Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer (GC), published in late 2022 and the updated ESMO Gastric Cancer Living Guideline published in July 2023, were adapted in August 2023, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with GC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with GC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), coordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian regions represented by the 10 oncological societies. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with GC across the different regions of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation. Attention is drawn to the disparity in the drug approvals and reimbursement strategies, between the different regions of Asia.

Comprehensive clinical and molecular characterization of claudin 18.2 expression in advanced gastric or gastroesophageal junction cancer

BACKGROUND

We conducted comprehensive clinical and molecular characterization of claudin 18.2 expression (CLDN18.2) in advanced gastric or gastroesophageal junction cancer (GC/GEJC).

PATIENTS AND METHODS

Patients with advanced GC/GEJC who received systemic chemotherapy from October 2015 to December 2019 with available tumor specimens were analyzed. We evaluated clinicopathological features of CLDN18.2 expression with four molecular subtypes: mismatch repair deficient, Epstein-Barr virus-positive, human epidermal growth factor receptor 2-positive, and others. In addition, programmed death-ligand 1 (PD-L1) combined positive score (CPS), genomic alterations, and the expression of immune cell markers were assessed. Clinical outcomes of standard first- or second-line chemotherapy and subsequent anti-programmed cell death protein 1 (anti-PD-1) therapy were also investigated according to CLDN18.2 expression.

RESULTS

Among 408 patients, CLDN18.2-positive (moderate-to-strong expression in ≥75%) was identified in 98 patients (24.0%) with almost equal distribution in the four molecular subtypes or CPS subgroups. CLDN18.2-positive was associated with Borrmann type 4, KRAS amplification, low CD16, and high CD68 expression. Overall survival with first-line chemotherapy was not significantly different between CLDN18.2-positive and -negative groups [median 18.4 versus 20.1 months; hazard ratio 1.26 (95% confidence interval 0.89-1.78); P = 0.191] regardless of stratification by PD-L1 CPS ≥5. Progression-free survival and objective response rates of first- and second-line chemotherapy, and anti-PD-1 therapy also showed no significant differences according to CLDN18.2 status.

CONCLUSIONS

CLDN18.2 expression in advanced GC/GEJC was associated with some clinical and molecular features but had no impact on treatment outcomes with chemotherapy or checkpoint inhibition. CLDN18.2-positive also had no impact on overall survival. This information could be useful to interpret the results from currently ongoing clinical trials of CLDN18.2-targeted therapies for advanced GC/GEJC and to consider a treatment strategy for CLDN18.2-positive GC/GEJC.

Pooled safety analysis from phase III studies of trifluridine/tipiracil in patients with metastatic gastric or gastroesophageal junction cancer and metastatic colorectal cancer

BACKGROUND

Trifluridine/tipiracil (FTD/TPI) showed clinical benefit, including improved survival and manageable safety in previously treated patients with metastatic colorectal (mCRC) or gastric/gastroesophageal junction (mGC/GEJC) cancer in the phase III RECOURSE and TAGS trials, respectively. A pooled analysis was conducted to further characterize FTD/TPI safety, including management of haematologic toxicities and use in patients with renal or hepatic impairment.

PATIENTS AND METHODS

Adults with ≥2 prior regimens for advanced mGC/GEJC or mCRC were randomized (2 : 1) to FTD/TPI [35 mg/m² twice daily days 1-5 and 8-12 (28-day cycle); same dosage in both trials] or placebo plus best supportive care. Adverse events (AEs) were summarized in the safety population (patients who received ≥1 dose) and analysed by renal/hepatic function.

RESULTS

TAGS and RECOURSE included 335 and 533 FTD/TPI-treated and 168 and 265 placebo-treated patients, respectively. Overall safety of FTD/TPI was similar in TAGS and RECOURSE. Haematologic (neutropenia, anaemia) and gastrointestinal (nausea, diarrhoea) AEs were most commonly observed. Laboratory-assessed grade 3-4 neutropenia occurred in 37% (TAGS)/38% (RECOURSE) of FTD/TPI-treated patients (median onset: 29 days/55 days), and 96% (TAGS)/97% (RECOURSE) of cases resolved regardless of renal/hepatic function. Supportive medications for neutropenia were received by 17% (TAGS) and 9% (RECOURSE); febrile neutropenia was reported in 2% and 4%, respectively. Overall grade ≥3 AEs were more frequent in patients with moderate renal impairment [81% (TAGS); 85% (RECOURSE)] versus normal renal function (74%; 67%); anaemia and neutropenia were more common in patients with renal impairment. FTD/TPI safety (including haematologic AEs) was consistent across patients with normal and mildly impaired hepatic function.

CONCLUSIONS

These results support FTD/TPI as a well-tolerated treatment in patients with mGC/GEJC or mCRC, with a consistent safety profile. Safety was largely similar in patients with normal or mildly impaired renal/hepatic function; however, patients with renal impairment should be monitored for haematologic toxicities.

