Vigil Neuroscience is a clinical-stage biotech developing treatments for neurodegenerative diseases, built around the thesis that dysfunctional microglia — the brain's immune cells — drive neurodegeneration, and that activating a microglial receptor called TREM2 can slow or halt disease. Vigil has two clinical-stage candidates. Iluzanebart is an injectable monoclonal antibody TREM2 agonist in a Phase 2 trial for ALSP, a rare, fatal, inherited neurodegenerative disease with no approved treatments and an estimated combined U.S./EU/UK prevalence of roughly 48,000 patients. Phase 2 data are expected in Q2 2025. VG-3927 is an oral, once-daily small molecule TREM2 agonist targeting Alzheimer's disease, where TREM2 loss-of-function variants appear in roughly 7–8% of patients. Phase 1 data reported in January 2025 showed favorable safety and target engagement, and Vigil plans to start a Phase 2 trial in Q3 2025. Vigil's strategy is to first establish proof-of-concept in rare, genetically defined diseases, then expand into larger populations. Vigil holds an exclusive license from Amgen covering TREM2 intellectual property for both programs, and owes Amgen regulatory and commercial milestones plus royalties on net sales if products reach market. Vigil has no approved products or commercial revenue, and funds operations through equity raises.