114P - Cadonilimab plus chemotherapy as first-line (1L) treatment for metastatic gastric (G) or gastroesophageal junction adenocarcinoma (GEJA) with PD-L1 CPS=5: Updated results from a real-world study

Background

PD-1 inhibitors plus chemotherapy have been the standard 1L treatment for metastatic G/GEJA, but its efficacy remain poor in patients (pts) with low PD-L1 expression. A phase III study has demonstrated that cadonilimab, a PD-1/CTLA-4 bispecific antibody, showed encouraging activity and manageable safety in previously untreated pts with metastatic G/GEJA, even those with PD-L1 CPS<5. Currently, cadonilimab combined with XELOX as 1L treatment for metastatic G/GEJA was approved by NMPA. Here, we presented the updated efficacy and safety of the combination for metastatic G/GEJA with PD-L1 CPS≤5 in a real-world setting.

Methods

Untreated pts with metastatic G/GEJA and PD-L1 CPS≤5 who has received cadonilimab combined with chemotherapy (SOX, XELOX or FOLFOX) were included in this real-world study. Baseline characteristics, treatment patterns, and clinical outcomes, including objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and treatment-related adverse events (TRAEs) were analyzed.

Results

As of August 24, 2024, 31 pts were enrolled. At baseline, median age was 56.0 years (range: 25-75), 67.7% were ECOG PS 1/2 and 48.4% were PD-L1 CPS＜1. 4 pts underwent surgical treatment under the guidance of MDT, including 3 with PD-L1 CPS＜1. All pts were evaluable for safety and efficacy. 17 reached PR and 14 were SD. Overall ORR was 54.8% and DCR was 100.0%. Median PFS (mPFS) was 7.38 months (mo) (95% Cl: 5.55-9.21) and median OS (mOS) was 14.26 mo (95% Cl: 11.08-17.44). In the PD-L1 CPS＜1 group, the ORR was 53.3% (8/15) and DCR was 100.0% (15/15), mPFS was 9.25 mo (95% Cl: 0.00-20.09) and mOS was 14.26 mo (95% Cl: 7.78-20.74). Pts with liver metastasis (25.8%, 8/31) had a higher ORR (8 PR, 100%) compared to the overall ORR (54.8%). TRAEs were observed in 67.7% pts, including 9.7% grade 3 TRAEs (neutropenia 6.5%, thrombocytopenia 3.2% and diabetes 3.2%). There were no grade 4/5 toxicities.

Conclusions

Cadonilimab plus chemotherapy continued to show a promising efficacy with manageable safety in the 1L treatment of metastatic G/GEJA pts with PD-L1 CPS≤5, particularly a high ORR in pts with liver metastasis.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.