Annexon Biosciences is a clinical-stage biopharmaceutical company headquartered in Brisbane, California, focused on developing novel therapeutics that inhibit the complement cascade to treat neurodegenerative diseases and autoimmune conditions. The company's lead asset targets C1q, the initiating molecule of the classical complement pathway, which plays a critical role in synaptic elimination and neuroinflammation[@annexon2024].
Company Overview
Annexon was founded in 2011 and went public in 2020 (NASDAQ: ANNX). The company leverages its understanding of complement biology to develop treatments for conditions where complement-mediated inflammation contributes to disease pathology.
Funding
IPO: 2020 (NASDAQ: ANXN)
Market Cap: ~$100M (2026)
Leadership
CEO: Douglas Love (since 2019)
Founded: 2011
Headquarters: Brisbane, California
Employees: ~100-150
Pipeline
| Drug Candidate | Indication | Stage | Mechanism | Notes | |----------------|------------|-------|------------|-------| | ANX005 | Guillain-Barré Syndrome | Phase 3 | Anti-C1q mAb | Received FDA Fast Track designation | | ANX005 | Huntington's Disease | Phase 2 | Anti-C1q mAb | Targeting complement-mediated neurodegeneration | | ANX007 | Geographic Atrophy (GA) | Phase 2 | Anti-C1q Fab | Intravitreal formulation | | ANX010 | Amyotrophic Lateral Sclerosis (ALS) | Preclinical | Anti-C1q mAb | Pipeline expansion |
Clinical Programs
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Overview
Annexon Biosciences is a clinical-stage biopharmaceutical company headquartered in Brisbane, California, focused on developing novel therapeutics that inhibit the complement cascade to treat neurodegenerative diseases and autoimmune conditions. The company's lead asset targets C1q, the initiating molecule of the classical complement pathway, which plays a critical role in synaptic elimination and neuroinflammation[@annexon2024].
Company Overview
Annexon was founded in 2011 and went public in 2020 (NASDAQ: ANNX). The company leverages its understanding of complement biology to develop treatments for conditions where complement-mediated inflammation contributes to disease pathology.
Funding
IPO: 2020 (NASDAQ: ANXN)
Market Cap: ~$100M (2026)
Leadership
CEO: Douglas Love (since 2019)
Founded: 2011
Headquarters: Brisbane, California
Employees: ~100-150
Pipeline
| Drug Candidate | Indication | Stage | Mechanism | Notes | |----------------|------------|-------|------------|-------| | ANX005 | Guillain-Barré Syndrome | Phase 3 | Anti-C1q mAb | Received FDA Fast Track designation | | ANX005 | Huntington's Disease | Phase 2 | Anti-C1q mAb | Targeting complement-mediated neurodegeneration | | ANX007 | Geographic Atrophy (GA) | Phase 2 | Anti-C1q Fab | Intravitreal formulation | | ANX010 | Amyotrophic Lateral Sclerosis (ALS) | Preclinical | Anti-C1q mAb | Pipeline expansion |
Clinical Programs
ANX005 in Huntington's Disease
Huntington's disease (HD) is a fatal genetic neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and psychiatric symptoms. Annexon's approach targets C1q, which is elevated in HD brains and contributes to synaptic dysfunction and neuronal loss[@anx2023].
The Phase 2 trial of ANX005 in HD patients evaluated safety and biomarkers of complement activation. The company reported that ANX005 was generally well-tolerated and showed evidence of target engagement.
ANX005 in Guillain-Barré Syndrome
Guillain-Barré Syndrome (GBS) is an acute autoimmune disorder where the immune system attacks peripheral nerves. ANX005 has been evaluated in a Phase 1b/2 study showing promising results in reducing complement activation markers[@synaptic2022].
ANX007 in Geographic Atrophy
Geographic atrophy is an advanced form of age-related macular degeneration (AMD) leading to irreversible vision loss. ANX007 is being developed as an intravitreal therapy to inhibit C1q-mediated inflammation in the retina[@fda].
Science and Technology
Annexon's platform is built on the understanding that the [complement system](/entities/complement-system), particularly C1q, plays a dual role in immune surveillance and pathological inflammation. In neurodegenerative diseases, excessive C1q activation leads to:
Annexon has collaborated with academic institutions and has received grant funding from the Huntington's Disease Society of America and other organizations to support its clinical programs.