NextCure and Simcere collaborate on SIM0505 for solid tumors

NextCure has established a strategic alliance with Simcere Zaiming, a division of the Simcere Pharmaceutical Group, to advance the development of a novel antibody-drug conjugate (ADC) known as SIM0505. This ADC is designed to target cadherin-6 or K-cadherin (CDH6) in the treatment of solid tumors. Currently undergoing Phase I clinical trials in China, SIM0505 is anticipated to commence clinical trials in the United States by the third quarter of 2025.

This collaboration secures NextCure the rights to utilize Simcere Zaiming’s proprietary linker and topoisomerase 1 (TOPOi) inhibitor ADC payload. This payload is engineered to deliver a broad anti-tumor activity while ensuring high systemic clearance, which enhances the therapeutic potential of SIM0505. The unique binding epitope of SIM0505 reportedly increases its affinity to tumor cells compared to other similar candidates, possibly offering a more efficient therapeutic option for patients with cancer.

The agreement between the two companies stipulates that Simcere Zaiming will maintain commercial rights for SIM0505 within Greater China. In compensation, NextCure will receive an upfront payment along with additional milestone payments that may accumulate up to $745 million. Furthermore, NextCure is entitled to receive tiered royalties on net sales of SIM0505 outside of Greater China.

The development of SIM0505 represents a significant venture for both companies in the ADC landscape. Michael Richman, the president and CEO of NextCure, emphasized the potential impact of SIM0505 as a new therapeutic agent for cancer patients. He noted that their partnership with Simcere Zaiming, which is recognized for its expertise in ADC technology, presents a valuable opportunity to advance a leading ADC aimed at CDH6. According to Richman, Simcere Zaiming’s payload boasts a potent cytotoxic profile with potentially improved safety and efficacy characteristics compared to existing topoisomerase inhibitors.

The ADC’s ongoing dose escalation trials in China are set to pave the way for a global dose expansion study, which will explore its application across multiple tumor types. Renhong Tang, CEO of Simcere Zaiming, expressed satisfaction with the collaboration, highlighting the distinctive nature of SIM0505 as a CDH6-targeting ADC independently developed by Simcere Zaiming. Tang noted that this partnership underscores the recognition of Simcere Zaiming's proprietary ADC platform by NextCure. Both companies are committed to accelerating the development of SIM0505 to bring its benefits to a broader range of cancer patients worldwide.

In addition to this venture, in January 2025, Simcere Zaiming entered into an option-to-license agreement with AbbVie for the development of another ADC, SIM0500. This demonstrates Simcere Zaiming’s ongoing commitment to developing cutting-edge ADC therapies and expanding their global footprint in oncology treatment.

As the global landscape for cancer therapeutics evolves, collaborations like that of NextCure and Simcere Zaiming are crucial for the swift development and dissemination of innovative treatments. By pooling resources and expertise, these partnerships aim to make significant strides in combating cancer and improving patient outcomes across diverse populations.