Annexon, Inc.
formerly Annexon BiosciencesIPOUnlocking the next generation of complement therapies
South San Francisco, United States · Founded 2016 · $278.0M raised
- Headquarters
- South San Francisco, California
- Employees
- 1–10
- Founded
- 2016
- Business Model
- B2B
- Website
- annexonbio.com
- Total Funding
- $278.0M
- Last Round
- $125.0M Series ENov 2025
- Rounds
- 9
About
Annexon Biosciences (Nasdaq: ANNX) is a clinical-stage biopharmaceutical company developing a new class of complement medicines targeting the classical complement pathway via C1q inhibition. Its pipeline addresses autoimmune, neurodegenerative, and ophthalmic disorders, with candidates including ANX005, ANX007, and ANX009 in clinical development. The company was founded in 2011 by Arnon Rosenthal and Ben Barres.
Summary
Annexon, Inc. is a Biopharmaceutical company based in South San Francisco, United States, founded in 2016. It has raised $278.0M in total across 9 rounds, most recently a $125.0M Series E round in Nov 2025. Investors include GV, Alta Partners and Satter Investment.
Tech & App Stack
6 technologies & apps tracked
Every product and vendor across these categories, with where each signal came from.
Create a free account with 25 free credits every month, no card needed, to unlock the full tech & app stack, funding history, and valuations.
Funding History
Sign up to view the funding chart
Create a free account with 25 free credits every month, no card needed, to unlock funding history, valuations, and tech stacks.
Nov 2025
Sign up to see all 11 rounds
Series A through Series E — per-round amounts, valuations, and who invested in each round.
Investors
GV
1 round
Alta Partners
1 round
Satter Investment
1 round
Bain Capital Life Sciences
1 round
Correlation Ventures
1 round
Goldman Sachs
1 round
Wells Fargo
1 round
Omega Funds
1 round
Cowen Healthcare Investments
1 round
BlackRock
1 round
Deerfield Management
1 round
Eventide Asset Management
1 round
Farallon Capital
1 round
Janus Fund
1 round
Surveyor Capital
1 round
Adage Capital
1 round
Similar Companies
China's leading blood products manufacturer
IVI-RMA provides fertility treatments and patient-centered reproductive care, combining research,...
inVentiv Health merged with INC Research to form Syneos Health, integrating clinical and commerci...
Specialty pharmaceutical company
Altos Labs combines academic science and industry development to create medicines that restore ce...
BeOne Medicines develops transformative oncology medicines through rigorous science, an accelerat...
Your company? Embed this profile
Add the live badge to your site — it stays current as your funding data updates.
<a href="https://indexed.vc/companies/annexon-inc"><img src="https://indexed.vc/api/badge/company/annexon-inc" alt="Annexon, Inc. on Indexed.vc" width="260" height="76" /></a>