tanruprubart (ANX005) / Annexon Biosci - LARVOL DELTA

Acute Management of Guillain-Barré Syndrome: A Narrative Review. (PubMed, Arch Intern Med Res) - "Although the C5 inhibitor eculizumab failed to improve outcomes in a phase 3 trial, early results with the upstream C1q inhibitor ANX005 suggest that earlier complement inhibition may reduce nerve injury and improve functional outcomes. Other investigational approaches include IgG-degrading enzymes such as imlifidase, FcRn inhibitors such as efgartigimod, regulatory T-cell therapies, and regenerative strategies...Important gaps also remain in subtype-specific treatment, nerve regeneration, long-term rehabilitation, treatment-related fluctuations, and access to care. Future research should focus on more targeted and individualized therapies that address both immune-mediated injury and subsequent nerve damage."

Clinical • Journal • Pain • Respiratory Diseases

An Open Label Study of ANX005 in Participants With, or at Risk for, Manifest Huntington's Disease (clinicaltrials.gov) - P2 | N=28 | Completed | Sponsor: Annexon, Inc. | Phase classification: P2a ➔ P2

Phase classification • CNS Disorders • Genetic Disorders • Huntington's Disease • Movement Disorders • CSF NfL

Tanruprubart in GBS: Targeting Early Complement-Associated Inflammation Conserved Across the Clinical Spectrum and Regions (EAN 2026) - "Across geographically and clinically diverse cohorts, GBS demonstrated a conserved, complement-linked early inflammatory signature peaking at Day 8, defining a narrow window where short-duration upstream complement inhibition is most impactful. Tanruprubart rapidly and durably suppressed this inflammatory cascade across strata and regions, highlighting C1q inhibition as a mechanism-targeted strategy for GBS and supporting extrapolation of these biomarker effects to US patients."

Clinical • Inflammation

Targeted Immunotherapy with Tanruprubart (ANX005) Reduces Ventilation Requirements in Guillain–Barré Syndrome: A Phase 3 Subgroup Analysis (EAN 2026) - P3 | "Tanruprubart reduced the duration of mechanical ventilation in individuals with GBS, especially among those with more severe disease."

P3 data

Tanruprubart, anti-C1q therapy, Accelerates Recovery and Reduces Ventilation in Severe Guillain-Barré Syndrome: Results from the Phase 3 GBS-02 Trial (EAN 2026) - P3 | "In this Phase 3 study of severe GBS, tanruprubart improved recovery-related outcomes, including earlier independent walking and shorter ventilation duration, with the possibility of shorter time in the ICU, consistent with clinically meaningful benefit."

P3 data • Immunology

Safety Profile of tanruprubart (ANX005) in Patients with Guillain–Barré Syndrome: A Randomised, Placebo-controlled Phase 3 Study (EAN 2026) - "Single-dose tanruprubart was generally well-tolerated. Common TEAEs were associated with disease course. Tanruprubart did not increase risk of infections with encapsulated bacteria, despite most participants not receiving prophylactic antibiotics."

Clinical • P3 data • Immunology • Infectious Disease

A Novel Guillain–Barré Syndrome Clinical Progression Scale to Characterise the Patient’s Care Journey: Utilisation in a Phase 3 Trial of Tanruprubart (EAN 2026) - P3 | "CLIPS captured patients’ transitions through levels of care, providing a pragmatic lens to interpret treatment benefit. Early separation at Week 4 favouring tanruprubart supports a clinically meaningful shift toward lower resource intensity during early GBS."

Clinical • P3 data • Immunology • Infectious Disease • Novel Coronavirus Disease

Tanruprubart Rapidly Improves Health-related Quality of Life in Patients with Guillain–Barré Syndrome: A Randomised, Placebo-controlled Ph3 Study (EAN 2026) - P3 | "Tanruprubart demonstrated rapid and sustained improvements in HRQoL, consistent with observed objective clinical benefits, supporting its potential as a targeted immunotherapy for GBS."

Clinical • HEOR

Tanruprubart monotherapy in Guillain-Barré syndrome: Patient case from the open-label FORWARD study (EAN 2026) - No abstract available

Clinical • Monotherapy

Early Targeted C1q Inhibition With Tanruprubart Improves Functional Recovery in Guillain-Barré Syndrome: Results From a Phase Three Study (AAN 2026) - P3 | "Conclusions Patients diagnosed and treated early in the disease course (≤5 days from onset), or with limited axonal damage (low baseline NfL), achieved greater functional improvement (GBS-DS). These results support the pivotal role of classical complement activation in GBS, highlight the need for rapid diagnosis, and the benefit of early targeted C1q inhibition."

Inflammation

An Open-label Study Evaluating the Pharmacokinetics, Pharmacodynamics, Efficacy, and Safety of Tanruprubart Single Dose in Participants From North America and Europe With Guillain-Barré Syndrome (AAN 2026) - "The study is powered to compare MRC sumscore at Week 1 with an IVIg-treated, external control group from the International GBS Outcome Study database. Conclusions This study will add to the extensive body of evidence showing the benefit of tanruprubart in patients with GBS and confirm previous study findings in a population from North America and Europe."

