First-in-Human Trial of EphA2-Redirected CAR T-Cells in Patients With Recurrent Glioblastoma: A Preliminary Report of Three Cases at the Starting Dose

Abstract

Glioblastoma is the most common primary brain malignancy with limited treatment options. EphA2 is a tumor-associated-antigen overexpressed in glioblastoma. Pre-clinical studies have demonstrated the promise of EphA2-redirected CAR T-cells against glioblastoma. We conduct the first-in-human trial of EphA2-redirected CAR T-cells in patients with EphA2-positive recurrent glioblastoma and report the results of three patients enrolled as the first cohort receiving the starting dosage (1×106 cells/kg). A single infusion of EphA2-redirected CAR T-cells was administrated intravenously, with the lymphodepletion regimen consisting of fludarabine and Cyclophosphamide. In two patients, there was grade 2 cytokine release syndrome accompanied by pulmonary edema, which resolved completely with dexamethasone medication. Except that, there was no other organ toxicity including neurotoxicity. In both the peripheral blood and cerebral-spinal-fluid, we observed the expansion of CAR T-cells which persisted for more than four weeks. In one patient, there was a transit diminishment of the tumor. Among these three patients, one patient reported SD and two patients reported PD, with overall survival ranging from 86 to 181 days. At the tested dose level (1×106 cells/kg), intravenously infusion of EphA2-rediretected CAR T-cells were preliminary tolerable with transient clinical efficacy. Future study with adjusted dose and infusion frequency of CAR T-cells is warranted.

Trial registration numbers: NCT03423992.

Keywords: EphA2; chimeric antigen receptor (CAR T); clinical trial; glioma; immunotherapy.

Conflict of interest statement

JH and JL were employed by Hebei Senlang Biotechnology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2021 Lin, Ba, Ho, Chen, Cheng, Wang, Xu, Xu, Zhou, Wei, Li and Ling.

Figures

Figure 1

Schema of EphA2-CAR vector and study protocol. (A) Sequence diagram of humanized anti-EphA2 CAR vector. EphA2 scFv, humanized anti-EphA2 single-chain fragment variable; tEGFR, truncated epidermal growth factor receptor. (B) Study protocol diagram. Flu, Fludarabine; Cy, Cyclophosphamide.

Figure 2

IHC staining of the tumor and clinical response in patient 1. (A) Anti-EphA2 IHC staining of tumor tissue before enrollment. (B) Thoracic X-ray performed on days 10, 14, 21, after the infusion of CAR T-cells, showing the development and resolution of pulmonary edema in the right superior and middle lobes. (C) Dynamic changes of critical cytokines in the peripheral blood along with temperature, after the infusion of CAR T-cells. The dotted green line on the x-axis indicating the time window for the use of dexamethasone. (D) Expansion of CAR T-cells in the peripheral blood by flow cytometry (left y-axis) and qPCR (right y-axis). (E) Contrast-enhanced MRI performed before and after (8 and 12 weeks) the infusion of CAR T-cells.

Figure 3

IHC staining of the tumor and clinical response in patient 2. (A) Anti-EphA2 IHC staining of tumor tissue before enrollment. (B) Expansion of CAR T-cells in the peripheral blood by flow cytometry (left y-axis) and qPCR (right y-axis). (C) Dynamic changes of critical cytokines in the peripheral blood along with temperature, after the infusion of CAR T-cells. (D) Contrast-enhanced brain MRI performed before and 4 weeks,12 weeks after the infusion of CAR T-cells.

Figure 4

IHC staining of the tumor and clinical response in patient 3. (A) Anti-EphA2 IHC staining of tumor tissue before enrollment. (B) Dynamic changes of critical cytokines in the peripheral blood along with temperature, after the infusion of CAR T-cells. The dotted green line on the x-axis indicating the time window for the use of dexamethasone. (C) Thoracic X-ray performed on days 6 and 21 after the infusion of CAR T-cells, showing the development and resolution of pulmonary edema in the right middle and inferior lobes. (D) Expansion of CAR T-cells in the peripheral blood by flow cytometry (left y-axis) and qPCR (right y-axis). (E) Contrast-enhanced MRI performed before and after (4 and 8 weeks) the infusion of CAR T-cells.