CD19 CAR-T 细胞治疗使伴微小残留病的 B-ALL 患者获得持续缓解

The persistence or recurrence of minimal residual disease (MRD) after chemotherapy predicts relapse of B-cell acute lymphoblastic leukemia (B-ALL). CD19-directed chimeric antigen receptor T (CD19 CAR-T) cells have shown promising responses in B-ALL.

However, their role in chemotherapy-refractory MRD-positive B-ALL remains unclear.

Here we aimed to assess the effectiveness and safety of CD19 CAR-T cells in MRD-positive B-ALL patients. From January 2018, a total of 14 MRD-positive B-ALL patients received one or more infusions of autogenous CD19 CAR-T cells. Among them, 12 patients achieved MRD-negative remission after one cycle of CAR-T infusion.

At a median follow-up time of 647 days (range 172-945 days), the 2-year event-free survival rate in MRD-positive patients was 61. 2% 14. 0% and the 2-year overall survival was 78. 6 11. 0%, which were significantly higher than patients with active disease (blasts 5% or with extramedullary disease).

Moreover, patients with MRD had a lower grade of cytokine release syndrome (CRS) than patients with active disease.

However, the peak expansion of CAR-T cells in MRD positive patients showed no statistical difference compared to patients with active disease. Five patients received two or more CAR-T cell infusions and these patients showed a decreased peak expansion of CAR-T cell in subsequent infusions.

In conclusion, pre-emptive CD19 CAR-T cell treatment is an effective and safe approach and may confer sustained remission in B-ALL patients with chemotherapy-refractory MRD. The trials were registered at www. chictr. org. cn as ChiCTR-ONN-16009862 (November 14, 2016) and ChiCTR1800015164 (March 11, 2018).