Preclinical assessment of the efficacy and specificity of GD2-B7H3 SynNotch CAR-T in metastatic neuroblastoma

Babak Moghimi,Sakunthala Muthugounder,Hiroyuki Shimada,Shahab Asgharzadeh,Samy Jambon,Rachelle Tibbetts,Michael D Hogarty,Long Hung,Hamid Bassiri,David M Barrett

doi:10.1038/s41467-020-20785-x

Abstract

The ability to utilize preclinical models to predict the clinical toxicity of chimeric antigen receptor (CAR) T cells in solid tumors is tenuous, thereby necessitating the development and evaluation of gated systems. Here we found that murine GD2 CAR-T cells, specific for the tumor-associated antigen GD2, induce fatal neurotoxicity in a costimulatory domain-dependent manner. Meanwhile, human B7H3 CAR-T cells exhibit efficacy in preclinical models of neuroblastoma. Seeking a better CAR, we generated a SynNotch gated CAR-T, GD2-B7H3, recognizing GD2 as the gate and B7H3 as the target. GD2-B7H3 CAR-T cells control the growth of neuroblastoma in vitro and in metastatic xenograft mouse models, with high specificity and efficacy. These improvements come partly from the better metabolic fitness of GD2-B7H3 CAR-T cells, as evidenced by their naïve T-like post-cytotoxicity oxidative metabolism and lower exhaustion profile.

Highlights

The ability to utilize preclinical models to predict the clinical toxicity of chimeric antigen receptor (CAR) T cells in solid tumors is tenuous, thereby necessitating the development and evaluation of gated systems
Animals treated with murine GD2 (mGD2)-28z CAR showed signs of reduced tumor burden before succumbing to neurotoxicity, while those treated with mGD2-BBz CAR had no evidence of neurotoxicity and minimal anti-tumor efficacy, with only 1 out of 11 mice showing a decrease in tumor signal (Fig. 1a and 2a)
Surviving mice were followed for a minimum of 100 days post-tumor inoculation. h Representative images from immunohistochemical analysis of liver tissue obtained from mice injected i.v. with 1 × CHLA255 followed by i.v. injection of 1 × untransduced T cells (UT) cells or 1 × 107 B7H3 CAR-T cells on day 28

Summary

Introduction

The ability to utilize preclinical models to predict the clinical toxicity of chimeric antigen receptor (CAR) T cells in solid tumors is tenuous, thereby necessitating the development and evaluation of gated systems. GD2-B7H3 CAR-T cells control the growth of neuroblastoma in vitro and in metastatic xenograft mouse models, with high specificity and efficacy These improvements come partly from the better metabolic fitness of GD2-B7H3 CAR-T cells, as evidenced by their naïve T-like post-cytotoxicity oxidative metabolism and lower exhaustion profile. A novel approach using synthetic Notch (SynNotch) design was recently described as a gating strategy where expression of a CAR for one TAA is dependent on initiation of a transactivating signal by another TAA9,10. This approach fuses a single-chain variable fragment (scFv) directed against a TAA to a SynNotch receptor, creating the gate. We hypothesize that a SynNotch-gated strategy could generate specific and efficacious CAR-T cells against neuroblastoma (NBL), a common solid tumor of childhood. We hypothesize that the intermittent gate-dependent expression of the second CAR in this design will lead to less tonic signaling resulting in less T-cell exhaustion and improved metabolic fitness

Methods

Results

Conclusion