Recent Updates
Recently added Catalysts

ANX005

Phase 3

Guillain-Barre Syndrome | Small molecule | Neurology |Annexon, Inc.|Last Updated: Aug 25, 2026

Success Probability

Subscribe to view

Market & Valuation

Subscribe to view

Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLEDDMC
Total Trials1
Total Enrollment242

FDA Designations

ORPHAN_DRUGFAST_TRACK

Clinical trial landscape

ANX005 · 5 trials · 5 indications

Phase 3 1Phase 2 3Phase 1 1
NCT04701164Efficacy and Safety of ANX005 in Subjects With Guillain-Barré SyndromeGuillain-Barre Syndrome
COMPLETED242 Analytics
PHASE3COMPLETED
Efficacy and Safety of ANX005 in Subjects With Guillain-Barré Syndrome
Guillain-Barre SyndromeUnlock trial analytics

Study Endpoints

Primary Endpoints

GBS Disability Score (GBS-DS) at Week 8
Week 8
Number of Participants with Adverse Events
Through Month 6

Number participants recently diagnosed with GBS who experience adverse events.

Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Day 1 through Day 71

An adverse event (AE) was any untoward medical occurrence in a participant who had been administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the product and therefore could be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a pharmaceutical product. An AE could arise with any use, route of administration, formulation, dose (including an overdose), or when used in combination with another pharmaceutical product. A TEAE was an AE with an onset date/time after the first infusion of ANX005 until the end of the study. A summary of serious and all other non-serious adverse events regardless of causality is located in the Adverse Events module.

Maximum Change From Baseline in Hemoglobin Levels
Baseline up to Day 71

Maximum change from Baseline was calculated as the maximum post-Baseline value observed up to Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Change From Baseline in Lactate Dehydrogenase Levels at Day 71
Baseline, Day 71

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Change From Baseline in Percentage of Reticulocytes/Total Cells Count at Day 71
Baseline, Day 71

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Change From Baseline in Haptoglobin Levels at Day 71
Baseline, Day 71

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Change From Baseline in Total Bilirubin Levels at Day 71
Baseline, Day 71

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Change From Baseline in Indirect Bilirubin Levels at Day 71
Baseline, Day 71

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Number of Participants Who Experienced Treatment-Emergent Adverse Events
Up to Week 36
Actual Dose of ANX005 Administered on Day 1
Day 1
Actual Dose of ANX005 Administered on Week 22
Week 22
Area Under the Concentration Versus Time Curve From Time 0 to t (AUC0-t) of ANX005 at Day 1
Pre-dose up to 4 hours post-dose on Day 1
CSF Free Complement Component 1q (C1q) at Day 1
Predose at Baseline (Day 1)
Blood Free C1q at Day 1
Predose at Baseline (Day 1)
Change From Baseline in Complement C4a in CSF at Week 24
Baseline, Week 24
Change From Baseline in Complement C4a in CSF at Week 36
Baseline, Week 36
Change From Baseline in CSF NfL Level at Week 24
Baseline, Week 24
Change From Baseline in CSF NfL Level at Week 36
Baseline, Week 36
Change From Baseline in Blood NfL Level at Week 24
Baseline, Week 24
Change From Baseline in Blood NfL Level at Week 36
Baseline, Week 36
Safety and tolerability of ANX005 when administered in combination with IVIg: incidence of TEAEs, SAEs, AE's
6 months

As measured by incidence of TEAEs, SAEs, AE's related to ANX005, SAE's related to ANX005, Grade 3 or higher AEs, Grade 3 or higher AEs related to ANX005, AEs leading to study or treatment discontinuation.

Secondary Endpoints

Medical Research Council (MRC) Sum Score at Week 8
Week 8
MRC Sum Score at Day 8
Day 8
Duration (Days) of Ventilation Support Over 26 Weeks
26 weeks
Unlock Study Endpoints

Study Design & Arms

AllocationRANDOMIZED
MaskingQUADRUPLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
ANX005 Treatment Group - Dose 1EXPERIMENTALParticipants will receive a single IV infusion of ANX005 (Dose 1) on Day 1.
ANX005 Treatment Group - Dose 2EXPERIMENTALParticipants will receive a single IV infusion of ANX005 (Dose 2) on Day 1.
Placebo GroupPLACEBO_COMPARATORParticipants will receive a single IV infusion of placebo on Day 1.
ANX005EXPERIMENTALParticipants will receive two once-weekly doses of ANX005 at specific time points
Open Label Treatment ArmEXPERIMENTALOne (1) dose of ANX005, 75 mg/kg, will be administered IV. IVIg, 0.4 g/kg, will be administered for 5 consecutive Days.

Interventions

NameTypeDescription
ANX005DRUGSolution for intravenous infusion
PlaceboDRUGSolution for intravenous infusion
Intravenous immunoglobulinDRUGinvestigational drug
Unlock Study Design Details

Eligibility Criteria

Age Range16 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites11

Inclusion Criteria: * Diagnosis of GBS according to the National Institute of Neurological Disorders and Stroke Diagnostic Criteria for Guillain-Barré Syndrome. * Onset of GBS-related weakness ≤10 days prior to start of infusion. * GBS-DS score of 3,4, or 5 at screening and at Day 1 prior to infusi...

Countries:BangladeshPhilippinesUnited StatesAustraliaAustriaBulgariaCanadaDenmark
Unlock Eligibility Criteria

Recent Changes (Last 90 Days)

MEDIUMJul 31, 2026NCT04691570TRIAL_REMOVED: changed
MEDIUMJul 31, 2026NCT04691570TRIAL_REMOVED: changed
MEDIUMJul 31, 2026NCT04691570TRIAL_REMOVED: changed

Frequently asked questions about ANX005

What is ANX005 used for?

ANX005 is an investigational small molecule being developed for neurological and autoimmune conditions, including Huntington Disease, Warm Autoimmune Hemolytic Anemia (wAIHA), Guillain-Barré Syndrome, and Amyotrophic Lateral Sclerosis. It is currently in clinical development and has not been approved by the FDA.

Who makes ANX005?

ANX005 is being developed by Annexon, Inc., a biopharmaceutical company traded on the NASDAQ under the ticker symbol ANNX. The company is conducting clinical trials to evaluate the drug's safety and efficacy in several indications.

What phase is ANX005 in?

ANX005 has completed Phase 1, Phase 2, and Phase 3 clinical trials. It has received Orphan Drug and Fast Track designations from the FDA, but it remains an investigational drug and is not yet approved for any indication.

What clinical trials is ANX005 in?

ANX005 has been studied in several completed trials, including NCT04035135 in Guillain-Barré Syndrome, NCT04514367 in Huntington Disease, NCT04691570 in Warm Autoimmune Hemolytic Anemia, and NCT04701164 in Guillain-Barré Syndrome. These trials were not randomized, double-blind, or controlled.

Is ANX005 the same as any other drug?

No alternative names for ANX005 have been reported. The drug is identified solely by its code name ANX005 in clinical trial registries and scientific literature.