Long-Term Follow-Up of CD19 CAR-T for R/R B-NHL: Ki-67 as a Prognostic Factor for Sustained Remission

Patients with relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL) typically experience dismal outcomes. Although CD19 chimeric antigen receptor T-cell (CAR-T) therapy has shown considerable efficacy, the factors influencing its long-term efficacy remain unclear. We retrospectively analyzed 79 R/R B-NHL patients treated with CD19 CAR-T cell therapy at our center to evaluate efficacy, long-term survival, and prognostic factors. Among all evaluable patients, the overall response rate was 89.7%, with a 3-year duration of response (DOR) of 44.9% (95% CI, 34.2%-59.0%), a 3-year progression-free survival (PFS) of 40.2% (95% CI, 30.3%-53.4%), and a 3-year overall survival (OS) of 48.3% (95% CI, 38.0%-61.3%). Long-term adverse events (AEs) included hypogammaglobulinemia, which occurred in 73 of 74 evaluable patients (92.4%), viral reactivation (5.1%), and secondary malignancy (5.1%). Notably, high tumor Ki-67 (>60%) was associated with lower peak CAR-T cell expansion (P < .01), reduced area under the curve of expansion from day 0 to 28 (P < .0001), and inferior complete response rate, DOR, and PFS (all P < .05). However, CAR-T cell persistence was not significantly associated with long-term remission or survival (all P > .05). In conclusion, CD19 CAR‑T cell therapy yielded sustained remissions in patients with R/R B-NHL, with manageable long-term AEs. High tumor Ki‑67 expression serves as a poor prognostic factor and is linked to limited CAR‑T cell expansion, whereas CAR‑T cell persistence does not influence long-term prognosis.