Development of GPC3 Targeting CAR-NK Cell with IL-15 Secretion for Treatment of Hepatocellular Carcinoma — ASN Events
  1. Schedule
  2. Poster Session Two
  3. Development of GPC3 Targeting CAR-NK Cell with IL-15 Secretion for Treatment of Hepatocellular Carcinoma

Development of GPC3 Targeting CAR-NK Cell with IL-15 Secretion for Treatment of Hepatocellular Carcinoma (#208)

Minji Park 1 , Ji Young Kim 1 , Hyeongbin Son 2 , Yujung Jo 1 , Soo Yun Lee 3 , Gamin Han 1 , Mijeong Lee 1 , Hyun-Young Kim 4 , Wonseok Kang 1 5 6 , Tae-Don Kim 3 , Yeup Yoon 1 2 6 , Duck Cho 1 2 4 7
  1. Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
  2. Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, Republic of Korea
  3. Center for Cell and Gene Therapy, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
  4. Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
  5. Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
  6. Institute for Future Medicine, Samsung Medical Center, Seoul, Republic of Korea
  7. Cell and Gene Therapy Institute (CGTI), Samsung Medical Center, Seoul, Republic of Korea

Hepatocellular carcinoma (HCC) accounts for 80% of liver cancers and remains a leading cause of cancer-related mortality. Glypican-3 (GPC3) has been identified as a promising target for immunotherapy due to its selective expression on HCC cells. Anti-GPC3 chimeric antigen receptor (CAR) immune therapies are currently under active investigation, with many clinical trials in progress. However, further optimization of the antigen-binding domain could be important for enhancing therapeutic efficacy. In this study, we engineered a novel GPC3 CAR-natural killer (NK) cells incorporating a high-affinity single-chain variable fragment (scFv) for enhanced tumor targeting. Furthermore, interleukin-15 (IL-15) was co-expressed in the CAR construct to improve NK cell persistence and sustained anti-tumor activity.

Using a synthetic Fab library and phage display panning, 13 anti-GPC3 scFv clones were identified, and two high-affinity scFv candidates (#54, #65) were selected for their strong binding to GPC3-positive HepG2 cells. CAR constructs (each GPC3 scFv-41BB-CD3ΞΆ) were designed, with or without expression of IL-15. CAR-NK92 cells were stably produced with comparable transduction efficiencies across all constructs.

Both scFv-based CAR-NK cells exhibited significant cytotoxicity against various HCC cell lines. Secretion of IL-15 was exclusively detected in GPC3-IL15 CAR-NK cells and promoted their prolonged survival under cytokine-deprived conditions, emphasizing the role of IL-15 in sustaining CAR-NK cell function. In a Hep3B subcutaneous tumor mouse model, intravenous administration of GPC3(#65)-IL15 CAR-NK cells resulted in significant tumor suppression and enhanced survival rates compared to IL-15-expressing NK cell controls. Notably, NK cell homing to tumor sites was exclusively observed in the GPC3-IL15 CAR-NK cell-treated group, indicating enhanced antigen-specific tumor targeting.

We successfully developed GPC3-targeting CAR-NK cells using our newly identified scFv sequences. Our scFv selection strategy and IL-15 co-expression significantly improved the GPC3-specific targeting and persistence of NK cell. This study advances CAR-NK cell therapy for HCC, offering a promising approach for improved therapeutic outcomes.