite stable (MSS) cancer, which comprises 95% of mCRC cases. Tumors with the pMMR/MSS phenotype often exhibit a lower tumor mutation burden and fewer tumor-infiltrating lymphocytes than dMMR/MSI-H, leading to immune tolerance and evasion in the tumor microenvironment. Therefore, a number of investigative studies aimed at overcoming tumor resistance in current immunotherapy approaches are underway. A better understanding on the complexity and diversity of the immune system's functioning within the tumor microenvironment will increase the potential for developing predictive biomarkers and novel therapeutic strategies to potentiate anti-tumor immunity in patients with mCRC. In this review, we summarize the most recent advances in immunotherapy based on the findings of pivotal clinical trials for patients with mCRC, highlighting potent therapeutic approaches and predictive biomarkers.

4 November 2025 in International Journal of Clinical Oncology
Verified
Journal Article
Open access
PDF file
YKYusuke Kinugasa
Yusuke Kinugasa
KUKay Uehara
Kay Uehara
KYKensei Yamaguchi
Kensei Yamaguchi
YSYutaka Saito
Yutaka Saito
KMKeiko Murofushi
Keiko Murofushi
JRJapanese Society For Cancer Of The Colon And Rectum
Japanese Society For Cancer Of The Colon And Rectum
The number of deaths from colorectal cancer in Japan continues to rise, with over 50,000 deaths recorded in 2018. In the 2024 edition, revisions to all aspects of treatment were undertaken, with corrections and additions made based on knowledge gained since the 2022 version (drug therapy) and the 2019 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2024 for the treatment of colorectal cancer have been prepared to present standard treatment strategies, reduce disparities among institutions, avoid both unnecessary and insufficient treatment, and enhance mutual understanding between healthcare professionals and patients by making these guidelines accessible to the public. These guidelines were developed through consensus by the JSCCR Guideline Committee, following a careful review of evidence retrieved from literature searches and considering the medical insurance system and actual clinical practice in Japan. Therefore, these guidelines serve as a tool for managing colorectal cancer in real-world clinical settings. More specifically, they can be used to support obtaining informed consent from patients and selecting the most appropriate treatment method for each patient. Controversial topics were selected as clinical questions, and recommendations were provided. Each recommendation is accompanied by an evidence classification and a recommendation category, both based on consensus reached by the Guideline Committee members. This article presents the English version of the JSCCR guidelines 2024.

1 February 2018 in European Journal of Cancer
Verified
Journal Article
Open access
ECEric Van Cutsem
Eric Van Cutsem
RMRobert J. Mayer
Robert J. Mayer
SLStéphanie Laurent
Stéphanie Laurent
RWRobert Winkler
Robert Winkler
CGCristina Grávalos
Cristina Grávalos
AOAtsushi Ohtsu
Atsushi Ohtsu
In the phase III RECOURSE trial, trifluridine/tipiracil (TAS-102) extended overall survival (OS) and progression-free survival (PFS) with an acceptable toxicity profile in patients with metastatic colorectal cancer refractory or intolerant to standard therapies. The present analysis investigated the efficacy and safety of trifluridine/tipiracil in RECOURSE subgroups. Primary and key secondary end-points were evaluated using a Cox proportional hazards model in prespecified subgroups, including geographical subregion (United States of America [USA], European Union [EU], Japan), age (<65 years, ≥65 years) and v-Ki-ras2 Kirsten rat sarcoma 2 viral oncogene homologue (KRAS) status (wild type, mutant). Safety and tolerability were reported with descriptive statistics. Eight-hundred patients were enrolled: USA, n = 99; EU, n = 403; Japan, n = 266. Patients aged ≥65 years and those with mutant KRAS tumours comprised 44% and 51% of all patients in the subregions, respectively. Final OS analysis (including 89% of events, compared with 72% in the initial analysis) confirmed the survival benefit associated with trifluridine/tipiracil, with a hazard ratio (HR) of 0.69 (95% confidence interval [CI] 0.59-0.81; P = 0.0001). Median OS in the three regions was 6.5-7.8 months in the trifluridine/tipiracil arm and 4.3-6.7 months in the placebo arm (USA: HR 0.56; 95% CI 0.34-0.94; P = 0.0277; EU: HR 0.62; 95% CI 0.48-0.80; P = 0.0002; Japan: HR 0.75; 95% CI 0.57-1.00; P = 0.0470). Median PFS was 2.0-2.8 months for trifluridine/tipiracil and 1.7-1.8 months for placebo; HRs favoured trifluridine/tipiracil in all regions. Similar clinical benefits of trifluridine/tipiracil were observed in elderly patients and in those with mutant KRAS tumours. There were no marked differences among subregions in terms of safety and tolerability. Trifluridine/tipiracil was effective in all subgroups, regardless of age, geographical origin or KRAS status. This trial is registered with ClinicalTrials.gov: NCT01607957.

14 January 2021 in Clinical Cancer Research
Verified
Journal Article
Open access
PDF file
ZWZev A. Wainberg
Zev A. Wainberg
CFCharles S. Fuchs
Charles S. Fuchs
Josep TaberneroJosep Tabernero
Josep Tabernero
KSKohei Shitara
Kohei Shitara
KMKei Muro
Kei Muro
JCJoseph Chao
Joseph Chao
Purpose: Pembrolizumab demonstrated efficacy in PD-L1–positive [combined positive score (CPS) ≥1] advanced gastric/gastroesophageal junction (G/GEJ) cancer in the first-, second-, and third-line setting in KEYNOTE-062, KEYNOTE-061, and KEYNOTE-059, respectively. To better delineate the specificity of CPS as a predictor of clinical outcomes, we analyzed pembrolizumab efficacy in patients with CPS ≥ 10 in these trials. Patients and Methods: Included were patients with CPS ≥ 10 tumors from KEYNOTE-059 cohort 1 (pembrolizumab, n = 46; post hoc), KEYNOTE-061 (pembrolizumab, n = 53; chemotherapy, n = 55; post hoc), and KEYNOTE-062 (pembrolizumab, n = 92; chemotherapy, n = 90; primary). Efficacy outcomes were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR). Results: In KEYNOTE-059, median follow-up was 6 months, median OS was 8 months [95% confidence interval (CI), 5.8–11.1], ORR was 17%, and median (range) DOR was 21 months (3+ to 35+). In KEYNOTE-061, median follow-up was 9 months, median OS (pembrolizumab vs. chemotherapy) was 10 versus 8 months (HR, 0.64; 95% CI, 0.41–1.02), median PFS was 3 months versus 3 months (HR, 0.86; 95% CI, 0.56–1.33), ORR was 25% versus 9%, and median (range) DOR was not reached (4 to 26+ months) versus 7 months (3–7). In KEYNOTE-062, median follow-up was 11 months, median OS (pembrolizumab vs. chemotherapy) was 17 months versus 11 months (HR, 0.69; 95% CI, 0.49–0.97), median PFS was 3 months versus 6 months (HR, 1.09, 95% CI; 0.79–1.49), ORR was 25% versus 38%, and median (range) DOR was 19 months (1+ to 34+) versus 7 months (2+ to 30+). Conclusions: This comprehensive analysis showed consistent improvements toward more favorable clinical outcomes with pembrolizumab across lines of therapy in patients with CPS ≥ 10 G/GEJ cancer.