A first-in-class radio-theranostic for solid tumors that express STn.
A highly selective antibody paired with targeted radiation, designed to reach cancers conventional therapy cannot.
What it is
Our lead candidate is an anti-STn antibody conjugated to a radioisotope via a proprietary bioorthogonal linker, forming a radio-theranostic agent. It is designed to bind Sialyl-Tn (STn), a truncated sugar structure expressed on the surface of most solid tumors — colorectal, ovarian, gastric, pancreatic, and others — while showing minimal binding to healthy adult tissue.
The antibody has been reported in peer-reviewed literature to bind STn with greater selectivity than historical benchmark antibodies such as CC49 and B72.3, the molecules on which earlier anti-TAG72 radioimmunotherapy efforts were built.
How it works
The agent circulates through the body and accumulates at tumour sites via the antibody's high-affinity binding to STn on cancer cells. Once bound, the attached radioisotope delivers a localised dose of radiation that damages the tumour while minimising exposure to surrounding healthy tissue.
Two features are critical to its design. First, the antibody binds STn across a broad range of carcinomas while showing very limited reactivity with healthy tissue, giving it potential as a pan-carcinoma therapeutic. Second, available data suggest its binding is not blocked by circulating shed antigen — addressing a historical challenge for anti-mucin therapeutics.
Diagnose first, then treat
Our platform follows a theranostic principle: the same binding component is used first in a diagnostic imaging step, paired with a lower-dose radioisotope. This identifies which patients have tumours that take up the agent, and to what extent.
Only patients whose imaging confirms clear tumour targeting then proceed to the therapeutic dose, paired with a therapeutic radioisotope. This ensures the therapy is given to the patients most likely to benefit, and provides a measurable biomarker of engagement from the outset.
Development stage
The candidate is currently in preclinical development. Active research focuses on optimising the radioisotope conjugation chemistry, characterising the pharmacokinetic and biodistribution profile, and establishing proof-of-mechanism in relevant models.
The modular nature of the platform means the same anti-STn binding component can be paired with different radioisotopes for different clinical purposes — diagnostic imaging, therapeutic dosing, or both — providing flexibility as the programme advances toward the clinic.
Key attributes
STnRadio is in pre-clinical development. The therapeutic candidate described is subject to change as research and development progresses. No product described here is approved for use.