Vertex’s VX-548 is a potential first-in-class, exquisitely selective, oral NaV1.8 inhibitor that recently captured headlines for its positive Ph. III data. With the ongoing opioid epidemic throughout the US, there is an urgent unmet medical need for non-addictive pain medications as alternatives to opioids. They plan to file an NDA by mid-2024 for the treatment of moderate-to-severe acute pain. This case study highlights what’s publicly known about Vertex’s journey in pain leading up to the Ph. III readout for VX-548, and why this is such a watershed moment for pain management.

Zuranolone (ZURZUVAE™) is an oral positive allosteric modulator of CNS GABA signaling developed by Sage Therapeutics, in collaboration with Biogen, which was approved in August 2023 by the FDA for the treatment of postpartum depression (PPD). In 2019 Sage had received approval for brexanolone (ZULRESSO™), an IV formulation of the endogenous GABA PAM neurosteroid hormone for PPD, but an oral drug is expected to greatly increase access to treatment. Zuranolone was also investigated for major depressive disorder, although the FDA declined to extend approval for this indication.

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 [...]

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.

The Takeda AMPA-R potentiator, TAK-653 , is a glutamate-dependent potentiator that exhibits minimal agonism. AMPA-R agonism is associated with seizure risk and bell-shaped dose-response effects. As reviewer Jake Schwarz notes, companies including Cortex Pharmaceuticals (now RespireRx) and Lilly have been trying to develop AMPA modulators for [...]