NextCure, Inc. has announced a strategic collaboration with Simcere Zaiming, an oncology-focused subsidiary of Simcere Pharmaceutical Group Ltd. The partnership centers on the development of SIM0505, a novel antibody-drug conjugate (ADC) targeting CDH6 (cadherin-6), intended for the treatment of solid tumors.
SIM0505, currently in Phase 1 clinical trials in China, employs a unique binding epitope to CDH6, a promising tumor target, offering improved tumor binding compared to existing candidates. The ADC features Simcere Zaiming’s proprietary topoisomerase 1 inhibitor (TOPOi) payload, designed to deliver broad anti-tumor effects while maintaining a favorable safety profile through high systemic clearance, expanding the therapeutic window. Preclinical studies have demonstrated potent anti-tumor activity across various solid tumor models with encouraging toxicology data.
NextCure plans to initiate clinical trials for SIM0505 in the United States in the third quarter of 2025, following clearance of the Investigational New Drug (IND) application by the U.S. Food and Drug Administration (FDA). A global dose expansion study, including multiple tumor types, is planned after the completion of the ongoing dose escalation phase in China.
The agreement also grants NextCure access to Simcere Zaiming’s proprietary linker and TOPOi payload for a separate preclinical-stage ADC targeting a novel antigen developed by NextCure. In return, Simcere Zaiming will retain rights for this ADC in the Greater China region.
Michael Richman, president and CEO of NextCure, expressed enthusiasm about the collaboration, stating, “SIM0505 has the potential to be an important new therapy for cancer patients. Partnering with Simcere Zaiming, a leader in antibody-drug conjugates, provides us an opportunity to advance a class-leading ADC with a potentially improved safety and efficacy profile.”
Renhong Tang, PhD, CEO of Simcere Zaiming, added, “Our alliance reflects NextCure’s recognition of our proprietary ADC platform, and together, we aim to accelerate drug development to benefit more cancer patients worldwide.”
Under the terms of the partnership, Simcere Zaiming is eligible to receive up to $745 million in payments across development milestones, regulatory achievements, and sales, as well as tiered royalties on net sales outside Greater China.