denotes an abstract that is clinically relevant.
denotes that this is a recommended PHD Trainee Session.
denotes that this is a ticketed session.Session: 704. Cellular Immunotherapies: Early Phase Clinical Trials and Toxicities: Poster I
Hematology Disease Topics & Pathways:
Research, Clinical trials, Acute Myeloid Malignancies, AML, Adult, Clinical Research, Chimeric Antigen Receptor (CAR)-T Cell Therapies, Diseases, Treatment Considerations, Biological therapies, Myeloid Malignancies, Study Population, Human
Approximately 10-20% of patients diagnosed with acute myeloid leukemia (AML) present with extramedullary diseases (EMDs), which exhibit a significantly distinct etiology, therapeutic response, and prognosis compared to AML patients without EMDs. The proportion of patients with EMDs further increases in those with refractory and relapsed AML. The objective of this study is to evaluate potential disparities in the efficacy and adverse effects of Chimeric Antigen Receptor T-cell therapy (CAR-T) therapy targeting CLL1 between patients with and without EMDs.
Methods
A total of 47 patients, including 20 patients with EMDs, were prospectively enrolled in this prospective study, which has obtained approval from the institutional review board of Tianjin First Center Hospital and has been duly registered with the China Clinical Trial Registration Center (Clinical Trial Number: ChiCTR2000041054). All patients underwent lymphodepletion chemotherapy with a 3-day regimen of fludarabine (25 mg/m2) and cyclophosphamide (300 mg/m2) prior to the infusion of CAR-T cells. Afterwards, we thoroughly evaluated the effectiveness and occurrence of side effects during the treatment process, while also comparing the differences in laboratory indicators between patients with and without EMDs.
Results
Among the 20 patients with EMDs and the 27 individuals without EMDs, complete remission was achieved by 65.00% and 81.48% of patients, respectively, resulting in long-term survival through subsequent hematopoietic stem cell transplantation. Although the overall survival, progression-free survival, and duration of remission period appeared to be shorter for patients with EMDs compared to those without EMDs, this difference did not reach statistical significance. The incidence rates of complications, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and hematological toxicities, were similar in both groups. Meanwhile, there were no significant differences observed in the levels of CAR-T cell proliferation and accompanying cytokines release between patients with and without EMDs.
Conclusion
The results of our study have demonstrated the efficacy of CLL1 CAR-T therapy in the treatment of AML patients with EMDs. Despite a high incidence of CRS, ICANS, and hematological side effects, most patients were effectively managed through systemic treatment and subsequent bridged HSCT. Therefore, we recommend CLL1 CAR-T therapy as an efficient and safe therapeutic option for AML patients, irrespective of the presence of EMDs.
Disclosures: No relevant conflicts of interest to declare.
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