CBT Pharmaceuticals’ PD-L1 Antibody Shows Promising Anti-Tumor Activity in Preclinical Studies

CBT Pharmaceuticals’ PD-L1 Antibody Shows Promising Anti-Tumor Activity in Preclinical Studies

CBT Pharmaceuticals‘ anti-PD-L1 antibody CBT-502 has shown promising immune activation and inhibition of tumor growth in preclinical models of cancer, according to new preclinical data.

The data were presented in a poster titled, “CBT-502 (TQB2450), a novel anti-PD-L1 antibody, demonstrates favorable activity in MC-38/H-11 murine colon and A375 human melanoma animal models,” at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Philadelphia.

Studies showed that this new drug candidate stimulates the production of the cytokines interleukin-2 (IL-2) and interferon gamma (IFN-gamma), leading to suppression of tumor growth in models of colon cancer and melanoma. It produced these results with a similar effectiveness as Tecentriq (atezolizumab), another PD-L1 inhibitor.

“The in-vitro characteristics and in-vivo efficacy studies showing linear pharmacokinetics suggest that CBT-502 may provide benefit in a variety of tumor types,” Sanjeev Redkar, PhD, president and chief executive officer at CBT, said in a press release.

Redkar added that compared to other PD-L1 blockers on the market today, CBT-502’s molecular composition “may offer a point of differentiation in the clinical setting.”

Several cancer cell types present high levels of PD-1, the receptor of PD-L1. The binding of PD-L1 to PD-1 inhibits activated T-cells (a type of immune cell), which are crucial in killing tumor cells. Therefore, the therapeutic blocking of PD-L1 reduces tumor growth by stimulating the activity of T-cells.

The research showed that CBT-502 efficiently and specifically inhibited the binding of PD-L1. Furthermore, the researchers observed an increased release of IL-2 and IFN-gamma, which proved that CBT-502 augmented human T-cell activation.

Importantly, in mouse models of human melanoma and colon adenocarcinoma, CBT-502 significantly inhibited tumor growth in a dose-dependent manner. This effect was comparable to Genentech’s Tecentriq.

Additionally, pharmacology and toxicology data of CBT-502 showed effective activity with a wide margin of safety.

“These studies support our commitment to advancing the clinical development of CBT-502 as an immuno-oncology therapy for a variety of cancers,” said Gavin Choy, executive vice president and chief operating officer at CBT.

Investigational new drug studies, which facilitate clinical research, “will commence in 2018 and a phase 1/2 combination study will be initiated in the second half of 2018 in Australia,” he added. 

CBT-502 is being developed by Chia Tai Tianqing (CTTQ) Pharmaceutical Group for commercialization in China. CBT has marketing rights for the rest of the world.