Clinical Study of mRNA Vaccine Combined With PD-1 Inhibitor as Adjuvant Therapy for Postoperative Pancreatic Cancer

• Fixed neoantigen tumor vaccine (Biological): Single/Fixed neoantigen mRNA vaccine includes pancreatic cancer driver mutations such as KRAS G12D, G12V, G12R, G12C, etc. Each vaccine has one neoantigen encoded by mRNA. Total of 4 cycles, 3 weeks each cycle.
• personalized neoantigen tumor vaccine (Biological): personalized neoantigen tumor vaccine include 5-20 neoantigens selected based on WES/RNA-seq of patients' tumor sample during surgery. Total of 9 cycles after finishing the first 4 cycles of fixed neoantigen tumor vaccine.
• PD-1 inhibitor (Drug): Toripalimab

Primary outcomes

• Drug related toxicity [18 months]: Percentage Participants with Adverse Events (AEs) by severity According to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0

Secondary outcomes

• Recurrence-free survival (RFS) [Up to 18 months]: Recurrence-free survival of Personalized mRNA Tumor Vaccine
• overall survival (OS) [Up to 18 months]: Overall Survival of Personalized mRNA Tumor Vaccine
• Reaction of antigen-specific T cells in peripheral blood [Up to 18 months]: personalized tumor vaccine induced neoantigen-specific CD4+ and CD8+ T lymphocyte responses

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Subjects voluntarily signed written informed consent files,Able to comply with the study protocol, in the investigator's judgment
2. Subjects must be >/= 18 years of age at time of informed consent, regardless of gender
3. Patients who have been confirmed by pathology to have pancreatic malignant tumors and have undergone radical surgery for pancreatic malignant tumors for 1-3 months
4. No copy number variations (CNVs) or loss of heterozygosity (Loss-of heterozygosity, LOH) were found in HLA-related genes and chromosomal regions by gene sequencing
5. Histologically confirmed pancreatic cancer samples underwent WES and RNA-seq analyses. Bioinformatics prediction identified at least one neoantigen effectively presented by the patient's HLA type, including those derived from KRAS or TP53 mutations.
6. According to the investigator's assessment, the patient is unable to tolerate chemotherapy, such as the score of the Eastern Cooperative Oncology Group (ECOG) Performance Scale ≥ 2 points

Exclusion Criteria:

1. Has had chemotherapy, traditional Chinese medicine with antitumor indications, or other antitumor therapies deemed to conflict with the current treatment by the investigator within 4 weeks prior to the first administration of the study drug
2. History of interstitial lung disease (ILD), pulmonary fibrosis
3. Other serious and/or uncontrollable diseases, which may affect the subject's participation in this study, include but not limited to a) a history of severe drug allergy, or is known to be allergic to any tumor vaccine and PD-1 inhibitor formulation components or has had severe allergic reactions to other monoclonal antibodies in the past, b) A history of immunodeficiency, including HIV positive or other acquired or congenital immunodeficiency diseases
4. Researchers believe that there are other reasons that are not suitable for participating in clinical trials

• Baiyong Shen, M.D&Ph.D, Study director, Ruijin Hospital