Genentech announced that fenebrutinib (GDC-0853), a non-covalent BTK inhibitor entering Ph. III, showed significant human CNS exposure and reduced new brain lesions in Ph. II for relapsing multiple sclerosis. Fenebrutinib is the only reversible BTK inhibitor in Ph. III for MS, and has the opportunity to differentiate on safety relative to covalent inhibitors. This case study highlights notable challenges overcome in the discovery of fenebrutinib including surprising metabolism, animal-specific on-target toxicity, and more.

KLS-13019 is a CBD (cannabidiol) analogue and GPR55 (G protein-coupled receptor 55) antagonist from Kannalife Sciences, which shows promise as a novel therapeutic for neuropathic pain, particularly chemotherapy-induced neuropathic pain.

The Takeda GPR139 agonist, TAK-041 , is a CNS-penetrant GPCR agonist being explored for schizophrenia symptoms and is an interesting example of a triazinone-containing clinical candidate. GPR139 is an orphan GPCR that’s highly expressed in the human habenula, which plays a major role in avoidance behavior. Lesions in the habenula cause [...]

Vorasidenib (AG-881) is a brain-penetrant allosteric inhibitor of mutant isocitrate dehydrogenases 1 and 2 (mIDH1/2) from Agios and Celgene that made headlines summer 2023 due to its stunning efficacy for treatment of glioma in patients with mIDH1/2. This Featured Case Study reviews how it was discovered, how it works, and why it matters.

AZD4747 is a CNS-penetrant, oral KRAS G12C covalent inhibitor for the treatment of CNS-metastatic KRAS-mutant cancers. KRAS inhibitors have tended to be quite large and fall outside the range of physicochemical properties generally required for CNS permeability. (MW < 360 Da, cLogD < 2, TPSA < 90 Å2. AZD4747 is much smaller than marketed KRAS G12C inhibitors but maintains exceptional cellular potency. The team also encountered an unexpected toxicity that scientists working on covalents should pay attention to.