Shanghai Escugen Biotechnology Co., Ltd., a partner of Levena Biopharma, a Sorrento Company, releases positive results from a first-in-human study of ESG401, a TROP2 Antibody Drug Conjugate in patients with locally advanced/metastatic solid tumors at the

CHICAGO, June 05, 2023 (GLOBE NEWSWIRE) -- Shanghai Escugen Biotechnology Co., Ltd. (“Escugen”), a partner of Levena (Suzhou) Biopharma Co., Ltd. (“Levena”), a wholly owned subsidiary of Sorrento Therapeutics, Inc. (Sorrento), today released preliminary results from a first-in-human study of ESG401, a trophoblast cell-surface antigen 2 (TROP2) antibody drug conjugate (ADC), in patients with locally advanced/metastatic solid tumors at the 2023 Annual Meeting of ASCO, the American Society of Clinical Oncology, held June 2-6 in Chicago, IL. ESG401 is an innovative ADC developed by Escugen and Levena. Escugen and Levena Biopharma jointly own the domestic and international patents of this ADC and share global rights for the product. ESG401 is composed of a humanized anti-Trop2 IgG1 monoclonal antibody (mAb) conjugated to a topoisomerase I inhibitor SN38 via a proprietary stable covalent linker with a drug antibody ratio (DAR) of 8. ESG401 has potential differentiated advantages over its competitors in terms of safety, effectiveness and process robustness. Using an innovative, highly stable and cleavable linker, this ADC demonstrated that it releases very little free toxin during circulation, which may reduce off target toxicity in a series of preclinical studies. Additionally, premature release of the mAb may compete for binding sites with the ADC to reduce its efficacy. The ADC highly enriches in tumor tissues and rapidly endocytoses, thereby effectively killing tumor cells and inhibiting tumor growth.

In the Phase I study, adult ESG401 patients with locally advanced/metastatic solid tumors refractory to or relapsed from standard treatments with measurable disease (RECIST v1.1) were eligible. ESG401 was administered by IV infusion initially in an ascending dose safety study by designated dose and regimen until unacceptable toxicity or progressive disease and followed by expansion cohorts. The Bayesian Optimal Interval (BOIN) design was used to establish the maximum tolerated dose (MTD). As of February 3, 2023, 35 heavily pretreated patients with a median age of 53 years were treated with at least one dose of ESG401 during dose escalation, 2 to 20 mg/kg administered every 3 weeks (Regimen A), or 12 to 16 mg/kg on day 1, 8, and 15 in a 4-week cycle (Regimen B). Eighty percent of the patients had an ECOG status of 1. Sixty-three percent of the patients had received at least 3 lines of prior therapy and overall the number of lines of prior therapy was a median of 4 (range 2-10). A total of 94% of patients had visceral metastases (11% brain, 63% liver, 60% lung) at baseline. From the ASCO poster, patient demographics and baseline characteristics is shown below: