Phase Ib/II Clinical Study of Adebrelimab in Combination With Decitabine, Albumin-bound Paclitaxel, and Gemcitabine for the First-line Treatment of Metastatic Pancreatic Cancer
Pancreatic cancer is a kind of digestive system tumor with extremely high malignancy and poor prognosis. Although the trend of benefit from immunotherapy in combination with chemotherapy is currently reflected in several exploratory studies, the overall efficacy is still relatively limited. Dysregulation of epigenetic mechanisms, which is common in cancer, leads to down-regulation of genes involved in tumor antigen processing or presentation, resulting in immune evasion and thus affecting the efficacy of immunotherapy. Epigenetic inhibitors may enhance the efficacy of immunotherapy by enhancing antigenicity and presentation of tumor-associated antigens, reprogramming the tumor microenvironment to counteract immunosuppression, and reversing cytotoxic T-cell depletion. Thus, decitabine-promoted immunotherapeutic sensitization is a potential therapeutic avenue for mPDAC patients that warrants further exploration in clinical trials. Taking into account the characteristics of pancreatic cancer immunophenotype, exploring combination therapy regimens that enhance anti-tumor immune response and improve the efficacy of immunotherapy has become an urgent clinical problem. This study is a prospective, single-arm, single-center, phase IB/II clinical study exploring the efficacy and safety of adebrelimab in combination with decitabine, albumin-bound paclitaxel, and gemcitabine in the first-line treatment of metastatic pancreatic cancer. The primary study endpoints are DLT, RP2D and ORR. Secondary study endpoints are OS, PFS, DCR, DoR and safety.
⁃ 1\. Age 18-75 years old, male or female; 2. Histologically or cytologically confirmed diagnosis of pancreatic cancer (originating from the pancreatic ductal epithelium), with clinical records showing metastatic pancreatic cancer (stage IV according to the AJCC 8th edition TNM staging of pancreatic cancer); 3. Have not received any anti-tumor therapy (including chemotherapy, targeted, immunotherapy, etc.); 4. Must have at least one measurable lesion as a target lesion (according to RECIST v1.1 criteria); the target lesion should not have received localized treatment such as radiotherapy (lesions located within the area of previous radiotherapy may also be selected as target lesions if progression is confirmed to have occurred and meets RECIST1.1 criteria); 5. ECOG: 0 to 1; 6. Expected survival ≥ 3 months; 7. Good major organ function, i.e., the following criteria are met (in the absence of receiving any blood components, cell growth factors within 14 days prior to randomization):
• Neutrophils ≥1.5\*109/L; platelets ≥80\*109/L; hemoglobin ≥9g/dl; serum albumin ≥3g/dl;
• Total bilirubin ≤ 1.5 times the upper limit of normal value (biliary obstruction allows biliary drainage); ALT and AST ≤ 3 times the upper limit of normal value (for patients with hepatic metastases, it can be relaxed to ≤ 5 times the upper limit of normal value);
• Serum creatinine ≤1.5 times the upper limit of normal value, creatinine clearance ≥50ml/min;
• INR ≤1.5 times the upper limit of normal value and APTT ≤1.5 times the upper limit of normal value (for the use of a stable dose of anticoagulation therapy, such as low molecular heparin or warfarin, and the INR is within the expected therapeutic range of anticoagulants can be screened);
• Electrocardiogram: QTcF ≤450ms (men), ≤470ms (women);
• Cardiac ultrasound: LVEF (left ventricular ejection fraction) ≥50%; 8. Women of childbearing potential must have had a negative blood pregnancy test within 3 days prior to randomization and be willing to use an appropriate method of contraception during the trial and for 6 months after completion of treatment. For men, this should be surgical sterilization or agreement to use an appropriate method of contraception for the duration of the study and for 3 months after completion of treatment; 9. Subjects voluntarily enroll in this study by signing an informed consent form.