2026 — UM-203: Reversible Covalent STING Antagonist

One-paragraph summary

Development paper for UM-203, a reversible covalent STING inhibitor with an alkyne-thiazole warhead. Inhibits STING-dependent signaling in both mouse and human systems. Notably maintains activity against the most prevalent human STING variant (R232) and suppresses cGAS-STING pathway activation. For the project, UM-203 is the first named clinical-development-track STING antagonist beyond the H-151 research compound and resveratrol that v0.3.2 §12.7 enumerates as candidate loop-interrupters. Direct candidate for clinical-stage approval that would activate watchlist trigger WL-6 if the compound advances. Adds a specific named compound to the STING-inhibitor cure-path-arm watchlist landscape.

Claims as triples

• UM_203 — modulates → cGAS_STING_pathway [evidence: reversible covalent inhibitor, mouse + human systems, R232 variant active; confidence: emerging]
• UM_203 — modulates → neuroinflammation_glial [evidence: STING-dependent inflammatory-signaling suppression; confidence: emerging]
• cGAS_STING_pathway — responds_to → UM_203 [evidence: pharmacological inhibition demonstrated; confidence: emerging]

Triangulation notes

• First specific clinical-track STING antagonist compound named in the project evidence base (beyond H-151 research compound and resveratrol nutraceutical).
• Adds an explicit watch entry to WL-6 (clinical-stage STING inhibitors in autoinflammatory disease).
• Compatible with §12.7 (STING inhibition + resveratrol + green-light cure-path arm framing).
• Discovered via watchlist query WL-6. Pre-clinical at this stage; ingestion captures it as a candidate to track for clinical-development progress.