GB7208

GB7208 is an oral, central nervous system–penetrant, highly selective and irreversible small‑molecule inhibitor of Bruton’s tyrosine kinase (BTK) originally developed by Gossamer Bio for neuroinflammatory and neurodegenerative indications, particularly multiple sclerosis. It was designed to achieve high brain penetrance and sustained BTK target occupancy while minimizing off‑target kinase inhibition, thereby modulating B cells and myeloid cells, including microglia, within the CNS. In preclinical BTK‑dependent models of experimental autoimmune encephalomyelitis, GB7208 reduced disease severity, axonal damage, and neuroinflammation at substantially lower doses than first‑generation BTK inhibitor ibrutinib, and showed superior brain exposure versus other CNS‑directed BTK inhibitors. Development advanced through IND‑enabling and early preclinical stages for multiple sclerosis before being discontinued.