High Rates of Complete Remission in B-Cell Malignancies With CAR T-Cells Cultured Using Faster Technique

Treatment of patients with relapsed/refractory B-cell malignancies by CAR T-cells cultured using a new technique achieved high complete remission (CR) rates, according to a study published in the Journal of Clinical Oncology (online: May 20, 2018; doi:10.1200/JCO.2018.36.15_suppl.7034).

Lu Han, Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital (Zhengzhou, China), and colleagues explore methods to simplify the preparation for anti-CD19 chimeric antigen receptor (CAR) T-cells for relapsed/refractory B-cell malignancies .

Researchers extracted 50-100 mL peripheral blood from patients, and, after 7 to 10 days, cultured CAR T-cells were given back to the patients. Researchers reported that CAR T-cells were capable of large numerical expansion in 7 to 10 days, at rates up to about 500 million magnitudes. The culture success rate reached 100%.

All patients received a chemotherapy a cyclophosphamide and fludarabine followed by 1 to 3 million CAR T-cells/kg. A total of 29 patients with relapsed/refractory B-cell malignancies—17 patients with acute lymphoblastic leukemia (ALL) and 12 patients with B-cell lymphoma—were treated.

CR was achieved in 16 ALL patients 1 month after CAR T-cell infusion. Of these patients, 15 patients were minimal residual disease-negative, except for one patient who died from cytokine release syndrome. The CR rates for ALL patients were 71.4% at 3 months and 56.0% at 6 months. A total of 12 patients experienced cytokine release syndrome, including 11.76% of patients with ALL. 

Of the 12 patients with B-cell lymphoma, four achieved CR, five achieved partial remission, and three had progressive disease when evaluated at 2 months. The CRs and overall response were 37.5% and 50.0% at 6 months, respectively. Two B-cell lymphoma patients were observed with cytokine release syndrome. 

“Treatment of relapsed/refractory B-cell malignancies with a high complete remission by CAR-T cells… cultured from 50-100 mL peripheral blood… achieved larger amount of amplification in short time,” authors concluded. “These results could be benefit for more high-risk patients.”—Janelle Bradley