Efficacy and side effects of anti-CD19 CAR T-cell therapy in patients with relapsed/refractory gastrointestinal lymphoma

Introduction: Although anti-CD19 chimeric antigen receptor (CAR) T cell therapy was approved as a very effective salvage strategy in relapsed/refractory (R/R) B cell lymphoma, the experience in R/R gastrointestinal (GI) lymphoma is still insufficient. Methods: We summarized the efficacy and side effects of anti-CD19 CAR T-cell therapy in 12 patients with R/R GI lymphoma. Based on literature, the R/R GI lymphoma patients were divided into subgroups with different characteristics: Bulky/No bulky disease, Gastric/Gastrointestinal involvement, Gastrointestinal/Combined extra-gastrointestinal lesions, Ulcer/Lumps or nodules type, With/without gastrointestinal bleeding. Results: The objective response rate (ORR) was 66.67% in these 12 patients. The ORR was 83.33% in no bulky disease group, 80.00% in gastric involvement group, 100.00% in ulcer type group, and 80.00% in no gastrointestinal bleeding group. The CR rate was 33.33% in these 12 patients. The CR was 50.0% in no bulky disease group, 60.00% in gastric involvement group, and 80.00% in ulcer type group. The PFS and OS rate of the 12 patients at 6 months after infusion were 54.55% and 58.33%, respectively. The overall survival (OS) at 6 months was higher in no bulky disease group. There was no difference of the OS or the progression free survival (PFS) at 6 months between the other groups. The mean peak of CAR-T cells and Cytokine Release Syndrome (CRS) grade were higher in gastrointestinal lesions group. The mean peak of IFN-gamma and CRS grade were higher in gastrointestinal bleeding group. Four out of six patients in group of gastrointestinal lesions group were patient with high tumor burden. Patients with gastrointestinal involvement only were at higher risk for gastrointestinal bleeding. Conclusions: The ORR and CR of high tumor load, gastrointestinal involvement, lumps or nodules type and gastrointestinal bleeding group were lower. The CRS grade was higher in gastrointestinal lesions group and in gastrointestinal bleeding group. Patients with gastrointestinal involvement only were at higher risk for gastrointestinal bleeding.