6 May 2022 - - China-based biopharmaceutical company Elpiscience Biopharmaceuticals, Inc's partner Compass Therapeutics reported positive interim ES104 (also known as CTX-009) Phase 2 data in combination with paclitaxel in patients with biliary tract cancers, the company said.

ES104 is a bispecific antibody that simultaneously blocks Delta-like ligand 4/Notch and vascular endothelial growth factor A (VEGF-A) signaling pathways, which are critical to angiogenesis and tumor vascularization.

In the study, ES104 demonstrated a 42% overall response rate based on 10 patients with Partial Responses, including 9 PRs confirmed by RECIST 1.1 and 1 PR pending confirmation.

It demonstrated anti-tumor activity in previously treated patients with a clinical benefit rate of 92% based on 22 patients with a PR or stable disease out of 24 enrolled patients.

The drug was well-tolerated and preliminary safety profile consistent with prior studies, the study found.

The Phase 2 study in patients with BTC is currently being conducted at four leading medical centers in Korea and Compass Therapeutics plans to open additional sites in the United States.

In China, Elpiscience is currently enrolling patients in a ES104 Phase 1/2 study for the treatment of unresectable locally advanced or metastatic colorectal cancer. ES104 is currently the only clinical-stage bispecific antibody targeting VEGF and DLL4 in China.

ES104 is a bispecific antibody that simultaneously blocks Delta-like ligand 4/Notch and vascular endothelial growth factor A (VEGF-A) signaling pathways, which are critical to angiogenesis and tumor vascularization.

Pre-clinical and early clinical data of ES104 show that blocking both pathways provides robust anti-tumor activity across several solid tumors, including colorectal, gastric, cholangiocarcinoma, pancreatic, and non-small cell lung cancer.

Partial responses to ES104 as monotherapy have been observed in heavily pre-treated cancer patients, who were resistant to currently approved anti-VEGF therapies.

ES104 has completed a Phase 1 monotherapy dose-escalation and expansion study (NCT03292783). Phase 1b and Phase 2 clinical studies (NCT04492033) in combination with chemotherapy are ongoing.

Elpiscience licensed ES104 greater China rights from Compass Therapeutics in January 2021 and is conducting Phase 1/2 study in China for treatment in patients with unresectable locally advanced or metastatic colorectal cancer.

Elpiscience is a clinical-stage biopharmaceutical company focused on developing next-generation immunotherapy to benefit cancer patients worldwide.

The company has a pipeline of cancer immunotherapies covering wide range of oncology targets and multiple proprietary technologies to enable discovery including its Bispecific Macrophage Engager (BiME) antibody platform for solid tumors.