CAR-T therapy has evolved as a pivotal treatment for relapsed/refractory (R/R) leukemia, demonstrating improved remission rates and manageable adverse events. However, over 50% of patients achieving complete remission (CR) experience relapse within one year (1-year cumulative incidence rate, CIR) due to antigen escape, CAR-T functional exhaustion, premature cell depletion, and immunosuppressive microenvironments. Novel strategies are urgently needed to sustain durable responses.
Bridging CAR-T therapy with TCRαβ+ and CD45RA+ cell-depleted haploidentical hematopoietic stem cell transplantation (HSCT) offers dual benefits: Graft-versus-leukemia (GvL) effects mediated by donor-derived NK cells and γδT cells target non-CAR-dependent antigens, mitigating immune evasion. Rapid hematopoietic reconstitution reduces prolonged cytopenia-related complications from prior therapies. This protocol further incorporates prophylactic CD45RO+ memory T-cell (Tm) infusion to: Minimize graft-versus-host disease (GVHD) risks compared to conventional donor lymphocyte infusion (DLI). Enhance adoptive immunity against infections/relapse via transferred donor memory immunity. We design this prospective, single-center, single-arm trial to evaluate the efficacy/safety of this approach using the CliniMACS® system for ex vivo TCRαβ+/CD45RA+ depletion in R/R leukemia patients post-CAR-T.
Diagnosis: Patients with refractory or relapsed (R/R) leukemia.
Donor Availability: No matched sibling or unrelated donor identified through HLA typing.
Disease Status Post-CAR-T: including achieved complete remission (CR), minimal residual disease (MRD)-negative in bone marrow and no extramedullary relapse.
Normal Organ Function (meeting the following criteria): including liver function: ALT/AST ≤10×ULN (upper limit of normal), total bilirubin (TBIL) ≤5×ULN, renal function: BUN and serum creatinine (Cr) ≤1.25×ULN and cardiac function: No evidence of cardiac insufficiency (confirmed by ECG and echocardiography).
Presence of any absolute contraindication to hematopoietic stem cell transplantation.
Severe Comorbidities with Major Organ Dysfunction
Ruijin Hospital
Lead sponsor
Miltenyi Biotec B.V. & Co. KG
Collaborator