**Study Purpose:** The study looks at using a new drug, setidegrasib, with chemotherapy to treat pancreatic cancer. Pancreatic cancer is hard to find early and often spreads (metastatic) before being diagnosed, making it hard to treat. Chemotherapy is a common treatment, but this study tests if adding setidegrasib helps people live longer and delays cancer returning. It focuses on patients with a specific gene change (KRAS G12D mutation) in their cancer. **Important Study Details:** - **Who Can Join:** Adults with pancreatic cancer that has spread and have the KRAS G12D mutation. Surgery or radiation isn't an option for them. - **Treatment:** Participants may get setidegrasib with mFOLFIRINOX or NALIRIFOX chemotherapy, or a placebo with one of these chemotherapies. Treatment continues until cancer worsens or other specified conditions occur. - **Exclusions:** Participants can't join if they have cancer in the brain, other recent cancers needing treatment, or certain health problems like severe bowel disease. This study helps understand if setidegrasib is a safe and effective treatment option for pancreatic cancer.