Rare disease drugmaker · based in Brisbane, United States · founded 2011 · ticker ANNX · annexonbio.com
Annexon Biosciences works on Guillain-Barré Syndrome, one of the rare diseases we track.
Latest news. Tanruprubart (ANX005) for Guillain-Barré syndrome is under EU review, with a US FDA application expected in the fourth quarter of 2026; Phase 3 vonaprument data in geographic atrophy are due the same quarter (Annexon, August 12, 2026). Annexon second quarter 2026 results, August 12, 2026
Annexon Biosciences is a clinical-stage biopharmaceutical company developing therapies that inhibit complement C1q for rare neuroinflammatory and neurodegenerative diseases. The company's lead candidate ANX005 completed Phase 3 for Guillain-Barré syndrome, with a BLA submission expected in the fourth quarter of 2026 and an EU MAA filed in January 2026. ANX005 also completed Phase 2 studies in Huntington's disease in 2022 and ALS in 2024.
Annexon Biosciences clinical trials
We did not find active Annexon Biosciences trials for the rare diseases we track on ClinicalTrials.gov right now.
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Guillain-Barré syndrome is a rare autoimmuneneurological disorder in which the body's immune system attacks the peripheral nerves, causing rapidly progressive muscle weakness that typically starts...
How common: 1 in 60,000 people per year in the U.S. (3,000 to 6,000 new cases annually)
Where to get support
Patient groups can explain a diagnosis, point you to specialists and tell you about trials before they open. Annexon Biosciences's own site is annexonbio.com, and our help paying for treatment page lists drugmaker programs and charity funds.
1 shared disease, including Guillain-Barré Syndrome
Questions about Annexon Biosciences
Tanruprubart (ANX005), a single-infusionantibody for Guillain-Barré syndrome, which has no FDA-approved drug today.
How it works: blocks C1q, the protein that starts the classical complement cascade, so the immune attack on the nerves is stopped at its first step.
Status: Phase 3 complete. Filed in Europe in January 2026 and still under review there. Annexon said on November 9, 2026 that it expects to file with the FDA this quarter, the fourth quarter of 2026.
Today's treatment: intravenousimmunoglobulin or plasma exchange.
Two more uses of the same idea, blocking complement at C1q.
Eye: vonaprument (ANX007), injected into the eye, is in Phase 3 for geographic atrophy, the advanced dry form of age-related macular degeneration, with the Month 15 primary endpoint due in the fourth quarter of 2026 and the Month 24 result in the third quarter of 2027.
Brain: tanruprubart completed Phase 2 studies in Huntington's disease in 2022 and ALS in 2024, and Annexon's November 9, 2026 update lists no active program in either disease.
It acts at the top of one branch of the cascade instead of near the bottom of all of them.
Approved drugs: Soliris and Ultomiris block C5, near the end of the cascade where all the pathways meet, and Fabhalta blocks factor B in the alternative pathway. Enjaymo blocks C1s, the step right after C1q in the same classical branch, and is approved for cold agglutinin disease.
Annexon's drugs: C1q sits at the start of the classical pathway, the branch triggered when antibodies bind to tissue, so blocking it stops that branch before it starts and leaves the other pathways working.
Why it matters: Annexon's thesis is that the classical pathway is what tags nerve connections and retinal cells for destruction in the diseases it targets.
Brisbane, California, in the San Francisco Bay Area, and yes.
Founded: 2011.
Ticker: ANNX on the Nasdaq.
Products: none approved yet; Annexon is a rare disease specialist in the clinical stage.
Only through a clinical trial or an expanded access arrangement, since it is not approved anywhere as of November 2026.
Trials: Annexon's open-labelPhase 3 FORWARD study (NCT07020819) is recruiting people aged 8 to 85 at 30 open sites as of October 29, 2026, 22 in the US and 8 in the United Kingdom, Denmark, Spain and France, and the Guillain-Barré syndrome page lists every recruiting study. Annexon said on November 9, 2026 that 18 patients aged 12 to 78 have been treated in FORWARD to date.
Expanded access: our guide to continued access options explains how it works while an application is under review.
Annexon Biosciences has active programs across 1 rare disease: Guillain-Barré Syndrome. Each disease page on Trial Friend shows the latest recruiting trials, FDA-approved treatments, and patient resources.
The clinical trials section on this page shows active and recruiting rare disease trials sponsored by Annexon Biosciences, pulled live from ClinicalTrials.gov. Each trial card includes the study phase, recruitment status, conditions being studied, number of trial sites, and a direct link to the full study record. You can also explore individual disease pages to see trials from all sponsors for a specific condition.
To explore enrollment, find a recruiting trial in the clinical trials list on this page and click "View full study" to see the full ClinicalTrials.gov record, which includes eligibility criteria, study locations, and contact information for each trial site. Your doctor can also help determine if a specific trial is appropriate for your condition. Not all trials are open at every location, so check the site list for one near you.
None that we track as of November 2026. No Annexon Biosciences label in the FDA's openFDA database matches a rare disease on Trial Friend, which usually means the company has no approved product yet or its approved drugs are for common conditions.
In development: the trials list on this page shows what Annexon Biosciences is recruiting for now, and the FDA calendar lists any application once a decision date is public.