Quality of life with first-line pembrolizumab for PD-L1-positive advanced gastric/gastroesophageal junction adenocarcinoma: results from the randomised phase III KEYNOTE-062 study

BACKGROUND

In the randomised phase III KEYNOTE-062 study, pembrolizumab was non-inferior to chemotherapy for overall survival in patients with programmed death-ligand 1 (PD-L1)-positive [combined positive score (CPS) ≥1] advanced gastric/gastroesophageal junction (GEJ) cancer. We present findings of prespecified health-related quality-of-life (HRQOL) analyses for pembrolizumab versus chemotherapy in this population.

MATERIALS AND METHODS

HRQOL, a secondary endpoint, was measured in patients who received ≥1 dose of study treatment and completed ≥1 HRQOL questionnaire [European Organisation for the Research and Treatment of Cancer (EORTC) 30-question quality-of-life (QLQ-C30), EORTC 22-question quality-of-life gastric-cancer-specific module (QLQ-STO22)]. Least squares mean (LSM) change (baseline to week 18) in global health status/quality of life (GHS/QOL; EORTC QLQ-C30) and time to deterioration (TTD) in GHS/QOL, nausea/vomiting and appetite loss scores (EORTC QLQ-C30) and abdominal pain/discomfort scores (EORTC QLQ-STO22) were evaluated.

RESULTS

The HRQOL population comprised 495 patients with CPS ≥1 (pembrolizumab, 252; chemotherapy, 243). Compliance rates at week 18 were similar for pembrolizumab and chemotherapy (EORTC QLQ-C30, 87.9% and 81.9%; EORTC QLQ-STO22, 87.9% and 81.3%, respectively). There was no between-arm difference in LSM score change in GHS/QOL [-0.16; 95% confidence interval (CI) -5.01 to 4.69; P = 0.948]. The LSM score change for most subscales showed comparable worsening in both arms. TTD for GHS/QOL [hazard ratio (HR), 0.96; 95% CI, 0.67-1.38; P = 0.826], appetite loss (HR, 0.83; 95% CI, 0.58-1.20; P = 0.314) and pain (HR, 1.22; 95% CI, 0.78-1.91; P = 0.381) were similar between arms. Longer TTD was observed for pembrolizumab versus chemotherapy for nausea/vomiting (HR, 0.61; 95% CI, 0.44-0.85; P = 0.003).

CONCLUSIONS

HRQOL was maintained with first-line treatment with pembrolizumab in patients with PD-L1-positive advanced gastric/GEJ cancer and was similar between pembrolizumab and chemotherapy in this population.

Trifluridine/tipiracil versus placebo for third or later lines of treatment in metastatic gastric cancer: an exploratory subgroup analysis from the TAGS study

BACKGROUND

Metastatic gastric cancer and cancer of the esophagogastric junction (GC/EGJ) is an aggressive disease with poor prognosis. In the TAGS study, trifluridine/tipiracil (FTD/TPI) improved overall survival (OS) compared with placebo in heavily pre-treated patients. This unplanned, exploratory subgroup analysis of the TAGS study aimed to clarify outcomes when FTD/TPI was used as third-line (3L) treatment and fourth- or later-line (4L+) treatment.

PATIENTS AND METHODS

Patients were divided into a 3L group (126 and 64 in FTD/TPI and placebo arms, respectively) and 4L+ group (211 and 106 in FTD/TPI and placebo arms, respectively). Endpoints included OS, progression-free survival (PFS), time to Eastern Cooperative Oncology Group performance status (ECOG PS) deterioration to ≥2, and safety.

RESULTS

Baseline characteristics were generally well balanced between FTD/TPI and placebo for 3L and 4L+ treatment. Median OS (mOS) for FTD/TPI versus placebo was: 6.8 versus 3.2 months {hazard ratio (HR) [95% confidence interval (CI)] = 0.68 (0.47-0.97), P = 0.0318} in the 3L group; and 5.2 versus 3.7 months [0.73 (0.55-0.95), P = 0.0192] in the 4L+ group. Median PFS for FTD/TPI versus placebo was 3.1 versus 1.9 months [0.54 (0.38-0.77), P = 0.0004] in the 3L group; and 1.9 versus 1.8 months [0.57 (0.44-0.74), P < 0.0001] in the 4L+ group. Time to deterioration of ECOG PS to ≥2 for FTD/TPI versus placebo was 4.8 versus 2.0 months [HR (95% CI) = 0.60 (0.42-0.86), P = 0.0049] in the 3L group; and 4.0 versus 2.5 months [0.75 (0.57-0.98), P = 0.0329] in the 4L+ group. The safety of FTD/TPI was consistent in all subgroups.

CONCLUSIONS

This analysis confirms the efficacy and safety of FTD/TPI in patients with GC/EGJ in third and later lines with a survival benefit that seems slightly superior in 3L treatment. When FTD/TPI is taken in 3L as recommended in the international guidelines, physicians can expect to provide patients with an mOS of 6.8 months.

