This research study is evaluating a modified FOLFIRINOX plus bevacizumab therapy for mucinous ovarian cancer, fallopian tube cancer, and primary peritoneal cancer.

This study is aimed at recurrent/metastatic/resectable patients who have received systemic chemotherapy of 2nd line or less. Excludes previously diagnosed mucinous tumors of gastrointestinal origin through upper and lower endoscopy and pathologic immunohistochemical staining.

Bevacizumab plus modified FOLFIRINOX drug is administered every 2 weeks. To prevent neutropenia fever during chemotherapy, pegteograstim is given 24 hours after chemotherapy.

The primary objective of this study is the objective response rate (ORR). The secondary objectives are progression-free survival (PFS) and disease control rate at 6 months after administration, disease control rate (DCR), overall survival (OS), drug safety, and quality of life improvement as assessed by patient questionnaires.

In addition, the investigators intend to explore biomarkers that can predict the effect of bevacizumab + mFOLFIRINOX combination therapy through the collection of tumor samples and blood samples for exploratory purposes.

Inclusion Criteria:

1. Patients with recurrent, metastatic, or unresectable ovarian cancer, fallopian tube cancer, or primary peritoneal cancer diagnosed cytologically or histologically as mucinous cancer.

   *Subjects who are metastatic (stage IV) or mucinous ovarian cancer that cannot be surgically resected at diagnosis may have undergone cytoreductive surgery prior to systemic chemotherapy. It is appropriate for participation in this study if there are residual lesions after surgery and other selection criteria are met.

2. Mucous tumors of gastrointestinal origin should be excluded by prior upper and lower intestinal endoscopy and pathologic immunohistochemical staining (CEA, SATB2, etc.).

3. Patients who have not received previous systemic chemotherapy for recurrent, metastatic, or unresectable ovarian, fallopian tube, or primary peritoneal cancer, or who have failed second-line or less systemic chemotherapy. However, immunotherapy alone (eg, anti-PD-1 or anti-PD-L1 immunotherapy) is not included in previous chemotherapy.

   *Platinum susceptibility does not affect the selection/exclusion criteria for this trial.

4. Informed consent

5. Age more than 19 years old

6. Patients with measurable lesions according to RECIST v1.1.

7. ECOG Performance score 0-2

8. Patients with adequate organ function

9. Women of childbearing potential must either have a negative pregnancy test on a urine or serological test or consent to the use of an appropriate contraceptive method.

Exclusion Criteria:

1. Patients who have previously received systemic chemotherapy, including oxaliplatin or irinotecan. *Previous treatment with bevacizumab is acceptable.
2. Pregnant or breastfeeding women
3. Patients who received chemotherapy, targeted small-molecule agents, or radiotherapy within 2 weeks prior to Day 1 of the study, or who have not yet recovered (Grade 1 or lower or baseline level) from a previously administered drug-induced adverse event.
4. Active central nervous system (CNS) metastases and/or carcinoma meningitis.
5. Patients with known aggravation within the past 3 years or other malignant tumors requiring aggressive treatment.
6. Patients with moderate acute or chronic medical conditions or abnormal findings on examination, which are judged to affect the results of this study
7. Infected with Human Immunodeficiency Virus (HIV) (HIV-1/2 antibody) infection or active hepatitis B (HBsAg positive and HBV DNA ≥100 copies/ml) or hepatitis C (anti-HCV antibody positive and HCV RNA detected) being)
8. Clinically significant heart disease.