[ASCO 2025] How do LigaChem's ADCs differ from existing drugs?

CHICAGO, Ill. -- By Hong Sook, Korea Biomedical Review correspondent -- “There have been recurring toxicity issues with deruxtecan (DXd)-based antibody-drug conjugates (ADCs). The absence of this toxicity differentiates our ADC linker platform.”

LigaChem Biosciences visited the American Society of Clinical Oncology 2025 Annual Meeting (ASCO 2025) in Chicago, from May 30 to Jun 3 to explore clinical strategies and understand global trends in anticancer drug development.

At ASCO 2025, Enhertu (trastuzumab deruxtecan) and Trodelvy (sacituzumab govitecan), two leading ADC drugs, attracted attention by presenting research data on various cancers.

How do Korean ADC development companies view this global trend in anticancer drug development? Korea Biomedical Review met with Chung Chul-woong, head of ADC Research at LigaChem Biosciences, one of the leading Korean biotechs, to learn about the company's strategies for developing anticancer drugs, including ADCs.

Question: What is the primary purpose of your attending ASCO this year?

Answer: The primary purpose of attending ASCO is to see firsthand the clinical data of competitors and learn about the latest clinical designs and strategies. LigaChem has multiple drug candidates entering clinical trials, so we needed to see competitors' clinical data and flow at the conference.

Q: LigaChem has recently been pursuing its clinical trials. Do you plan to focus more on expanding your clinical capabilities?

A: Ultimately, we needed to build our clinical capabilities, but we were limited by capital and manpower, so we focused on technology transfer. Now that we have the funding from the technology transfer, accumulated clinical experience, and U.S.-based manpower, we can do our clinical trials. This is an evolution of LigaChem's strategy.

Q: Interim results were announced for LNCB74, a B7-H4-targeting ADC pipeline being co-developed with NextCure. How is it progressing?

A: Early-phase dose escalation trials are currently underway in various solid tumors. Subject enrollment is ongoing in ovarian, breast, and biliary cancers refractory to existing therapies. NextCure is leading the clinical trial, but all decisions, including site selection, are being made collaboratively. This project is essentially NextCure’s sole pipeline, so we are focused on developing that pipeline.

Q: What did you pay the most attention to during the conference?

A: Recurring toxicity issues have been reported with DXd-based ADCs. However, LigaChem's linker platform is different because it does not produce such toxicity. Many of our partners have noted its toxicity avoidance potential.

Q: What is LigaChem's linker toxicity avoidance technology?

A: DXd toxicity is primarily caused by premature or unintended cleavage of the linker, whereas LigaChem's linkers are structurally designed to be untruncated. This difference creates a different toxicity profile.

Q: LigaChem seems to focus on developing small molecules, which has always been its strength. This is especially true for LCB39, a small molecule-based immuno-oncology pipeline also entering clinical trials.

A: It is a STING-targeting drug and is being prepared for IND filing next year. We have balanced the therapeutic window between toxicity and efficacy through the differentiated design of the drug structure, and we are particularly encouraged by the meaningful response in human blood-based ex vivo studies.

Q: What are you keeping an eye on regarding your development strategy?

A: The primary focus is on developing new payloads. The toxicity of the current ADC platform is due not only to the linker but also to the payload characteristics. We need a payload with a new mechanism that can clearly distinguish between cancer cells and normal cells, and we are putting a lot of research into this.

Q: Are you interested in utilizing targeted protease (TPD) technology as a payload?

A: We have already been working on TPDs since 2017. We don't have any data ready to release into the pipeline yet, but we continue working on it.

Q: Would you consider collaborating with Korean companies on new payloads or linker technologies?

A: Many Korean companies started with antibody-based ADCs, but few have secured linkers or payloads independently. LigaChem, on the other hand, started from a small molecule base, so we have strengths in payloads and are pursuing various joint research programs.

Q: What is the future direction of LigaChem's drug development?

A: We are driven by how much we can invest in R&D, not just how much we can earn. We aim to grow into a company that can invest trillions in R&D annually. We will have a pipeline to take to phases 2 and 3 through our clinical trials. We have a realistic goal of having our first market-approved product by 2030.