The same week Annexon Biosciences announced it had raised $100 million in private financing to advance its research of antibody drugs to treat neurodegeneration, the company filed paperwork with regulators indicating its intention to tap the public markets, too.
The South San Francisco-based company has two clinical-stage product candidates, both of which are designed to inhibit a protein known as Cq1, which plays a key role in an immune system called the classical complement cascade. Its most advanced, ANX005, is being studied as a potential treatment for the autoimmune disease Guillain-Barre syndrome (GBS), a disorder called warm autoimmune hemolytic anemia in which the immune system prematurely attacks the body’s own red blood cells, and in two neurodegenerative conditions, Huntington’s disease and amyotrophic lateral sclerosis.
According to its prospectus, Annexon anticipates initial data from Phase 2 trials in all those indications next year, except for the GBS study, which is expected to yield Phase 2/3 data in 2023.
Annexon is also in the clinic with an antibody fragment, ANX007, evaluating its potential neuroprotective benefits for patients with an advanced form of “dry” age-related macular degeneration called geographic atrophy. A subcutaneous drug candidate, ANX009, is in preclinical development as a potential treatment for systemic autoimmune diseases.
The company’s IPO is intended to help pay for those studies as well as advance its earlier-stage and next-generation drug candidates. The company set a preliminary target of $100 million for the offering and has applied to list on the Nasdaq exchange under the stock symbol “ANNX.”
Discoveries related to complement-mediated neurodegeneration by the late Ben Barres, a neuroscientist and former chairman of Stanford University’s Department of Neurobiology known for his research into glial cells, underpinned the company’s formation. Barres in 2011 teamed up with former Genentech scientist Arnon Rosenthal, who served as its founding CEO, to start Annexon. (Rosenthal is also a co-founder of Alector (NASDAQ: [[ticker:ALEC]]), another neuroscience company based in South San Francisco, and, before that, co-founder and former chief scientist at Rinat Neuroscience.)
The biotech made its public debut in 2014 with $34 million in Series A backing. In 2016 it raised $44 million more; then, in December 2018, another $75 million. This month came its largest round yet, of $100 million.
Annexon’s largest outside shareholders are Bain Capital, which owns 13.4 percent of its shares; Clarus Lifesciences, which holds 11.9 percent; and NEA, with 11.7 percent. Novartis Bioventures has just shy of 10 percent.
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