Article Text

Download PDFPDF

301 Preclinical development of AB-2100, a PSMA neovasculature-inducible CA9 CAR resistant to FASL and TGFb mediated suppression for the treatment of ccRCC
  1. Irene Scarfo1,
  2. Laura Lim1,
  3. Kevin Dang1,
  4. Marvin Chew1,
  5. Rakesh Sudhakah1,
  6. Michelle Nguyen1,
  7. Suchismita Mohanty1,
  8. Jeremy Chen1,
  9. Alma Gomez1,
  10. Nickolas Attanasio1,
  11. Amanda Fearon1,
  12. Ivan Chan2,
  13. Vibhavari Sail1,
  14. Thomas J Gardner1,
  15. Beatriz Millare1,
  16. James Zhang1,
  17. Darrian Moskowitz1,
  18. Vince Thomas1,
  19. Stanley Zhou1,
  20. Jenessa Smith1,
  21. Jennifer McDevitt1 and
  22. Angela Boroughs1
  1. 1Arsenal biosciences, South San Francisco, CA, USA
  2. 2 Nkarta Therapeutics, Redwood City, CA, USA
  • Journal for ImmunoTherapy of Cancer (JITC) preprint. The copyright holder for this preprint are the authors/funders, who have granted JITC permission to display the preprint. All rights reserved. No reuse allowed without permission.


Background Clinically effective CAR T cell therapy for solid tumors may require substantial T cell engineering to increase specificity and potency. We have developed AB-2100, an autologous, integrated circuit T (ICT) cell that encodes multiple synthetic ‘modules’ to overcome challenges in the treatment of clear cell renal cell carcinoma (ccRCC). AB-2100 includes a sequential ‘AND’ logic gate designed to limit off-tumor toxicity through dual tumor antigen recognition, a short hairpin ribonucleic acid-microRNA (shRNA-miR) module for the constitutive expression of shRNA-miRs for knockdown of FAS and TGFBR2, and a constitutive synthetic pathway activator (SPA) that drives constitutive STAT3 signaling for enhanced T cell cytotoxicity and expansion.

Methods On-target, off-tumor toxicity was previously observed with constitutive CA9 CAR T cell therapy. To overcome this, the AB-2100 sequential ‘AND’ logic gate consists of a priming receptor (PrimeR) specific for PSMA and an inducible CA9-targeted CAR that is expressed upon PrimeR engagement with PSMA on the tumor neovasculature of ccRCC. This unique feature of the logic gate increases the safety profile of AB-2100 given that PSMA and CA9 are not expressed in the same normal tissues. Dual-antigen specificity of the logic gate was assessed in vitro and in vivo via CA9+ and PSMA+CA9+-786-O tumors established on contralateral flanks. To model vascular priming, AB-2100 cells were co-cultured with PSMA-expressing endothelial HUVEC cells and K562-CA9 cells. An in vitro FAS cross-linking assay was conducted to assess the impact of FAS knockdown on FAS-mediated apoptosis. The enhanced anti-tumor activity conferred by TGFBR2 shRNA and SPA modules were assessed in a subcutaneous 786-O xenograft model. Lastly, AB-2100 potency was measured in a subcutaneous renal A498 xenograft tumor model.

Results In vitro cytotoxicity against single or dual antigen expressing tumor cell lines, as well as a dual flank xenograft model demonstrate that AB-2100 selectively kills tumors that express both CA9 and PSMA, and not tumors that express CA9 alone. Furthermore, we confirmed that AB-2100 was able to prime off of PSMA-expressing endothelial HUVEC cells and kill K562-CA9 tumor cells. Finally, AB-2100 containing shRNA-miR and SPA modules demonstrated enhanced anti-tumor activity in xenograft RCC models (786-O and A498).

Conclusions Preclinical data demonstrate that AB-2100 can selectively target antigens that cannot be safely targeted by conventional CARs, and overcome multiple suppressive mechanisms in the tumor microenvironment. These results support the evaluation of AB-2100 in the clinic for the treatment of advanced or metastatic ccRCC.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.