TLR9 Immunotherapy for Peritoneal Carcinomatosis

The goal of this clinical trial is to determine the safety and efficacy of of ACM-CpG for inoperable peritoneal metastases or malignant ascites. The main questions it aims to answer are: • To determine the safety and maximum tolerated dose (MTD) or optimal biologic dose (OBD) of intraperitoneal injection(s) of ACM-CpG for inoperable peritoneal metastases or malignant ascites? Researchers will assign treatment levels using escalating doses of ACM-CpG Therapy. Participants will: * Will receive at least one dose of ACM-CpG therapy on Day 1 of a 28-day treatment cycle. * May receive up to 2 additional injections if they have clinically stable or responsive disease. * Must visit the clinic on Days 1, 4, 7, 10, 14, 21, and 28 for checkups and tests. * Will have a CT scan or MRI performed every 8 weeks for 3 scans and then continue to receive scans every 12 weeks to monitor their disease.