The antibody-drug conjugate space has a problem nobody wants to talk about: resistance. You engineer a precision warhead, attach it to a targeting antibody, fire it at a tumor… and the tumor figures out how to dodge it. ADC resistance is becoming one of oncology’s most uncomfortable open questions — and ABION just walked into AACR 2026 with preclinical data that says they have a different answer.

Their platform is called iRAC — Interferon-β Antibody Conjugate — and the key difference is the payload. Where traditional ADCs deliver cytotoxic chemotherapy, ABION’s ABN202 delivers IFN-β, an immune-activating cytokine, directly to TROP2-expressing tumors. The result? You get direct tumor cell killing plus systemic CD8+ T cell activation. It’s not just a smarter bomb — it’s a bomb that recruits an army.

At AACR, ABION showed that ABN202 outperformed TROP2-targeting ADCs alone and ADC plus anti-PD-1 combinations in ADC-resistant tumor models. They didn’t disclose hard numbers — this is preclinical, so take it with appropriate seasoning — but the directional signal is clear: when the chemo payload stops working, an immune-activating payload might still have cards to play.

ABION isn’t a one-trick pony, either. The Seoul-based company has vabametkib, a c-MET inhibitor, in Phase 2 for advanced solid tumors — so there’s clinical-stage experience in the building. And the iRAC platform is described as target-agnostic, meaning TROP2 is just the first address. IND submission for ABN202 is planned for H1 2027, and they’re already shopping for partnership opportunities.

In a TROP2 landscape that includes Gilead’s Trodelvy and Kelun-Biotech’s recently approved sacituzumab tirumotecan, ABION isn’t trying to build a better ADC. They’re arguing the payload philosophy itself needs to change. That’s a bold claim at preclinical stage — but if resistance is the enemy, changing the ammunition isn’t the worst strategy.