In:
Blood, American Society of Hematology, Vol. 119, No. 26 ( 2012-06-28), p. 6226-6233
Abstract:
T cell–engaging CD19/CD3-bispecific BiTE Ab blinatumomab has shown an 80% complete molecular response rate and prolonged leukemia-free survival in patients with minimal residual B-lineage acute lymphoblastic leukemia (MRD+ B-ALL). Here, we report that lymphocytes in all patients of a phase 2 study responded to continuous infusion of blinatumomab in a strikingly similar fashion. After start of infusion, B-cell counts dropped to 〈 1 B cell/μL within an average of 2 days and remained essentially undetectable for the entire treatment period. By contrast, T-cell counts in all patients declined to a nadir within 〈 1 day and recovered to baseline within a few days. T cells then expanded and on average more than doubled over baseline within 2-3 weeks under continued infusion of blinatumomab. A significant percentage of reappearing CD8+ and CD4+ T cells newly expressed activation marker CD69. Shortly after start of infusion, a transient release of cytokines dominated by IL-10, IL-6, and IFN-γ was observed, which no longer occurred on start of a second treatment cycle. The response of lymphocytes in leukemic patients to continuous infusion of blinatumomab helps to better understand the mode of action of this and other globally T cell–engaging Abs. The trial is registered with www.clinicaltrials.gov identifier NCT00560794.
Type of Medium:
Online Resource
ISSN:
0006-4971
,
1528-0020
DOI:
10.1182/blood-2012-01-400515
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2012
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7