Molecular determinants of clinical outcomes with pembrolizumab versus paclitaxel in a randomized, open-label, phase III trial in patients with gastroesophageal adenocarcinoma

BACKGROUND

In the phase III KEYNOTE-061 trial (NCT02370498), pembrolizumab did not significantly improve overall survival versus paclitaxel as second-line therapy for gastric/gastroesophageal junction (GEJ) adenocarcinoma with programmed death-ligand 1 (PD-L1) combined positive score (CPS) ≥1 tumors. The association of tissue tumor mutational burden (tTMB) status and clinical outcomes was determined, including the relationship with CPS and microsatellite instability-high (MSI-H) status.

PATIENTS AND METHODS

In patients with whole exome sequencing (WES) data [420/592 (71%); pembrolizumab, 218; paclitaxel, 202], the association of tTMB with objective response rate (ORR; logistic regression), progression-free survival (PFS; Cox proportional hazards regression), and overall survival (OS; Cox proportional hazards regression) were measured using one-sided (pembrolizumab) and two-sided [paclitaxel] P values. tTMB was also evaluated using FoundationOne®CDx [205/592 (35%)]. Prespecified equivalent cut-offs of 175 mut/exome for WES and 10 mut/Mb for FoundationOne®CDx were used.

RESULTS

WES-tTMB was significantly associated with ORR, PFS, and OS in pembrolizumab-treated (all P < 0.001) but not paclitaxel-treated patients (all P > 0.6) in univariate analysis. The area under the receiver operating characteristics curve for WES-tTMB and response was 0.68 [95% confidence interval (CI) 0.56-0.81] for pembrolizumab and 0.51 (95% CI 0.39-0.63) for paclitaxel in univariate analysis. There was low correlation between WES-tTMB and CPS in both treatment groups (r ≤ 0.16). WES-tTMB remained significantly associated with all clinical endpoints with pembrolizumab after adjusting for CPS and with PFS and OS after excluding known MSI-H tumors (n = 26). FoundationOne®CDx-tTMB demonstrated a positive association with ORR, PFS, and OS in pembrolizumab-treated patients (all P ≤ 0.003) but not PFS or OS in paclitaxel-treated patients (P > 0.1).

CONCLUSION

This exploratory analysis from KEYNOTE-061 is the first to demonstrate a strong association between tTMB and efficacy with pembrolizumab but not paclitaxel in patients with gastric/GEJ adenocarcinoma in a randomized setting. Data further suggest tTMB is a significant and independent predictor beyond PD-L1 status.

Oxaliplatin-based adjuvant chemotherapy duration (3 versus 6 months) for high-risk stage II colon cancer: the randomized phase III ACHIEVE-2 trial

BACKGROUND

Oxaliplatin-based adjuvant chemotherapy may be associated with debilitating peripheral sensory neuropathy (PSN) in patients with high-risk stage II colon cancer. This open-label, multicenter, randomized phase III trial was conducted as a prospective pooled analysis to investigate the non-inferiority of 3 versus 6 months of adjuvant oxaliplatin-based chemotherapy.

PATIENTS AND METHODS

From 12 February 2014 to 31 January 2017, 525 Asian patients with high-risk stage II colon cancer were randomly assigned to 3- and 6-month treatment arms. The treatment consisted of either modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or capecitabine combined with oxaliplatin (CAPOX). The primary end point was disease-free survival (DFS). The secondary end points were treatment compliance and safety.

RESULTS

Of the 525 randomized patients, 11 were not treated. Among the 514 participating patients (255 in the 3-month arm; 259 in the 6-month arm), 432 (84%) received CAPOX, and 184 (36%) presented with T4 as a high-risk factor for recurrence. The 3-year DFS rate was 88.2% in the 3-month arm and 87.9% in the 6-month arm [hazard ratio (HR), 1.12; 95% confidence interval (CI), 0.67-1.87]. With CAPOX, the 3-year DFS rate was 88.2% in the 3-month arm and 88.4% in the 6-month arm (HR, 1.13; 95% CI, 0.65-1.96). The discontinuation rate in the 3- and 6-month arms was 10% and 31% for mFOLFOX6 (P = 0.0193), and 15% and 35% for CAPOX (P < 0.0001), respectively. The incidence of grade ≥2 PSN was significantly lower in the 3-month arm than in the 6-month arm (16% and 43%, respectively, P < 0.0001).

CONCLUSIONS

Three months of combination therapy presented significantly less grade ≥2 PSN than the respective 6-month regimen. The shortened therapy duration did not affect the 3-year DFS rate, suggesting that a 3-month course of CAPOX can be an effective treatment option.

CLINICAL TRIAL INFORMATION

UMIN Clinical Trials Registry, UMIN000013036 and Japan Registry of Clinical Trials, jRCTs031180128.