Description
The debate revealed conflicting estimates ranging from <5% to 20% for FcRn’s role in BBB transport, with species differences unresolved. This fundamental uncertainty undermines rational design of FcRn-targeted therapeutics and dosing strategies.
Source: Debate session sess_SDA-2026-04-01-gap-008 (Analysis: SDA-2026-04-01-gap-008)
Resolution criteria
Resolved when FcRn-mediated BBB antibody transport is quantified in human-relevant systems and compared against total antibody brain exposure. Required evidence includes FcRn perturbation or blocking controls, human iPSC/endothelial or ex vivo BBB data plus in vivo or clinical PK where available, estimates with confidence intervals for percent contribution, species-comparison analysis, and KG edges for FcRn, antibody format, transport route, and CNS exposure.