The study is being conducted to: a) evaluate the tolerability and safety of the co-administration of Fluzoparib and mFOLFIRINOX followed by Fluzoparib Maintenance Monotherapy in patients with advanced pancreatic cancer, and establish the maximum tolerated dose and recommended phase II dose of the combination; and b) assess the efficacy of the co-administration of Fluzoparib and mFOLFIRINOX followed by Fluzoparib Maintenance Monotherapy in patients with advanced pancreatic cancer.

Inclusion Criteria:

• Aged ≥ 18 years.
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1
• Expected survival ≥ 6 months.
• Histologically or cytologically confirmed local advanced/metastatic pancreas adenocarcinoma.
• Documented mutation in germline BRCA1/2 or PALB2 that is predicted to be deleterious or suspected deleterious.
• Adequate organ performance based on laboratory blood tests.
• Presence of at least of one measurable lesion in agreement to RECIST criteria.
• Women of childbearing potential and men must agree to use adequate contraception prior to study entry and for the duration of study participation.
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Patients who have received any chemotherapy for the treatment of pancreatic cancer prior to entering the study.
• Previous treatment with any poly ADP-ribose polymerase (PARP) inhibitor.
• Patients who have had radiotherapy or participated in another clinical trial with any investigational agents within 28 days of enrolment (Day 1 visit).
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to oxaliplatin, irinotecan, 5-Fluorouracil or other agents used in the study.
• Previous treatment using CYP3A4 inducers within 3 weeks or inhibitors within 2 weeks of enrolment (Day 1 visit).
• Patients with known or suspected brain metastasis.
• Significant cardiovascular disease such as New York Heart Associate Class III/IV, cardiac failure, myocardial infarction, unstable arrhythmia, or evidence of ischemia on ECG within 6 months prior to enrolment.
• Patients unable to swallow orally administered medication and patients with gastrointestinal disorders likely to interfere with absorption of the study medication.
• Patients with myelodysplastic syndrome/acute myeloid leukaemia.
• Patients with second primary cancer except curatively treated in-situ cancer or slowly progressing malignancy.
• Known active hepatitis B or C infection.
• History of immunodeficiency (including HIV infection) or organ transplantation.
• Other serious accompanying illnesses, which, in the researcher's opinion, could seriously adversely affect the safety of the treatment.