Non-response and disease relapse
When a patient is able to be treated at an institution that offers tisagenlecleucel, another challenge lies in the failure for them to either achieve remission or to maintain a sustained remission. Although tisagenlecleucel has the potential to be definitive therapy for patients with r/r B-ALL who achieve long-term CAR T cell persistence, approximately 10-20% of patients fail to enter remission after receiving anti-CD19 CAR T cell therapy, and 30-50% of patients who achieve remission will have either antigen-positive or -negative disease relapse, the majority within 1 year of infusion21,51,54. Specifically, in the ELIANA trial, 38% of patients who initially achieved a CR after CAR T cell infusion when on to relapse within 24 months 22 21. Of those 19 patients who relapsed in that timeframe, 14 (74%) showed evidence of CD19 escape. Other institutions across the country have also reported similar antigen negative relapse rates with other CD19 CAR T cell constructs 47,51,55,56.