Achievement of disease control with dasatinib after CAR T-cell therapy for relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia: a case report and literature review

Historically, treatment outcomes for patients with Philadelphia-positive chromosome (Ph+) acute lymphoblastic leukemia (ALL) have been extremely poor. The introduction of tyrosine kinase inhibitor (TKI) and chimeric antigen receptor-engineered T (CAR T)-cell therapy mark crucial advancements in the treatment of Ph+ALL. In this case, we investigated a 42-year-old woman who was diagnosed with Ph+ALL and experienced multiple relapses. She was first treated with imatinib combined infusion chemotherapy and achieved complete remission (CR). She stayed disease free for 13 months until later diagnosed with central nervous system lymphoma (CNSL). Subsequently, she was treated with intrathecal injection, multi-agent chemotherapy along with dasatinib at 140 mg/d. Despite her initial recovery, she experienced her second relapse at a later stage during the infusion chemotherapy. She then received CAR T-cell therapy and responded well until a third relapse occurred 10 months later. She was again administered dasatinib at 140 mg/d and ever since then, no recurrence in peripheral blood, BM or CNS was observed. We suspect that a synergistic effect between CAR T-cell therapy and TKI exists in the treatment of Ph+ALL. Furthermore, we hypothesize that dasatinib may have in some way stimulated CAR T-cells proliferation in vivo, thereby restoring their function.