'ESMO ASIA' kicks off…focus on Asian patient data

Scheduled to be held in Singapore for 3 days from Dec 5…subanalysis data on Asian population will be unveiled

Multiple success in gastric cancer…confirmed effectiveness of Imfinzi adjuvant therapy·Keytruda combination

For Leclaza combination, median OS has not been achieved…Success of ADC, such as Datroway and Enhertu

Asian patient data of global new drugs, including Immune checkpoint inhibitors, targeted anticancer agents, and antibody-drug conjugates (ADC), will be primarily unveiled. 

The European Society for Medical Oncology Asia (ESMO ASIA 2025) annual meeting, held over three days starting December 5 in Singapore, will feature post-hoc analysis targeting Asian populations from major pharmaceutical companies, including AstraZeneca (AZ), MSD, and Janssen. As Asia became a central hub for global clinical trials, not just a participating region, data of Asian patients, including Koreans, has emerged as the key focus of this year's conference.

AZ's immune checkpoint inhibitor Imfinzi stands out in gastric cancer…ADC results continue

The company set to gain spotlight at the conference is AstraZeneca. AstraZeneca will unveil results of its new drugs, including the immune checkpoint inhibitor 'Imfinzi (durvalumab)', ADC anticancer agent 'Datroway (datopotamab)', and 'Enhertu (trastuzumab deruxtecan)'.

Imfinzi confirmed its potential as a perioperative adjuvant therapy in gastric cancer through the Phase 3 MATTERHORN study.

The final analysis of the MATTERHORN Phase 3 trial, presented at ESMO 2025 in Berlin in October, confirmed that Imfinzi given as a perioperative therapy statistically significantly improved Overall Survival (OS). At ESMO Asia 2025, clinical results for 180 Asian patients, including Koreans, will be presented.

This study is evaluated as the first to demonstrate that an immuno-oncology agent provides a survival benefit as a perioperative adjuvant therapy for gastric cancer. The trial design targeted resectable locally advanced gastric (Stage 2–4A) and gastroesophageal junction (GEJ) adenocarcinoma patients, administering Imfinzi + FLOT (fluorouracil, leucovorin, oxaliplatin, docetaxel) pre-surgery, followed by Imfinzi maintenance post-surgery.

AstraZeneca continues to deliver strong results in the antibody-drug conjugate (ADC) field. First, the TROP2-targeting Datroway confirmed its potential as a first-line treatment for Triple-Negative Breast Cancer (TNBC). The Phase 3 TROPION-Breast02 study evaluated the efficacy and safety of Datroway compared with standard chemotherapy.

The study confirmed that Datroway monotherapy improved both OS and Progression-Free Survival (PFS) compared to the control group.

Previously, patients with PD-L1-negative TNBC have had no therapeutic options other than chemotherapy. Datroway is expected to be a major player in metastatic TNBC soon. Professor Sung-bae Kim (Oncology, Asan Medical Center) is scheduled to present the clinical results at ESMO Asia 2025.

Enhertu also confirmed again its potential as a first-line treatment for HER2-positive metastatic breast cancer through the Phase 3 DESTINY-Breast09 study.

Enhertu was previously used in the second-line setting, but combining it with Roche's targeted agent Perjeta (pertuzumab) suggests the possibility of moving the treatment to the first line. Perjeta is one of the drugs used in the standard-of-care 'THP' (taxane-containing agent + Herceptin + Perjeta) for first-line HER2-positive breast cancer.

The study compared the efficacy and safety of Enhertu + Perjeta versus the THP in 1,157 previously untreated HER2-positive breast cancer patients. Patients were randomized 1:1:1 to Enhertu + placebo (387 patients), Enhertu + Perjeta (383 patients), or the THP (387 patients).

The primary endpoint was PFS, assessed using blinded independent central review (BICR). Other endpoints included OS, Objective Response Rate (ORR), Duration of Response (DOR), and safety. The trial showed statistically significant improvements in PFS and ORR with Enhertu compared to the control group.

Results from targeted agents·immune checkpoint inhibitors…consistent effects on Korean patients

Another key research result to be introduced at this conference is the Phase 3 MARIPOSA study. The OS subgroup analysis focusing on Asian patients for Janssen's NSCLC treatments, 'Rybrevant (amivantamab)' and 'Leclaza (lazertinib)', will be revealed.

Leclaza, developed by Yuhan, is a third-generation Tyrosine Kinase Inhibitor (TKI) targeting EGFR Exon 19 deletion and Exon 21 (L858R) mutations. Johnson & Johnson holds the global rights to Leclaza. The company has been conducting clinical research to evaluate the efficacy of its combination with Rybrevant, a targeted option against Exon 20 and MET mutations.

In this trial, the Rybrevant + Leclaza arm showed a statistically significant improvement in survival compared to the 'Tagrisso (osimertinib)' monotherapy group (p < 0.005).

The results show that the median OS for the Rybrevant + Leclaza group was not estimable (42.9-NE), compared to 36.7 months for the Tagrisso monotherapy group. Based on the survival curve distribution, the Rybrevant + Leclaza arm is expected to extend OS by at least 12 months compared with the Tagrisso arm. These results were recently published in the New England Journal of Medicine (NEJM), drawing significant attention from the academic community.

In the clinical results, the median OS for the combination arm was not confirmed, while Tagrisso monotherapy was 36.7 months. Thus, the Leclaza combination is expected to provide an OS extension benefit of at least 12 months compared to Tagrisso. The subgroup analysis, which included 501 Asian patients, showed efficacy consistent with the overall analysis. 

MSD will also unveil significant long-term follow-up data on gastric cancer. The data to be presented is a subgroup analysis of Asian patients from the Phase 3 KEYNOTE-859 study, including long-term results from a wide range of Asian patients across Korea, China, Japan, Taiwan, Malaysia, and Singapore.

The Keytruda + chemotherapy combination is already established as the standard of care for first-line treatment of HER2-negative advanced gastric/gastroesophageal junction (G/GEJ) adenocarcinoma, demonstrating improvements in OS·PFS·ORR. This analysis reports the 52.4 months long-term follow-up results for Asian patients. 

According to the study, the Keytruda combination therapy continued to show a superior trend compared to placebo across all endpoints in Asian patients. This subgroup analysis, which includes a large number of Korean patients, is viewed as data that reaffirms the standard of care status of the 'Keytruda + chemotherapy' combination for first-line HER2-negative gastric cancer.