Article
Author: Dey, Aonkon ; Cook, Daniella T. ; Wiggin, Hadley R. ; Berger, Trisha R. ; Horick, Nora K. ; Elder, Eva L. ; Schmidts, Andrea ; Leick, Mark B. ; Graham, Charlotte E. ; Katsis, Katelin ; Daley, Heather ; Ritz, Jerome ; Armant, Myriam ; Nikiforow, Sarah ; Lee, Won-Ho ; DiPersio, John F. ; Dolaher, Maria A. ; Nardi, Valentina ; Gallagher, Kathleen M. E. ; Preffer, Fred ; Wehrli, Marc ; Frigault, Matthew J. ; Scarfò, Irene ; Chen, Yi-Bin ; El-Jawahri, Areej ; Huang, Lu ; Bouffard, Amanda ; Maus, Marcela V. ; Parker, Aiyana L. ; Ritchey, Julie ; Haradhvala, Nicholas J. ; Chekmasova, Alena A.
AbstractWe report a first-in-human clinical trial using chimeric antigen receptor (CAR) T cells targeting CD37, an antigen highly expressed in B- and T-cell malignancies. Five patients with relapsed or refractory CD37+ lymphoid malignancies were enrolled and infused with autologous CAR-37 T cells. CAR-37 T cells expanded in the peripheral blood of all patients and, at peak, comprised >94% of the total lymphocytes in 4 of 5 patients. Tumor responses were observed in 4 of 5 patients with 3 complete responses, 1 mixed response, and 1 patient whose disease progressed rapidly and with relative loss of CD37 expression. Three patients experienced prolonged and severe pancytopenia, and in 2 of these patients, efforts to ablate CAR-37 T cells, which were engineered to coexpress truncated epidermal growth factor receptor, with cetuximab were unsuccessful. Hematopoiesis was restored in these 2 patients after allogeneic hematopoietic stem cell transplantation. No other severe, nonhematopoietic toxicities occurred. We investigated the mechanisms of profound pancytopenia and did not observe activation of CAR-37 T cells in response to hematopoietic stem cells in vitro or hematotoxicity in humanized models. Patients with pancytopenia had sustained high levels of interleukin-18 (IL-18) with low levels of IL-18 binding protein in their peripheral blood. IL-18 levels were significantly higher in CAR-37–treated patients than in both cytopenic and noncytopenic cohorts of CAR-19–treated patients. In conclusion, CAR-37 T cells exhibited antitumor activity, with significant CAR expansion and cytokine production. CAR-37 T cells may be an effective therapy in hematologic malignancies as a bridge to hematopoietic stem cell transplant. This trial was registered at www.ClinicalTrials.gov as #NCT04136275.