A phase II study of catumaxomab administered intra- and postoperatively as part of a multimodal approach in primarily resectable gastric cancer.

BACKGROUND: Postoperative relapse rate after gastrectomy and perioperative chemotherapy remain high in patients with advanced gastric cancer due to the spread of disseminated tumour cells in the peritoneal cavity. Perioperative administration of catumaxomab could potentially eliminate residual tumour cells after intended curative resection of the primary tumour. METHODS: This open-label, phase II study investigated the safety and efficacy of catumaxomab following neoadjuvant chemotherapy and subsequent surgery in patients with resectable (T2-4, N+, M0) gastric adenocarcinoma. Patients received catumaxomab intra- (single 10 µg dose) and postoperatively (10, 20, 50 and 150 µg on days 7, 10, 13 and 16, respectively). The primary endpoint was the postoperative complication rate (maximum rate defined as <62 %) within 30 days after surgery in patients who received at least the first catumaxomab dose. RESULTS: Of 64 patients treated with neoadjuvant chemotherapy, 58 underwent surgery and 54 received at least the first catumaxomab dose. Postoperative complications were reported in 18 of 54 evaluable patients (complication rate 33 %; 95 % confidence interval: 21-48 %); thus, the primary endpoint was met. The most frequent complications were pulmonary infection (17 %) and anastomosis insufficiency requiring surgery (11 %). The most common catumaxomab-related adverse events were pyrexia (67 %), leucocytosis (19 %), abdominal pain (17 %) and chills (17 %). The 4-year disease-free and overall survival rates were 38 and 50 %. CONCLUSION: Intra- and postoperative administration of catumaxomab as part of a multimodal treatment approach was feasible and tolerable in patients with advanced gastric cancer and should be further investigated in a randomised trial.