Poster Presentation 9th Australasian Vaccines & Immunotherapeutics Development Meeting 2022

Engineering a smarter class of Chimeric Antigen Receptor T cells (#101)

Rebecca C Abbott 1 2 , Daniel J Verdon 1 , Fiona M Gracey 3 , Hannah E Hughes-Parry 1 2 , Melinda Iliopoulos 1 , Kathy A Watson 1 , Matthias Mulazzani 1 , Kylie Luong 1 , Colleen D'Arcy 4 , Lucy C Sullivan 5 , Ben R Kiefel 3 , Ryan S Cross 1 , Misty R Jenkins 1 2 6
  1. Department of Immunology, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
  2. Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
  3. Myrio Therapeutics, Scoresby, Victoria, Australia
  4. Anatomical Pathology, Royal Children's Hospital, Parkville, Victoria, Australia
  5. Department of Microbiology and Immunology, Peter Doherty Institute, Parkville, Victoria, Australia
  6. Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia

Chimeric Antigen Receptor (CAR) T cells have demonstrated incredible effectiveness in treating some haematological malignancies1-3, and were recently shown to have the potential to provide long term remission4. However, clinical trial results in glioblastoma; a devastating form of brain cancer, have provided evidence that single agent CAR T therapy is insufficient to mediate long term tumour regression5, 6, attributed mostly to antigen escape, tumour heterogeneity and an immunosuppressive microenvironment. We have developed a novel antigen binding domain (ABD); GCT02 which binds to the glioblastoma-specific mutation EGFRvIII7. The GCT02 CAR was found to secrete generally lower quantities of cytokines compared to a CAR generated with the 2173-EGFRvIII ABD (UPenn/Novartis5) but maintained cytotoxic capacity. In vivo, this CAR mediated the complete and rapid clearance of murine orthotopic brain tumours7.

 

However, as these single target approaches have shown vulnerability to antigen escape particularly for heterogeneous tumours, smarter engineering of T cells is likely going to be required to enhance overall efficacy. Logic gating technology is one such form of enhanced engineering, allowing delivery of anti-tumour molecules directly into the tumour. Using the Synthetic Notch (SynNotch) AND-gating system8-10, we designed receptors using the GCT02 and 2173 ABDs, and have shown these receptors to be functional in triggering the transcription of a proinflammatory cytokine.

 

I will also present pilot data which may suggest that factors such as affinity, avidity and ABD which are all known to influence CAR function, may also play a role in influencing SynNotch function.

 

In summary, we have developed a functional and effective novel CAR, specific for EGFRvIII and repurposed the ABD to a logic gated system. SynNotch circuits may enhance safety via localised mediator release and provides the potential for combination therapies to be delivered at the tumour site, thus enhancing therapeutic efficacy in glioblastoma.

  1. Maude SL, Frey N, Shaw PA, Aplenc R, Barrett DM, Bunin NJ, Chew A, Gonzalez VE, Zheng Z, Lacey SF et al. (2014) Chimeric Antigen Receptor T Cells for Sustained Remissions in Leukemia. New England Journal of Medicine. 371(16):1507-1517.
  2. Brentjens RJ, Davila ML, Riviere I, Park J, Wang X, Cowell LG, Bartido S, Stefanski J, Taylor C, Olszewska M et al. (2013) CD19-targeted T cells rapidly induce molecular remissions in adults with chemotherapy-refractory acute lymphoblastic leukemia. Science translational medicine. 5(177):177ra138-177ra138.
  3. Park JH, Rivière I, Gonen M, Wang X, Sénéchal B, Curran KJ, Sauter C, Wang Y, Santomasso B, Mead E et al. (2018) Long-Term Follow-up of CD19 CAR Therapy in Acute Lymphoblastic Leukemia. New England Journal of Medicine. 378(5):449-459.
  4. Melenhorst JJ, Chen GM, Wang M, Porter DL, Chen C, Collins MA, Gao P, Bandyopadhyay S, Sun H, Zhao Z et al. (2022) Decade-long leukaemia remissions with persistence of CD4+ CAR T cells. Nature. 602(7897):503-509.
  5. O'Rourke DM, Nasrallah MP, Desai A, Melenhorst JJ, Mansfield K, Morrissette JJD, Martinez-Lage M, Brem S, Maloney E, Shen A et al. (2017) A single dose of peripherally infused EGFRvIII-directed CAR T cells mediates antigen loss and induces adaptive resistance in patients with recurrent glioblastoma. Science translational medicine. 9(399).
  6. Goff SL, Morgan RA, Yang JC, Sherry RM, Robbins PF, Restifo NP, Feldman SA, Lu YC, Lu L, Zheng Z et al. (2019) Pilot Trial of Adoptive Transfer of Chimeric Antigen Receptor-transduced T Cells Targeting EGFRvIII in Patients With Glioblastoma. J Immunother. 42(4):126-135.
  7. Abbott RC, Verdon DJ, Gracey FM, Hughes-Parry HE, Iliopoulos M, Watson KA, Mulazzani M, Luong K, D'Arcy C, Sullivan LC et al. (2021) Novel high-affinity EGFRvIII-specific chimeric antigen receptor T cells effectively eliminate human glioblastoma. Clin Transl Immunology. 10(5):e1283.
  8. Morsut L, Roybal Kole T, Xiong X, Gordley Russell M, Coyle Scott M, Thomson M, Lim Wendell A. (2016) Engineering Customized Cell Sensing and Response Behaviors Using Synthetic Notch Receptors. Cell. 164(4):780-791.
  9. Roybal Kole T, Rupp Levi J, Morsut L, Walker Whitney J, McNally Krista A, Park Jason S, Lim Wendell A. (2016) Precision Tumor Recognition by T Cells With Combinatorial Antigen-Sensing Circuits. Cell. 164(4):770-779.
  10. Roybal KT, Williams JZ, Morsut L, Rupp LJ, Kolinko I, Choe JH, Walker WJ, McNally KA, Lim WA. (2016) Engineering T Cells with Customized Therapeutic Response Programs Using Synthetic Notch Receptors. Cell. 167(2):419-432.e416.