Abstract 131P
Background
PD-1 inhibitors plus chemotherapy was approved as standard 1L treatment for advanced HER2-negative G/GEJA, but its outcomes remain poor in patients (pts) with low PD-L1 expression. For advanced HER2-positive G/GEJA, integrating immunotherapy with trastuzumab and chemotherapy has shown a significant improvement in progression-free survival (PFS) and overall survival (OS). Cadonilimab, a PD-1/CTLA-4 bispecific antibody, has demonstrated its efficacy and safety in previously untreated advanced G/GEJA pts, even those with PD-L1 CPS<5 in a phase III study. Currently, cadonilimab plus XELOX as 1L treatment for advanced G/GEJA was approved by NMPA. This phase II trial was to assess the efficacy and safety of cadonilimab with or without trastuzumab in combination with SOX in advanced G/GEJA.
Methods
Untreated G/GEJA pts received cadonilimab+SOX (HER2-negative pts) or cadonilimab+trastuzumab+ SOX (HER2-positive pts) for up to 6 cycles, followed by maintenance with S-1+cadonilimab with (HER2-positive pts) or without trastuzumab (HER2-negative pts) until disease progression or intolerable toxicities. The primary endpoint was objective response rate (ORR), and secondary endpoints were disease control rate (DCR), PFS, OS, and safety.
Results
As of September 24, 2024, 19 pts were enrolled, of which 13 (68.4%) were HER2 negative and 6 (31.6%) were HER2 positive. The median age was 62.0 (range: 21-74) and 8 (42.1%) were PD-L1 CPS<5 and HER2 negative. One pt had no post-baseline tumor assessment in HER2-negative pts. Among HER2-positive pts, 6 reached PR, the ORR and DCR were both 100.0%. Of the HER2-negative pts, 6 were PR and 6 exhibited SD, the ORR was 50.0% (6/12) and DCR was 100.0% (12/12). Among HER2-negative pts with PD-L1 CPS<1, the ORR was 57.1% (4/7) and DCR was 100.0% (7/7). Median PFS and OS were not mature. 3 pts (15.0%) developed grade 3 treatment-related adverse events (TRAEs). There were no grade 4/5 TRAEs.
Conclusions
Cadonilimab with or without trastuzumab in combination with SOX showed promising efficacy and tolerable safety as 1L treatment in HER2-positive or HER2-negative advanced G/GEJA, particularly a high ORR in HER2-positive group.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
7P - ACOX2 disturbs the stability of MRE11-RAD50-NBS1 complex and shapes activated immune tumor microenvironment in clear cell renal cell carcinoma
Presenter: Shiqi Ye
Session: Poster Display session
Resources:
Abstract
9P - CXCR6+PD-1- Tissue Resident memory T cells are associated with poor prognosis in patients with metastatic colorectal cancer
Presenter: Emilien Laloy
Session: Poster Display session
Resources:
Abstract
10P - Tumor-infiltrating lymphocytes and tertiary lymphoid structures in oral cavity squamous cell carcinoma in non-smokers and non-drinkers: Predict clinical outcome
Presenter: Israa Laklouk
Session: Poster Display session
Resources:
Abstract
11P - Tumor-infiltrating lymphocytes on routine H&E staining with automated quantification predict outcomes in resectable non-small cell lung cancer
Presenter: Guus Heuvel
Session: Poster Display session
Resources:
Abstract
12P - Epithelial-mesenchymal transition facilitates response to AXL/PD-1 inhibition in relapsed mesothelioma
Presenter: Essa Baitei
Session: Poster Display session
Resources:
Abstract
14P - Integrated genomic analysis of whole genomes to derive a biomarker of durable response to immunotherapy in melanoma
Presenter: Irene Lobon
Session: Poster Display session
Resources:
Abstract
15P - Verteporfin might potentiate the effects of anti-PD-1 therapy in melanoma-bearing mice model
Presenter: Szonja Kovács
Session: Poster Display session
Resources:
Abstract
16P - Immune checkpoint blockade and HLA-related epistasis in melanoma: Genetic determinants of response and toxicity
Presenter: Martin Little
Session: Poster Display session
Resources:
Abstract
17P - Identification PD-L1-associated lncRNA biomarkers for immunoregulation in ovarian cancer
Presenter: Hee Jung Kim
Session: Poster Display session
Resources:
Abstract
19P - Genetic profiling of early triple-negative breast cancer patients with an indication for neoadjuvant pembrolizumab
Presenter: Bogdan Popescu
Session: Poster Display session
Resources:
Abstract