Metformin in Pseudomyxoma Peritonei Secondary to Appendiceal Mucinous Neoplasms

Key Inclusion Criteria (complete details available in protocol): * Patients with clinical diagnosis of pseudomyxoma peritonei (PMP) secondary to presumed appendiceal mucinous neoplasms (AMNs) with recurrent/refractory disease s/p cytoreductive surgery(CRS)/hyperthermic intraperitoneal chemotherapy (HIPEC), unresectable disease, or without planned CRS/HIPEC * Age ≥18 years * ECOG performance status ≤2 Key Exclusion Criteria (complete details available in protocol): * Patients with a clinical diagnosis of PMP secondary to presumed AMNs with resectable disease who are planned to undergo CRS/HIPEC * Patients currently taking metformin for another medical indication * Patients with a prior adverse event to administration of metformin