Immunotherapy of Peritoneal Carcinomatosis with the Antibody Catumaxomab in Colon, Gastric, or Pancreatic Cancer: An Open-Label, Multicenter, Phase I/II Trial

Background: Peritoneal carcinomatosis (PC) is common in
gastrointestinal (GI) cancer and there is no effective standard
treatment. We investigated the tolerability and maximum tolerated
dose (MTD) of the trifunctional antibody catumaxomab in patients
with PC. Methods: In this open-label, phase I/II clinical trial,
patients with epithelial cell adhesion molecule (EpCAM)-positive PC
from GI cancer received 4 sequential intraperitoneal catumaxomab
infusions: day 0: 10 mu g; day 3: 10 or 20 mu g; day 7: 30, 50, or
100 mu g; and day 10: 50, 100, or 200 mu g. Dose escalation was
guided by dose-limiting toxicities. Results: The MTD was 10, 20,
50, and 200 mu g on days 0, 3, 7, and 10, respectively. Catumaxomab
had an acceptable safety profile: Most common treatment-related
adverse events (at the MTD) were fever, vomiting, and abdominal
pain. At final examination, 11/17 evaluable patients (65%) were
progression free: 1 patient had a complete and 3 a partial
response. Median overall survival from the time of diagnosis of PC
was 502 days. Conclusions: Intraperitoneal catumaxomab is a
promising option for the treatment of PC from GI cancer.