Study on the Prognostic Value of Aberrant Antigen in Patients With Acute B Lymphocytic Leukemia.

BACKGROUND: Approximately 30% to 60% of patients with acute B-lymphocytic leukemia (B-ALL) show as refractory or relapsed, which is one of the major causes of death in patients with B-ALL, but the methods of the treatment for relapsed/refractory B-ALL (R/R B-ALL) are limited. The chimeric antigen receptors redirected T cells (CAR-T cells) have showed a strong anti-leukemia role for B-ALL. About 90% of patients with R/R B-ALL treated with CD19-CAR-T cells achieved complete remission. However, 60% to 70% of patients relapsed after CAR-T cells treatment, which may be related to target antigen reduction or escape. New products are urgently needed to prevent and treat antigenic escapes causing recurrence. PATIENTS AND METHODS: In this article, we retrospectively analyzed the immunophenotype of patients with B-ALL initially diagnosed in our center from January 2010 to December 2015 to determine whether aberrant antigen expression was associated with the prognosis of patients in order to find new targets for immunotherapy. RESULTS: The results show that disease-free and overall survival in patients without aberrant antigen expression were better than patients with aberrant antigen expression. The most common abnormal antigens were CD123, CD13, and CD56. Correlation analysis showed a negative correlation between aberrant CD123 expression and both disease-free and overall survival. CONCLUSION: Therefore, in the construction of CAR-T cells in patients with R/R B-ALL, conventional CD19 can be combined with aberrant antigens such as CD123 to form CARs with bi-specific antigens or multi-specific antigens may achieve the purpose of improving efficacy. However, more clinical trials are needed.

Alemtuzumab in chronic lymphocytic leukemia: final results of a large observational multicenter study in mostly pretreated patients.

This retrospective study evaluated the benefit of alemtuzumab monotherapy in unselected patients with advanced B-cell chronic lymphocytic leukemia (CLL) and prolymphocytic leukemia (B-PLL) to definitely describe the impact of this antibody in clinical routine use. Data were collected from 208 consecutive, mainly pretreated, patients with CLL (n = 202), and B-PLL (n = 6) who had received alemtuzumab. Response, progression-free survival (PFS), and overall survival (OS) in various settings were assessed, and toxicities were documented. In these routine patients, a comparably low cumulative dose of alemtuzumab (median, 403 mg) was applied. In CLL, overall response rate was 32 %, and various pre-therapeutic parameters were predictive for inferior response, among them, the prior administration of ≥3 therapy lines (P < 0.001), refractoriness to fludarabine (P = 0.002), and bulky lymphadenopathy (P = 0.003). PFS and OS after start of alemtuzumab were 6.2 and 21.0 months, respectively. Bulky lymphadenopathy was the prominent risk factor for both inferior PFS (P < 0.001) and OS (P = 0.002). In B-PLL, four patients experienced a fatal outcome, whereas two patients had some benefit with alemtuzumab. The main adverse effects were CMV reactivation (20 %) and a broad spectrum of infections, which together were the main reasons for treatment interruption and/or premature termination. In conclusion, alemtuzumab administered even at low dose levels was effective but overall considerably toxic in routine CLL patients. We emphasize that alemtuzumab remains an important therapeutic option in subsets of CLL patients.