A Study of the Efficacy and Safety of Adjuvant Autogene Cevumeran Plus Atezolizumab and mFOLFIRINOX Versus mFOLFIRINOX Alone in Participants With Resected Pancreatic Ductal Adenocarcinoma (IMCODE003)

Inclusion Criteria: Histologically confirmed diagnosis of PDAC Pancreatic cancer tumor, lymph node, metastasis (TNM) pathological staging values of T1-T3, N0-N2, and M0 per the American Joint Committee on Cancer (AJCC) Cancer Staging Manual Macroscopically complete (R0 or R1) resection of PDAC Unequivocal absence of disease after surgery as assessed by the investigator within 28 days prior to randomization CA19-9 level measured within 14 days prior to randomization Interval of between 6 and 12 weeks since resection of PDAC Full recovery from surgery and ability to receive atezolizumab, autogene cevumeran, and mFOLFIRINOX in the investigator's judgment Adequate hematologic and end-organ function Female participants of childbearing potential must be willing to avoid pregnancy during the treatment period and for 90 days after the final dose of autogene cevumeran, for 6 months after the last dose of chemotherapy, and for 5 months after the final dose of atezolizumab. Male participants with a female partner of childbearing potential or pregnant female partner must remain abstinent or use specified contraceptive methods during the treatment period and for 28 days after the final dose of autogene cevumeran and for 6 months after the last dose of chemotherapy. Men must refrain from donating sperm during this same period. Exclusion Criteria: Prior adjuvant, neoadjuvant, or induction treatment for pancreatic cancer Absence of spleen; distal pancreatectomy with splenectomy is exclusionary Pregnancy or breastfeeding Active or history of autoimmune disease or immune deficiency