NY-303

In vivo, CYT-303 showed no toxicity or cytokine release in cynomolgus monkeys up to the highest dose (60 mg/kg), administered weekly by intravenous infusion for 28 days. These results demonstrate the potential of CYT-303 to be a safe and effective therapy against HCC.

CYT-303 efficacious doses identified in the HCC model together with safety in cynomolgus monkeys and planned human pharmacokinetic modeling studies support clinical evaluation of CYT-303 in first in human HCC clinical trials.

This work demonstrates that KI of IL-15 and KO of TGFβR2 is a promising strategy for TALEN®-engineered iNK cell therapies to overcome the immunosuppressive TME and mount a potent and persistent anti-tumor immune response. The data also provide a solid foundation for combining these edited iNK cells with CYT-303 to address the immunosuppressive TME towards a cure for HCC.

Conclusions Pharmacologically active CYT-303 doses were identified. CYT-303 can help recruit NK cells to the tumor site to achieve tumor growth inhibition.

CYT-303 greatly enhanced the cytotoxic activity of iNKs and cytolysis of Hep3B tumor cells in-vitro. CYT-303 and iNK cells, alone or in combination, demonstrate anti-tumor activity against HCC that warrants clinical development.