LigaChemBio and Partners Reveal 5 Programs Pre-clinical Results at AACR
- STING Agonist 'LCB39' Shows Strong Potential to be Best-in-Class; Global Clinical Trials Scheduled for Early 2026
- Multiple Outcomes on Products arising from ADC Platform Licensing deal highlight the Platform’s Increasing Value
- SOTIO, a Partner in ADC Platform Technology Licensing, Chosen for Oral Presentation of LRRC15 ADC 'SOT106'

LigaChemBio (141080KS, hereinafter 'LigaChemBio') announced on the 26th that it will present preclinical research results for five programs, including the STING agonist ‘LCB39’ under development as an immuno-oncology agent, and the LRRC15 ADC ‘SOT106’ and CA242 ADC ‘IKS04’ candidates derived through its ADC platform technology licensing, at the American Association for Cancer Research (AACR 2025) Annual Meeting.

These research findings will be presented through oral presentations and posters by LigaChemBio and its partners during the AACR 2025, scheduled to be held in Chicago from April 25 to 30 (local time). The abstracts related to these presentations were made available on the conference website on the 25th.

LCB39 is a next-generation immuno-oncology candidate, proprietarily developed by LigaChemBio. It targets the STING (Stimulator of Interferon Genes) protein to activate innate immune cells. STING agonists have gained attention as a promising mechanism to overcome the limitations of existing immuno-oncology drugs. However, despite numerous attempts by global pharmaceutical companies, most have failed to develop due to issues with efficacy and side effects. LigaChemBio’s LCB39 is distinctive in that it uses proprietary technology to reduce cell permeability compared to competing STING agonists, while enhancing penetration into tumor tissues and prolonging exposure. This unique approach is expected to maintain the potent efficacy of existing STING agonists while ensuring safety, increasing the likelihood of success when LCB39 enters clinical trials in early 2026, overcoming the failures of previous competitors. LigaChemBio will unveil additional data from SITC 2024, showcasing the synergistic effects of LCB39 when used in combination with various cancer treatments, including ADCs and immune checkpoint inhibitors. This data is anticipated to boost the product’s market potential given its compatibility.

Furthermore, Preclinical results for 2 ADCs derived through the ADC platform licensing deals and Platform research result will also be presented. These results will be showcased by partners IKSUDA and SOTIO, which entered into ADC platform technology licensing agreements with LigaChemBio in 2020 and 2021, respectively. As these candidates are planned to enter global clinical trials, the value of the platform technology licensing is expected to be further highlighted.

SOT106, currently under development by Sotio, is an ADC targeting LRRC15 (Leucine-rich repeat containing protein 15) with a monoclonal antibody and LigaChemBio’s ADC platform, 'ConjuALL', combined with an MMAE payload. It is a candidate derived from a 2021 technology licensing agreement between LigaChemBio and Sotio. LRRC15, the target of SOT106, is minimally expressed in normal tissues, but is known to be overexpressed in malignant tumors such as sarcoma, glioblastoma, head and neck squamous cell carcinoma, non-small cell lung cancer, and triple-negative breast cancer, which are cancers with high unmet medical needs. LRRC15 is considered one of the promising targets for ADC therapy development. According to the published abstract, SOT106 has demonstrated strong and sustained dose-dependent tumor growth inhibition effects in various disease-related mouse models. Complete responses were also observed at a clinically relevant dose of 1mg/kg. Notably, SOT106 showed higher efficacy with lower doses and fewer administrations compared to comparator drugs, further validating LigaChemBio’s linker technology. In addition, Sotio announced that it has developed a diagnostic antibody, which will help patient populations most likely to benefit from SOT106 treatment. This development is expected to increase the likelihood of success in the upcoming Phase 1/2 clinical trials.

IKS04, currently under development by IKSUDA Therapeutics (IKSUDA), is an antibody-drug conjugate (ADC) that targets CA242 (a cancer-specific carbohydrate antigen).

IKS04 combines IKSUDAs proprietary antibody with LigaChem Biosciences (LCB)'s ADC platform ConjuALL, and LCB’s proprietary payload, a PBD prodrug (Pyrrolobenzodiazepine prodrug). LCBs platforms were accessed by IKSUDA through a license agreement with LCB in 2020 for use in the development of ADCs to numerous targets.

CA242, the target for IKS04, is known to be highly expressed in colorectal, pancreatic, and gastric cancers, while its expression in normal tissues is limited. Previous clinical studies, though unsuccessful, demonstrated the potential of CA242 as a druggable and potentially promising ADC target. However, these studies revealed the limitations of microtubule inhibitor-based payloads in gastric tumors due to their modest clinical efficacy. Therefore IKS04, which employs a potent DNA-damaging payload, such as a PBD, may provide significant improvement in clinical activity and offer an effective therapeutic option for patients with gastric cancers. LCBs prodrug approach enables tumor-ive release and activation of this potent payload for added safety.

According to IKSUDAs published abstract, CA242 has inordinately high expression abundance in high-expressing colon and gastric models, resulting in an antigen barrier which precludes tumor penetration of the ADC. Leveraging an ‘ultra-low DAR approach through co-administration of naked antibody with the ADC, IKSUDA has demonstrated an  enhancement in tumor penetration, enabling consistently low minimally effective doses of <0.5mg/kg across all CA242-expression models. As a reference, the benchmark compound cantuzumab ravtansine was inactive even at doses of 2mg/kg in these models, validating  the design hypothesis for payload mechanism ion. 

Importantly, the ultra-low DAR approach does not negatively impact toxicity and IKS04 is also associated with a favorable preclinical therapeutic index (TI), which is significantly higher than all PBD-based ADC programs that have been assessed for solid tumors to date.

In conclusion, IKS04 has demonstrated strong and consistent anti-tumor efficacy across a range of GI tumor models, including those of the stomach and colon, alongside a favorable TI. This ADC program adds further evidence of the potential clinical benefit of LCB’s proprietary PBD prodrug approach for use in ADCs to ed tumor indications. Based on these positive results, IKSUDA plans to initiate clinical trials of IKS04 using the ultra-low DAR dosage regimen in the near future. IKS04 potentially offers a new treatment option for cancers which are notoriously difficult to treat.

Iksuda also presented research results that demonstrate the superiority of the linker technology introduced by LigaChemBio. According to the published abstract, Iksuda compared an FRα (Folate-Receptor Alpha) ADC using Iksuda's proprietary 'Permalink' conjugation method with LigaChemBio’s linker and MMAE payload, maintaining the antibody, conjugation method, and payload, while applying the valine-citrulline (vc) linker, which is commonly used by most global ADC companies after the expiration of its patent. Preclinical experiments showed that the ADC using LigaChemBio’s linker exhibited superior tolerability and stability in the bloodstream compared to the ADC using the vc linker. This research result is significant as it reaffirms the superiority of LigaChemBio’s proprietary linker technology over existing linker technologies