Pharmacy Resident University of Chicago Medical Center Chicago, Illinois, United States
Poster Abstract:
Background: Chimeric Antigen Receptor T-cell (CAR-T) therapy has revolutionized the treatment landscape for various hematological malignancies. However, it is associated with a range of hematologic complications, including severe and often prolonged thrombocytopenia. Currently, there are no known effective preventative measures against CAR-T-induced thrombocytopenia, and notably, there are no known effective therapies for managing CAR-T-induced thrombocytopenia. At the University of Chicago Medical Center, thrombopoietin receptor agonists (TPO-RAs) eltrombopag and romiplostim have been utilized intermittently, per attending preference, in CAR-T therapy patients presenting with prolonged thrombocytopenia following infusion. However, whether these treatments yield positive outcomes in this context remains uncertain. Prolonged thrombocytopenia is associated with increased morbidity and mortality in CAR-T patients, and currently, there is no standard approach to the utilization of TPO-RAs in this setting. This study provides a comparative evaluation of the effect of TPO-RAs on CAR-T-associated thrombocytopenia.
Objectives: To compare the incidence of platelet recovery (defined as two consecutive platelet counts of ≥ 50x10^9/L) in those who received TPO-RAs versus those who did not for CAR-T-associated prolonged thrombocytopenia. The secondary objectives include time to platelet recovery, incidence of clinically relevant bleed, length of stay, incidence of adverse effects associated with either romiplostim or eltrombopag, overall survival, and financial toxicity.
Methods: This study was an Institutional Review Board-approved, single-center, retrospective analysis of adult patients with hematologic malignancies treated with CAR-T therapy at a large academic medical center from January 1, 2018, to June 30, 2023, who experienced prolonged thrombocytopenia (defined as platelet counts of < 50x10^9/L for at least 14 days).
Results: Eighty-five patients with prolonged thrombocytopenia within one year of CAR-T administration were identified. Forty-four of these patients experienced severe thrombocytopenia (PLT < 20x10^9/L for at least 14 days). Twelve of these patients received TPO-RA therapy, while 73 were managed with supportive care. The median time to platelet recovery was 56 days in the TPO-RA-treated group and 41 days in those not managed with TPO-RAs. Statistical analysis and secondary objectives are pending and will be presented with the poster.
Conclusion: Conclusions are pending.
References (must also be included in final poster): 1. Drillet G, Lhomme F, De Guibert S, Manson G, Houot R. Prolonged thrombocytopenia after CAR T-cell therapy: the role of thrombopoietin receptor agonists. Blood Adv. 2023;7(4):537-540. doi:10.1182/bloodadvances.2022008066 2. Imbach P, Crowther M. Thrombopoietin-receptor agonists for primary immune thrombocytopenia. N Engl J Med. 2011;365(8):734-741. doi:10.1056/NEJMct1014202 3. Luo W, Li C, Zhang Y, et al. Adverse effects in hematologic malignancies treated with chimeric antigen receptor (CAR) T cell therapy: a systematic review and Meta-analysis. BMC Cancer. 2022;22(1):98. Published 2022 Jan 24. doi:10.1186/s12885-021-09102-x
