NextCure Expands ADC Portfolio with $745M Simcere Deal, Advancing Solid Tumor Therapies

NextCure, a Maryland-based biopharmaceutical company, has significantly bolstered its antibody-drug conjugate (ADC) pipeline through a lucrative partnership with China's Simcere Pharmaceutical Group. The deal, announced on June 16, 2025, grants NextCure ex-China rights to SIM0505, a novel ADC targeting CDH6 for the treatment of solid tumors.

Deal Structure and Financial Terms

The agreement, valued at up to $745 million, includes an undisclosed upfront fee, along with potential development, regulatory, and sales milestones. NextCure will also pay tiered royalties on any future sales outside of Greater China. In return, NextCure gains access to Simcere's proprietary linker and topoisomerase 1 inhibitor (TOPOi) payload technology, which it plans to utilize in developing an additional preclinical ADC against an undisclosed target.

Michael Richman, NextCure's president and CEO, highlighted the potential of SIM0505, stating, "Their proprietary payload is a potent cytotoxin with a potentially improved safety and efficacy profile compared to other topoisomerase inhibitors."

Clinical Development and Strategic Implications

SIM0505 is currently undergoing Phase I dose escalation trials in China under Simcere's supervision. NextCure aims to initiate its own Phase I trial in the United States by the third quarter of 2025, taking the lead in development outside of China.

This partnership marks a significant step in NextCure's strategic pivot towards ADCs, which began in late 2023. The company's pipeline now includes two ADC candidates:

1. SIM0505: The newly acquired CDH6-targeted ADC from Simcere
2. LNCB74: An existing ADC for solid tumors, developed in collaboration with LigaChem

The addition of SIM0505 aligns with NextCure's renewed focus on ADC technology, following the company's decision to halt development of other programs in favor of its B7-H4 ADC in November 2024.

Industry Context and Market Trends

NextCure's deal with Simcere is part of a broader trend in the biopharmaceutical industry, with many companies seeking to acquire assets from Chinese biotechs. While obesity drugs have garnered significant attention, ADCs have seen comparable activity. Notable recent transactions in the ADC space include:

• GSK's acquisition of two ADCs from DualityBio and Hansoh Pharma for gastrointestinal and lung cancers, as well as sarcomas, totaling nearly $3 billion
• Gilead's $415 million deal with Tubulis for "ultra-stable ADCs" in December 2024
• Roche's $1 billion investment in a Phase I ADC from Innovent for small cell lung cancers in January 2025

These deals underscore the growing interest in ADC technology and its potential in oncology treatment.