Observation on the efficacy of consolidation chemotherapy combined with allogeneic natural killer cell infusion in the treatment of low and moderate risk acute myeloid leukemia / 中华血液学杂志

ABSTRACT

Objective: To evaluate the efficacy of consolidation chemotherapy combined with allogeneic natural killer (NK) cell infusion in the treatment of low or intermediate-risk (LIR) acute myeloid leukemia (AML) . Methods: A cohort of 23 LIR AML patients at hematologic complete remission (CR) received NK cell transfusion combined with consolidation chemotherapy after 3 consolidation courses from January 2014 to June 2019 were reviewed. Control group cases were concurrent patients from Department of Hematology, and their gender, age, diagnosis, risk stratification of prognosis, CR and the number of courses of consolidate chemotherapy before NK cell transfusion were matched with LIR AML patients. Results: A total of 45 times of NK cells were injected into 23 LIR AML patients during 4 to 7 courses of chemotherapy. The median NK cell infusion quantity was 7.5 (6.6-8.6) ×10(9)/L, and the median survival rate of NK cells was 95.4% (93.9%-96.9%) . Among them, the median CD3(-)CD56(+) cell number was 5.0 (1.4-6.4) ×10(9)/L, accounting for 76.8% (30.8%-82.9%) ; The number of CD3(+) CD56(+) cells was 0.55 (0.24-1.74) ×10(9)/L, accounting for 8.8% (4.9%-20.9%) . Before NK cell infusion, the number of patients with positive MRD in the treatment and control groups were 9/23 (39.1%) and 19/46 (41.3%) (χ(2)=0.030, P=0.862) respectively. After NK infusion, There was no significant difference in terms of MRD that went from negative to positive between the treatment and the control groups (14.3% vs 22.2%, χ(2)=0.037, P=0.847) . In the treatment group, 66.7% (6/9) of the MRD were converted from positive to negative, which was significantly higher than that in the control group (10.5%, 2/19) (χ(2)=6.811, P=0.009) . Morphological recurrence occurred in 1 case of MRD negative in the treatment group and 2 cases of MRD positive in the control group. By the end of follow-up, the median follow-up was 35 (10-59) months, the number of patients with morphological recurrence in the treatment group was 30.4% (7/23) , which was significantly lower than that in the control group (50.2%, 24/46) (χ(2)=2.929, P=0.087) , although there was no statistically significant difference between the two groups. There was no significant difference on MRD-negative between the treatment and the control groups (43.5% vs 43.5%, χ(2)=1.045, P=0.307) . The 3-year leukemia-free survival was better in the treatment group [ (65.1±11.1) %] than that in the control group [ (50.0±7.4) %] (P=0.047) . The 3-year overall survival in the treatment and control groups were (78.1±10.2) % and (65.8±8.0) % (P=0.212) , respectively. Conclusion: The consolidation of chemotherapy combined with allogeneic NK cell infusion contributed to the further remission of patients with LMR AML and the reduction of long-term recurrence.