SCIENCE
& TECHNOLOGY

CONVERTER CAR

CONVERTER CAR platform with CTC28 technique

Tumor cells have strategies to avoid attack from the patient’s immune system. One of them is to strengthen the immune checkpoints such as CTLA-4 and PD-1/PD-L1. Thus, there are some efforts to combine CAR-T cell therapy and the immune checkpoint inhibitors. However, the immune checkpoint inhibitors activate all the T cells in patients including autoreactive T cells as well as tumor-specific T cells, which leads to autoimmune adverse side effects.

CONVERTER CAR technique of TiCARos enables selective inhibition of CTLA4 only in tumor-specific CAR-T cells without affecting other T cells in patient’s blood. CTLA4 has been known as a potent T cell inhibiting receptor. Thus, other CTLA4-inhibiting strategy such as neutralizing antibodies elicits strong autoimmune side effects. By selective inhibition of CTLA-4 only in CAR-T cells potentiates CAR-T activity without serious autoimmunity.

In the pre-clinical efficacy tests in mice, the CAR-T cells generated using CONVERTER CAR technique showed superior therapeutic efficacy over a commercialized 2nd generation CAR-T at the dosage where the commercialized CAR-T product shows unsatisfactory efficacy.

CTC28 T cell – Strengthened T cells
T cell activity is enhanced by replacing the intracellular inhibitory domain of CTLA4, an inhibitory immune checkpoint receptor, with the stimulatory domain of CD28, an immune-stimulating receptor. Thus, this technique converts a negative signal for T cells to a positive signal, resulting in T cell hyperactivation.