Patients with relapsed or refractory CD 19+ leukemia who have achieved remission after CD19 CAR-T cell treatment sometimes relapse because the CD 19 CAR-T cells decrease in number over time. Study PLAT-03 will test whether administering T cell antigen presenting cells (T-APCs) at intervals following treatment with CAR-T cells improves CD 19 CAR-T cell persistence and reduces the incidence of leukemia relapse.
This pilot study seeks to examine the feasibility and safety of administering T cell antigen presenting cells (T-APCs) designed to reactivate and numerically expand CD19-specific CAR T cells. The underlying hypothesis to be examined is that after remission is achieved with CAR T cell treatment, the duration, magnitude, and activation state of persisting memory CAR T cells impact on the potential for durable leukemia eradication. This is of particular relevance in two groups of patients we have identified: those who are predicted to lose persistence of their CAR T cells before Day 63, and those who have definitively lost persistence of CAR T cells prior to 6 months. By providing these patients with episodic exposure to T-APCs capable of activating CD19-specific CAR T cells for proliferation and redistribution to tissue beds where tumor cells of ALL seed, ideally over several months following remission induction, it is posited that the incidence of disease relapse will be diminished.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Autologous CD4 and CD8 T cells transduced to express a truncated CD19 (CD19t) Transgene
Seattle Children's Hospital
Seattle, Washington, United States
The adverse events associated with one or multiple CD19t T-APC product infusions will be assessed.
Type, frequency, severity, and duration of adverse events will be summarized
Time frame: up to 6 months
Determine the feasibility of deriving and administering a CD19t T-APC product
Proportion of products successfully manufactured and infused
Time frame: 28 days
Quantification of changes in the number of CAR T cells in peripheral blood before and after receiving CD19t T-APCs
Multiparameter Flow Cytometry (MPF) from peripheral blood as a measure of magnitude and presence of CAR T cells before and after a dose of T-APCs
Time frame: 6 months
Duration of B cell aplasia in CD19t T-APC treated patients
MPF from peripheral blood as a measure of B cell aplasia
Time frame: up to 5 years
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.