The goal of this clinical trial is to assess the safety and efficacy of ANO31905 in combination with chemotherapy as the first-line treatment for subjects with CLDN18.2-positive locally advanced unresectable or metastatic pancreatic cancer.

Inclusion Criteria:

1. Males or females aged ≥ 18 at the time of signing the ICF;
2. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
3. Expected survival ≥ 3 months;
4. Histologically or cytologically confirmed diagnosis of pancreatic ductal adenocarcinoma;
5. At least one measurable lesion according to RECIST v1.1;
6. Tumor tissue samples are determined to be CLDN18.2-positive by immunohistochemistry (IHC) in the central laboratory;
7. Patients with sufficient organ function within 7 days before the first study dose;
8. Non-pregnant or -lactating women.

Exclusion Criteria:

1. Patients with other malignant tumors except pancreatic adenocarcinoma within 5 years before the first dose of the study treatment; Any previous systematic anti-cancer therapy
2. Any previous systematic anti-cancer therapy;
3. Previous treatment targeting CLDN18.2;
4. Patients with a history of active autoimmune disorders or autoimmune disorders requiring systemic treatment;
5. Patients with known hypersensitivity to any component or excipient of ANO31905, gemcitabine, and nanoparticle albumin-bound paclitaxel;
6. Patients with known metastases to the central nervous system;
7. Patients with severe cardiovascular and cardiovascular diseases;
8. Presence risks of thrombosis or bleeding;
9. Patients who have received attenuated live vaccines within 28 days before the first study dose or are expected to receive attenuated live vaccines during study treatment;
10. Patients with gastrointestinal diseases that are not suitable for enrollment as judged by the investigator;
11. Patients with other conditions that may place the patients at increased undue study-related risks.