We’re pleased to share an exciting update from our blood cancer study presented at this year’s European Society for Blood and Marrow Transplantation (EBMT) in Paris this month.

The CARPALL study is aimed at treating children and young adults with a type of blood cancer called Acute Lymphoblastic Leukaemia (ALL), which has either returned after treatment, or is likely to return. This is done with CAR T-cell therapy. The therapy involves collecting some of a patient's immune cells, called T-cells, altering them in a lab so they can specifically recognise and fight the cancer cells in the blood, and then putting them back in the patient's body. 

Previously, we reported how patients were treated with CAR T-cell therapy which targeted a specific CD19 protein located on leukaemia cells [1]. However, in some patients, the cancer cells mutated to escape recognition by the CAR T-cells, resulting in the patient’s cancer returning or relapsing. To prevent this, we further modified the CAR T-cells to also recognise CD22 protein in addition to CD19. Dual targeting of both CD19/22 proteins may reduce the leukaemia’s ability to escape recognition from the CAR T-cells, preventing the disease from returning.

The latest data from the study, presented at EBMT by Dr Giovanna Lucchini from Great Ormond Street Hospital, London, showed that the CD19/22 CAR T-cells were well tolerated, with no cases of severe cytokine release syndrome (a common immune reaction to this type of therapy). Complete remission with no minimal residual disease (MRD) was achieved in 83% (10 of 12) of patients and median duration of remission was 9.9 months.

Dr Lucchini remarked: ‘The update results of the CARPALL study have been shared with the scientific community during the 49th European Bone Marrow Transplant general congress. The data were reported as an oral presentation during a scientific session dedicated to innovative CAR T-cell products, and the data have been met with interest by the international audience.’

Key points from the presentation also include:

• Twelve patients with advanced paediatric ALL were treated in a study. The median age was 12 years.
• Good safety profile of the CD19/22 CAR T cells with no cases of severe cytokine release syndrome.
• The CD19/22 CAR T cells induced MRD negative complete remission (CR) in 83% (10 of 12) of patients. This includes 2 (of 3) patients who had CD19 negative disease, demonstrating the efficacy of the CD22 CAR.
• Disease remissions were induced despite the high-risk nature of this patient group.
• There has been no antigen negative relapse seen in responding patients to date.

These latest results from the CARPALL study are promising and bring us one step closer to helping fight this disease.