Long-term outcome was in line with published results, morbidity was acceptable and there was no 100-day mortality. The results reemphasize CRS-HIPEC as an important treatment option in PM-CRC, with particularly good results in patients with PCI < 12. J. Surg. Oncol. 2016;114:222-227. © 2016 Wiley Periodicals, Inc.

Peritoneal metastasis (PM) is an important feature of epithelial ovarian cancer (EOC) and is a frequent site of drug resistant disease recurrence, identifying PM-EOC an important clinical challenge. The MOC31PE immunotoxin targets and kills tumor cells expressing the epithelial cell adhesion molecule (EpCAM), which is highly expressed in EOC, and MOC31PE is being investigated for use in treatment of PM-EOC. The efficacy of MOC31PE treatment alone and in combination with cytotoxic drugs was investigated in two human EpCAM expressing EOC cell lines, B76 and MDHA-2774, in vitro and in corresponding mouse models mimicking PM-EOC. MOC31PE efficaciously killed tumor cells alone and showed equal or superior activity in vitro (paclitaxel, cisplatin, carboplatin) and in vivo (paclitaxel, mitomycin C) compared to the investigated cytotoxic drugs. Additive, or importantly, no antagonistic effects were observed in combination experiments. In ex vivo cell culture, the cytotoxic effect of MOC31PE was studied on freshly isolated surgical EOC samples. All investigated fresh EOC samples expressed EpCAM and MOC31PE effectively reduced cell viability in ex vivo cultures. In conclusion, these results, together with our previous preclinical and clinical experience, support development of MOC31PE for treatment of PM-EOC in combination with currently used cytotoxic drugs.

Background Despite extensive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), most patients with resectable peritoneal metastases from colorectal cancer experience disease relapse. MOC31PE immunotoxin is being explored as a novel treatment option for these patients. MOC31PE targets the cancer-associated epithelial cell adhesion molecule, and kills cancer cells by distinct mechanisms, simultaneously causing immune activation by induction of immunogenic cell death (ICD). Methods Systemic and local cytokine responses were analyzed in serum and intraperitoneal fluid samples collected the first three postoperative days from clinically comparable patients undergoing CRS-HIPEC with (n = 12) or without (n = 26) intraperitoneal instillation of MOC31PE. A broad panel of 27 pro- and antiinflammatory interleukins, chemokines, interferons, and growth factors was analyzed using multiplex technology. Results The time course and magnitude of the systemic and local postoperative cytokine response after CRS-HIPEC were highly compartmentalized, with modest systemic responses contrasting substantial intraperitoneal responses. Administration of MOC31PE resulted in changes that were broader and of higher magnitude compared with CRS-HIPEC alone. Significantly increased levels of innate proinflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF) as well as an interesting time response curve for the strong T-cell stimulator interferon (IFN)-γ and its associated chemokine interferon gamma-induced protein/chemokine (C-X-C motif) ligand 10 (IP-10) were detected, all associated with ICD. Conclusions Our study revealed a predominately local rather than systemic inflammatory response to CRS-HIPEC, which was strongly enhanced by MOC31PE treatment. The MOC31PE-induced intraperitoneal inflammatory reaction could contribute to improve remnant cancer cell killing, but the mechanisms remain to be elucidated in future studies.