A single-arm exploratory clinical study of β-glucan combined with camrelizumab and SOX chemotherapy as first-line treatment for advanced gastric adenocarcinoma.

Abstract

e16008 Background:The combination of immunotherapy plus chemotherapy has revolutionized the therapy pattern of advanced gastric adenocarcinoma, but the efficacy is still unsatisfactory. β-glucan has been reported to be a potential natural immune modulator for tumor growth inhibition. Therefore, we aimed to evalute the efficacy and safety of β-glucan plus immunotherapy and chemotherapy in the first-line treatment of advanced gastric adenocarcinoma. Methods:This is a prospective, single-arm, investigator-initiated trail. All included patients are adults with advanced gastric adenocarcinoma, and with an Eastern Cooperative Oncology Group (ECOG) score ≤ 2. Eligible patients received WGP β-glucan (500 mg; twice daily on days 1-14) + camrelizumab (day 2; fixed-dose 200 mg) + oxaliplatin (day 1; 130 mg/m2)+ oral S-1 (twice daily on days 1-14; body surface area < 1.25 m2: 40 mg; body surface area 1.25-1.5 m2: 50 mg; body surface area > 1.5 m2: 60 mg) every 3 weeks. The curative effect is evaluated (RECIST 1.1) every 2 cycles. Safety evaluation indicators include vital signs, laboratory indicators and treatment-related adverse events (TRAEs). The primary endpoints were objective response rate (ORR) and safety; the secondary endpoints were median progression-free survival (mPFS) and median overall survival (mOS); the exploratory endpoint treatment-related biomarker changes from liquid biopsies. Results:From April 2021 to October 2022, a total of 30 patients with average of 67.5 years old had been enrolled, incuding 20 (66.7%) males and 8 (26.7%) patients with an ECOG PS score of 2. The ORR was 60%; the mPFS was 10.4 months (95% confidence interval [CI], 9.52-11.27); the mOS was 14.0 months (95% CI, 11.09-16.91). A total of 19 patients (63.3%) had TRAEs, with 9 patients (30%) with grade ≥ 3. The most common treatment-related adverse events were nausea (53.3%) and hemangioma (33.3%). No TRAEs associated with β-glucan were observed. After 2 cycles of treatment, the levels of IL-2 and IFN-γ significantly increased ( P < 0.05), and the number of CD4+ T cells also significantly increased ( P < 0.05). Furthermore, the protein expressions of GZMA, GZMH, and CD244 were significantly lower in the responding group (CR+ PR) than in the non-responding group (SD + PD) (P < 0.05). Conclusions: This preliminary study demonstrates that β-glucan plus camrelizumab and SOX chemotherapy offers favorable efficacy and a manageable safety profile in patients with advanced gastric adenocarcinoma, and further studies are needed to verify its efficacy and safety. Clinical trial information: ChiCTR2100044088.