Researchers at the City of Hope cancer research centre are developing a chimeric antigen receptor (CAR) T-cell therapy for the treatment of relapsed blood cancers.

The therapy is designed to target a cancer-related protein called B cell-activating factor receptor (BAFF-R). It is intended to help treat patients who relapse after first-line CD19 CAR T-cell therapy.

Statistics show that approximately 20-30% of leukaemia and lymphoma patients with remission after CD19 CAR T therapy experience relapse after a few years.

City of Hope comprehensive cancer centre vice-president and deputy director Larry Kwak said: “One major obstacle to current CAR T therapy is that in up to a third of these patients, the tumour is actually smart and comes back because it has learned how to no longer express the target that’s recognised by the original immunotherapy.

“To combat that, City of Hope research has found a new, and potentially more effective, target for CAR T-cell therapy against B cell leukaemia’s and lymphomas. We plan to open a clinical trial next year using the BAFF-R CAR T cell therapy.”

In CAR T-cell therapy, patients’ T-cells from the bloodstream are genetically engineered to identify and attack a specific cancer protein after reintroduction into the blood.

Upon testing BAFF-R CAR T therapy in animal models with CD19 therapy-resistant human leukaemia and lymphoma tumours, results showed tumour regression and prolonged survival.

Moreover, models with human Burkitt lymphoma showed complete tumour regression and 100% long-term survival when treated with the therapy, said City of Hope.

In models with a mixed population of CD19-positive and negative tumours, the BAFF-R CAR T therapy eradicated both types of tumours, while CD19 CAR T cells failed to demonstrate the same effect.

Researchers intend to launch a clinical trial next year to assess the BAFF-R CAR T cell therapy in patients with B cell leukaemia and lymphoma who have relapsed after CD19 CAR T cell therapies or blinatumomab.

City of Hope licensed the BAFF-R CAR T therapy to PeproMene Bio.