Swedish biotech company Cantargia presented promising preclinical data for its novel antibody-drug conjugate (ADC) targeting interleukin-1 receptor accessory protein (IL1RAP) at the American Association for Cancer Research (AACR) Annual Meeting in Chicago on April 28, 2025.
The data demonstrates the potential of IL1RAP as a target for ADC therapy across multiple cancer types, offering a new approach to precision oncology that targets both tumor cells and the tumor microenvironment.
Strong Efficacy Across Tumor Models
The anti-IL1RAP ADC was developed using an antibody selected from Cantargia's proprietary library of IL1RAP-targeting antibodies, conjugated to a tubulin-targeting cytotoxic payload using ImmunoGen's (now part of AbbVie) proprietary technology.
In preclinical studies, the ADC showed impressive efficacy with dose-dependent anti-tumor activity in models with varying levels of IL1RAP expression. Most notably, a single dose of the ADC led to 100% survival by day 95 in high IL1RAP-expressing tumor models, compared to 60% survival in animals treated with a control ADC using a non-targeting antibody with the same linker-payload.
"IL1RAP is an attractive target from an ADC perspective and the data presented show that conjugation of a toxic payload to an anti-IL1RAP antibody has strong potential as a safe and effective anti-tumor therapeutic," said David Liberg, Chief Scientific Officer of Cantargia.
Importantly, the ADC also demonstrated strong tumor growth inhibition in low IL1RAP-expressing tumor models, suggesting potential broad applicability across different cancer types regardless of target expression levels.
Favorable Safety Profile
The preclinical safety assessment revealed no marked changes in body weight, liver and kidney enzyme levels, and no histological changes in the internal organs examined. This favorable tolerability profile is crucial for ADCs, which aim to deliver potent cytotoxic agents specifically to cancer cells while minimizing damage to healthy tissues.
Strategic Expansion of IL1RAP Platform
This ADC program represents an expansion of Cantargia's IL1RAP-targeting platform, which already includes nadunolimab (CAN04) and CAN10, both in clinical development for various oncology and inflammatory indications.
"These data illustrate the strength of Cantargia's CANxx platform which contains numerous antibodies with different properties that can be developed into new IL1RAP-based therapies," Liberg added.
The IL1RAP target is particularly promising for ADC development due to its overexpression in many solid tumors and their microenvironment, providing a dual-targeting approach that could potentially improve treatment outcomes.
ADC Technology Gaining Momentum
Antibody-drug conjugates have emerged as a powerful class of cancer therapeutics, combining the precision targeting of monoclonal antibodies with the cell-killing abilities of cytotoxic agents. The field has seen significant growth in recent years, with several ADCs receiving regulatory approvals for various cancer indications.
Cantargia's approach leverages this established modality while targeting a novel protein, IL1RAP, that plays roles in both tumor growth and the immunosuppressive tumor microenvironment.
Collaborative Development
The studies were performed in collaboration with ImmunoGen, a pioneer in ADC technology that was recently acquired by AbbVie. This collaboration brings together Cantargia's expertise in IL1RAP biology with ImmunoGen's established ADC platform.
The poster presentation (number 2875), titled "IL1RAP-targeting antibody-drug conjugate: A novel therapeutic targeting both tumor cells and the tumor microenvironment," was presented by Dr. Elin Jaensson Gyllenbäck from Cantargia.
Future Development Plans
While Cantargia has not yet disclosed specific timelines for potential clinical development of the anti-IL1RAP ADC, the company indicated it is "looking forward to further optimizing and advancing the IL1RAP-targeting ADCs for use across a broad spectrum of cancers."
The company's lead candidate, nadunolimab, is currently in clinical trials for pancreatic cancer, non-small cell lung cancer, and triple-negative breast cancer, primarily in combination with chemotherapy. Early clinical data has suggested enhanced efficacy compared to chemotherapy alone.
With this promising ADC data, Cantargia continues to strengthen its position in the competitive oncology landscape by expanding its IL1RAP-targeting platform with complementary therapeutic modalities.
