Intraperitoneal immunotherapy with the bispecific anti-EpCAM x anti-CD3 directed antibody catumaxomab for patients with peritoneal carcinomatosis from gastric cancer: Final results of a randomized phase II AIO trial

• Published in: Journal of clinical oncology Vol. 36; no. 4_suppl; p. 4
• Main Authors: Lordick, Florian, Kunzmann, Volker, Trojan, Jorg, Daum, Severin, Schenk, Michael, Kullmann, Frank, Schroll, Sebastian, Behringer, Dirk M., Stahl, Michael, Al-Batran, Salah-Eddin, Ibach, Stefan, Koerfer, Justus, Knoedler, Maren Kristina
• Format: Journal Article
• Language: English
• Published: 01.02.2018
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2018.36.4_suppl.4

Abstract only 4 Background: The peritoneal surface is a common location for metastases in gastric cancer (GC). Intraperitoneal (i.p.) application of the bispecific (anti-EpCAM/CD3) monoclonal antibody catumaxomab (CATU) in addition to i.v. chemotherapy may improve elimination of peritoneal carcinomatosis (PC). Methods: This randomized open-label phase II study aimed to investigate the efficacy of i.p. CATU following i.v. chemotherapy in patients (pts) with GC and PC (Gilly stages P1-4). Pts were randomly allocated to receive four cycles of FLOT (5FU, LV, Oxaliplatin, Docetaxel) followed by i.p. CATU at escalating doses (10, 20, 50, 150µg) on days 0, 3, 7, 10 or FLOT alone. Secondary gastrectomy and peritonectomy were allowed to achieve complete resection of all malignant lesions. The primary endpoint was to show an increased rate of macroscopic complete remission of PC at second-look surgery. Secondary endpoints included toxicity, progression-free and overall survival (PFS/OS). Results: Of 35 pts screened, 31 were enrolled. Median follow-up time is 52 months. 15 pts were allocated to FLOT-CATU (arm A) and 16 to FLOT alone (arm B). Complete remission rate of PC was 27% in arm A and 19% in arm B (p = 0.69). Severe side effects with i.p. CATU were nausea (15%), fever (23%), abdominal pain (31%), and elevated liver enzymes (gGT 31%, bilirubin 23%). Adverse events tended to be more common during FLOT-CATU compared to FLOT alone. Median PFS was not significantly different in both arms with 6.7 months in arm A compared to 5.4 months in arm B (p = 0.71). Median OS was 13.2 and 13.0 months. Conclusions: Addition of i.p. CATU as part of a multimodal treatment approach revealed feasible and tolerable in pts with GC and PC. Although the primary endpoint was not met, the results are promising for future trials investigating i.p. immunotherapy in this patient population. Clinical trial information: NCT01504256.