Efficacy and safety of recombinant human adenovirus type 5 (H101) combined with immune checkpoint inhibitors (ICIs) in patients with liver metastatic gastric cancer: A prospective multicenter phase II study (the TROJAN 021 study).

Abstract

2635 Background: Immune checkpoint inhibitors (ICIs) have shown significant efficacy in metastatic gastric cancer, but some patients may not respond to them because of immune resistance. Recombinant Human Adenovirus Type 5 (H101), the world’s first oncolytic virus antitumor drug in China, can induce cell death, expose tumor antigens, provide adjuvants for anti-tumor immune priming, and potentially increase responsiveness to immunotherapies. Here, we presented the efficacy and safety of H101 combined with immune checkpoint inhibitors (ICIs) in patients with liver metastatic gastric cancer. Methods: In this multi-center, phase II trial (the TROJAN 021 study, ChiCTR1900027922), patients with liver metastatic gastric cancer received 2 cycles of H101 ultrasound guided injections into liver lesions, bi-weekly in combination with anti-PD-1 antibodies and chemotherapy bi-weekly until progression or intolerable toxicity. The primary objective was safety and objective response rate (ORR). Secondary objective included progression-free survival (PFS), overall survival (OS) and disease control rate (DCR). Efficacy assessments were performed every 4 weeks following RECIST v1.1 criteria. PFS and OS were estimated using the Kaplan-Meier method. Results: From September 2020 to September 2022, 21 patients were enrolled. Of them, 18 were males, median age was 66 years (range: 36-71) and ECOG performance status was either 0 (n=15) or 1 (n=6). 10 patients (47.6%) received as first-line therapy, 1 (4.8%) as second-line and 5 (23.8%) as third line and above therapy. The primary endpoint was met with a median PFS of 4.8 months. The median OS was 13.2 months. Objective tumor responses were CR (n=0), PR (n=7), SD (n=12) and PD (n=2). ORR was 33.3% (7/21), and DCR was 90.5% (19/21). Treatment related adverse events (TRAE) occurred in 12 patients (57.1%). The most frequently observed TRAEs were injection site pain (48.1%), fever (57.1%) and fatigue (23.8%). Three patients (14.3%) had grade 3 treatment-related adverse events. There were no grade 4 and 5 treatment-related adverse events. Grades 3 toxicities included neutropenia (2/21, 9.5%) and hypertension (1/21, 4.8%). Conclusions: These promising results show that combination of Recombinant Human Adenovirus Type 5 (H101) and ICIs demonstrated acceptable toxicity and promising antitumor efficacy in patients with liver metastatic gastric cancer. Further validation of the efficacy in a randomized prospective trial is warranted. Clinical trial information: ChiCTR1900027922.