Inclusion Criteria:
* Subjects must voluntarily participate in the study and sign the informed consent form.
* Aged between 18 and 75 years (inclusive) at the time of signing the informed consent form.
* Diagnosed with pancreatic ductal adenocarcinoma through histological or cytological confirmation.
* Have at least one evaluable metastatic lesion according to RECIST 1.1 criteria;
* No prior systemic anti-tumor therapy (including but not limited to chemotherapy, radiotherapy, targeted therapy, or immunotherapy). Patients who experience disease progression more than 6 months after completing neoadjuvant or adjuvant therapy are eligible.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, with an expected survival of more than 3 months.
* Normal major organ function.
* Patients must use reliable contraception during the study period and for 6 months after the end of the study period; Female participants must have a negative serum or urine pregnancy test within 7 days prior to enrollment and must not be breastfeeding.
Exclusion Criteria:
* Subjects with a history of or concurrent diagnosis of other malignant tumors within the past 5 years.
* Unresolved toxicities from prior treatments exceeding Grade 1 according to Common Terminology Criteria (CTC) AE criteria, excluding alopecia.
* Major surgical procedures, significant traumatic injuries, or unhealed wounds or fractures within 28 days prior to the first dose.
* Any bleeding or hemorrhagic event of ≥ Grade 3 according to CTC AE criteria within 4 weeks prior to the first dose.
* Arterial or venous thrombotic events within 6 months prior to the first dose.
* Active gastric or duodenal ulcers, perforations, persistent positive fecal occult blood tests, ulcerative colitis, or other gastrointestinal bleeding conditions within 6 months prior to the first dose; or other bleeding conditions as assessed by the investigator.
* Hepatitis B virus (HBV)-infected patients unable to adhere to consistent antiviral therapy, or Hepatitis C virus (HCV)-infected patients (positive for HCV Ab or HCV RNA) deemed unstable by the investigator or requiring continued antiviral therapy without consistent adherence.
* History of substance abuse involving psychotropic drugs that cannot be discontinued or presence of psychiatric disorders.
* Symptomatic interstitial lung disease or conditions likely to cause drug-induced lung toxicity or related pneumonitis.
* Presence of any severe and/or uncontrolled diseases.
* Histological or cytological confirmation of other pathological types, such as acinar cell carcinoma, neuroendocrine carcinoma, or pancreatoblastoma.
* Tumors confirmed via imaging (CT or MRI) to have invaded major blood vessels, with the investigator deeming a high likelihood of fatal hemorrhage during the study.
* Tumors confirmed via imaging (CT or MRI) to have invaded the gastrointestinal tract, with a high risk of bleeding based on endoscopy and investigator assessment.
* Known central nervous system metastases and/or carcinomatous meningitis.
* Uncontrolled pleural effusion, pericardial effusion, or ascites requiring repeated drainage, as assessed by the investigator.
* History of severe allergic reactions to biologic agents or known hypersensitivity to any component of TQB2868 injection.
* Chronic treatment with systemic corticosteroids or other immunosuppressive agents within 28 days prior to the first dose, and continued use of such medications within 2 weeks after the first dose.
* Receipt of live attenuated vaccines within 28 days prior to the first dose or planned administration of live attenuated vaccines during the study.
* Systemic therapy required within 2 years prior to the first dose for any condition. Alternative therapies are not considered systemic therapy.
* Participation in other clinical trials involving anti-tumor drugs within 28 days prior to the first dose.
* Any comorbidities or conditions deemed by the investigator to pose severe risks to the subject's safety or the completion of the study, or any other reasons rendering the subject unsuitable for enrollment.
