PD-1 inhibitors combined with apatinib for advanced diffuse gastric cancer: A retrospective study.

Abstract

e16009 Background: Numerous studies have shown that immunotherapy has a synergistic effect when combined with targeted drug therapy. Apatinib has been proven effective in advanced gastric cancer. Based on these facts and to assess the efficacy and safety of programmed death 1 (PD-1) inhibitors and apatinib as combination therapy in patients (pts) with unresectable locally advanced or metastatic diffuse gastric cancer(DGC), a retrospective clinical research study was carried out. Methods: Retrospective analysis of a cohort of pts with advanced diffuse gastric cancer received treatment of apatinib combined with PD-1 inhibitors enrolled in our institution between January 2019 and January 2021.Pts (n = 34) received PD-1 inhibitors and apatinib (250mg once daily) in this retrospective study. Overall survival (OS) and progression free survival (PFS) were estimated by Kaplan Meier curves, and other endpoints included objective response rate(ORR), disease control rate(DCR), prognostic factors. Results: A total of 34 pts were enrolled in a real-world dataset from Henan Cancer Hospital. 2 pts achieved partial response(PR),17 pts had stable disease(SD),and 15 pts had progressive disease (PD). The ORR and DCR were 5.88% (2/34) and 55.88% (19/34), respectively. The median PFS(mPFS) was 2.47 months (95%CI:1.9-3.0), and the median OS (mOS) was 6.80 months (95%CI 3.7-9.9). Pts with less than 3 metastatic sites had longer mOS than those with more metastatic sites(2.70 vs. 7.73 P < 0.05). And in this study, the levels of platelet, albumin, CEA, CA199, CA125 and LDH affect patients’ prognosis. Kaplan-Meier analyses revealed that patients with normal platelet had better mOS than those with higher platelet(mOS 7.10 vs 0.3; P < 0.05).And similar results were found in the pts with normal albumin. The mOS of those was longer than the pts with lower or higher albumin(7.73 vs 2.20 vs 2.53, P < 005). And we demonstrated that positive groups of CEA(> 4.7ng/ml), CA125(> 35U/ml), CA199(> 27U/ml) and LDH(> 245U/L) were significantly associated with worse outcomes than that of negative groups(all P < 0.05). The incidence of grade 3 or 4 treatment-related adverse events (TRAEs) was 26.5%(9/34). These adverse events (AEs) included pruritus, rash, hand-foot syndrome, hypertension and increased aspartate aminotransferase (AST) or alanine aminotransferase (ALT). No treatment-related deaths occurred. Conclusions: Combination therapy of PD-1 inhibitors and apatinib showed encouraging clinical activity and demonstrated tolerable toxicity in pts with advanced DGC. The level of platelet, albumin, CEA, CA199, CA125 and LDH could predict the prognosis of DGC patients.