Annexon Adds On $100M to Advance Antibodies to Treat Neurodegeneration

Xconomy San Francisco — 

Annexon Biosciences, a biotech founded in late 2014 by former Elan Pharmaceuticals executives, has added $100 million to its coffers to move its two clinical-stage programs along and to continue advancing its preclinical pipeline.

The South San Francisco-based company is developing drugs for patients with autoimmune and neurodegenerative disorders that are caused by an abnormal accumulation of the protein C1q. Typically the protein plays a key role in what’s known as the classical complement pathway, a part of the immune system. But when C1q builds up it can trigger a reaction that destroys synapses, leading to neurodegeneration.

Annexon’s C1q inhibitors are designed to stop that from happening in a set of diseases, collectively known as classical complement-mediated disorders, that affect the body, brain, and eyes.

Redmile Group, a new investor, led the round that Annexon announced Wednesday.

Annexon launched in late 2014 with a $34 million Series A financing round led by the investment arm of Novartis (NYSE: NVS). CEO Doug Love was previously an executive at Elan, where he led operations, commercial, and alliance management at the time of its 2013 acquisition by Perrigo (NYSE: PRGO).

Love and Annexon’s chief scientific officer, Ted Yednock, who was previously head of research at Elan’s pharmaceutical group, started out pushing their lead program, ANX005, in Huntington’s disease.

But the company ended up moving the drug candidate, an antibody designed to block C1q and activation of the classical complement cascade, into the clinic as a potential treatment for patients with Guillain-Barré syndrome (GBS) first. The FDA has granted ANX005 fast-track and orphan drug status, two expedited assessment programs, as a potential GBS treatment. Now Annexon plans to launch a Phase 2/3 clinical trial. (Xconomy reached out to find out more about the reprioritization of indications, but the company did not respond to a request for comment by publication time. We’ll update if we hear back.)

The antibody is in preclinical development as a potential treatment for an autoimmune disorder known as warm antibody hemolytic anemia and for amyotrophic lateral sclerosis, too. Huntington’s disease remains on the road map.

Annexon’s other clinical-stage drug candidate, ANX007, is an investigational antibody fragment designed to bind to C1q. The company is studying that potential drug in the clinic as a treatment for geographic atrophy, an advanced form of “dry” age-related macular degeneration, and glaucoma. ANX007 is formulated to be injected into the eye for neurodegenerative ophthalmic disorders.

The company last raised outside financing in late 2018. That $75 million round was led by Bain Capital Life Sciences, a new investor. Two years prior it tacked on $44 million in a financing also led by a new investor, New Enterprise Associates (NEA).

The latest round also involved new investor participation, with backing from funds and accounts managed by BlackRock (NYSE: BLK), Deerfield Management Company, Eventide Asset Management, Farallon Capital Management, Janus Henderson Investors, and Logos Capital. Participation by such funds, often considered crossover investors, is often an early indicator that a company is ramping up for an initial public offering.

Earlier backers, including Bain, NEA, Adage Capital Partners, Blackstone Life Sciences, Satter Medical Technology Partners, and Citadel’s Surveyor Capital, also invested.

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