CAR T cell therapy for relapsed or refractory AML

Reference: August 2026 | Issue 8 | Vol 12 | Page 40

Anti-CD7 CAR T cell therapy demonstrates rapid and deep MRD-negative remission in a subset of patients with relapsed or refractory acute myeloid leukaemia (R/R AML), according to a poster presentation at the European Hematology Association Congress 2026.

The study included 11 with CD7-positive (≥70% by flow cytometry) R/R AML patients treated at Beijing Boren Hospital between August 2023 and August 2025. The median age was 35 years, with an age range of 10 to 65. Six patients (54.5 per cent) had extramedullary disease.

Patients had received a median of three prior lines of therapy, with a maximum of eight previous lines. Six (54.5 per cent) had previously undergone allogeneic haematopoietic stem cell transplantation (HSCT), including one patient with two prior transplants.

Patients received lympho-depleting chemotherapy with fludarabine and cyclophosphamide prior to CAR T cell infusion. Clinical responses, minimal residual disease (MRD), adverse events, and CAR T cell expansion were assessed according to standard criteria.

At day 14 post-infusion, six of the 11 patients (54.6 per cent) achieved confirmed remission, including five patients with MRD-negative complete remission (CR) with incomplete haematologic recovery (CRi) and one patient with MRD-negative CR.

Bone marrow MRD negativity was observed in an additional patient with prior double HSCT and extramedullary disease; however, extramedullary lesions could not be evaluated due to early death from grade 4 immune effector cell-associated neurotoxicity syndrome (ICANS), and this patient was not considered fully evaluable for overall response.

Four patients showed no response, including one patient without detectable CAR T cell expansion and three patients who exhibited loss of CD7 expression on leukaemic blasts, suggesting antigen escape as a mechanism of resistance.

With a median follow-up of 129 days, five responding patients proceeded to consolidation allogeneic HSCT and all maintained MRD-negative remission at last follow-up. One patient who achieved MRD-negative CR but did not undergo HSCT remained in continuous remission with maintenance therapy.

Among non-responders, all underwent salvage HSCT; two achieved MRD-negative CR, while two died from post-transplant infectious complications. Cytokine release syndrome (CRS) occurred in 10 patients, including grade 3 CRS in two patients and grade 4 CRS in one patient. One patient developed fatal grade 4 ICANS. The most common grade ≥3 adverse events were haematologic toxicities.

CAR T cell expansion peaked at a median of 14.5 days post-infusion.

Inflammatory biomarker dynamics differed between patients with and without CAR T cell expansion.

R/R AML continues to have poor clinical outcomes, and no standard salvage therapy has been established. CD7-directed CAR T cell therapy has shown promising activity in other CD7-positive T cell malignancies, however, clinical evidence in R/R AML remains limited. This study adds to the evidence base on CAR T cell therapy in this patient population.

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