Annexon is a clinical-stage biopharmaceutical company developing targeted immunotherapies focused on diseases caused by abnormal activation of the classical complement pathway. Annexon's core scientific approach centers on blocking C1q, the protein that initiates the classical complement cascade, with the goal of shutting down the downstream inflammatory process that damages nerves, blood cells, and retinal cells across a range of neurological, autoimmune, and eye diseases. Annexon's two lead programs are tanruprubart, an IV antibody targeting C1q for Guillain-Barré syndrome (GBS), and vonaprument, an intravitreal C1q antibody for geographic atrophy (GA), the advanced form of dry age-related macular degeneration. Tanruprubart completed a Phase 3 trial that met its primary endpoint; Annexon filed an MAA with the EMA in January 2026 and plans to file a BLA with the FDA in 2026. Vonaprument's Phase 3 ARCHER II trial completed enrollment, with topline data expected in Q4 2026. Earlier-stage pipeline assets include ANX1502, an oral C1s inhibitor in a proof-of-concept study for cold agglutinin disease, and tanruprubart in Huntington's disease and ALS, where Phase 2 trials showed signals in patients with elevated complement activity. Annexon is pre-revenue, funding operations through equity raises, and outsources all manufacturing to contract manufacturers. If approved, Annexon plans to commercialize independently in the U.S. and key markets using a targeted sales force, given that both GBS and GA are treated by specialists.