Clinical • PK/PD data

An Open-Label Phase 1b Study of the Safety, Pharmacokinetics, Pharmacodynamics, and Clinical Activity of ANX005 in Patients with Huntington's Disease. (PubMed, Mov Disord) - P2a | "Overall, AEs with ANX005 administration were manageable, and most patients received all planned doses. Evidence of clinical improvement with ANX005 was observed in patients with higher baseline complement activity, supporting future study in patients with HD."

Journal • P1 data • PK/PD data • CNS Disorders • Hematological Disorders • Huntington's Disease • Immunology • Inflammation • Inflammatory Arthritis • Lupus • Movement Disorders • Parkinson's Disease • Pneumonia • Systemic Lupus Erythematosus • C1Q

Annexon Submits Tanruprubart Marketing Authorization Application to the European Medicines Agency for Guillain-Barré Syndrome (GlobeNewswire) - "A Biologics License Application (BLA) submission to the FDA with data from the FORWARD study is planned in 2026."

EMA filing • FDA filing • Rare Diseases

An Open Label Clinical Study to Evaluate Tanruprubart (Also Commonly Known as ANX005) in Participants With Guillain-Barré Syndrome (FORWARD Study) (clinicaltrials.gov) - P3 | N=30 | Recruiting | Sponsor: Annexon, Inc. | Not yet recruiting ➔ Recruiting | Initiation date: Jun 2025 ➔ Sep 2025

Enrollment open • Trial initiation date • Complement-mediated Rare Disorders

Recent Corporate and Clinical Program Updates: Tanruprubart (ANX005) in GBS (GlobeNewswire) - "Next Milestones: (i) Tanruprubart MAA submission expected in January 2026; (ii) Update on FDA BLA submission upon further regulatory dialogue; (iii) Initial FORWARD data anticipated in 2026."

EMA filing • FDA filing • P3 data • CNS Disorders

GUILLAIN BARRÉ SYNDROME (WCN 2025) - "Fifth, recent studies provided first evidence for a positive effect on clinical recovery of two new treatments: imlifidase (IgG cleaving enzyme) and tanruprubart (C1q inhibitor)...Major challenges for the future include finding more effective and personalized treatments, which are also affordable in low- and middle-income countries, and to prepare for outbreaks of infections as potential triggers for GBS. Up to date information on the management of GBS is available via the knowledge hub at The Global Health Network."

CNS Disorders • NEFL

Therapeutic strategies for Huntington's disease: current approaches and future direction. (PubMed, Neurodegener Dis Manag) - "Additionally, the potential of VTX-003 and ANX005 in mitigating disease progression is explored. Despite these promising therapies, challenges persist, particularly in long-term assessment, delivery strategy, and off-target effects. Considering the future landscape and need, the review has strengthened the need of therapeutic interventions to enhance efficacy and safety, ultimately improving the quality of life of HD patients."

Journal • Review • CNS Disorders • Cognitive Disorders • Gene Therapies • Huntington's Disease • Movement Disorders • Psychiatry • Targeted Protein Degradation

An Open Label Clinical Study to Evaluate Tanruprubart (Also Commonly Known as ANX005) in Participants With Guillain-Barré Syndrome (FORWARD Study) (clinicaltrials.gov) - P3 | N=30 | Not yet recruiting | Sponsor: Annexon, Inc.

New P3 trial • Complement-mediated Rare Disorders

Microglia in the Rostral Ventromedial Medulla Mediate Synaptic Pruning via the C1q/C3-CR3 Signaling Pathway-A Mechanism for the Chronic Orofacial Pain. (PubMed, Mol Neurobiol) - "During the modeling process, administered daily stereotactic injections of ANX-005 and minocycline into the RVM, which resulted in a notable recovery in the rats' pain threshold and a significant increase in C1q/C3 and microglia in the RVM of CFA rats. This process results in a reduction in the proportion of excitatory synapses and a disruption in the physiological balance between RVM descending facilitation and descending inhibition. This leads to the predominance of descending facilitation in pain transmission in the RVM, which in turn facilitates the chronification of orofacial pain."

Journal • Pain • C1Q

Evolving understanding of Guillain-Barré syndrome pathophysiology and the central role of the classical complement pathway in axonal injury. (PubMed, Front Neurol) - "Given its evolutionary role in antibody binding and activating the classical complement pathway, the complement component C1q has been proposed as a therapeutic target in GBS. The clinical trial program of the C1q inhibitor ANX005, including placebo-controlled, double-blind phase 1b and phase 3 trials in GBS, provides insight into the pathophysiology of GBS and the efficacy of C1q inhibition regardless of neurophysiologic classification or geographic location."

Journal • Infectious Disease • Pain

RWE Findings Demonstrate Benefits with Tanruprubart over Current Standard of Care in Matched Patient Populations (GlobeNewswire) - "In the RWE study, tanruprubart showed a rapid increase in muscle function resulting in a sustained and more complete recovery compared to IVIg or PE: By Week 1, patients treated with tanruprubart showed approximately a ten-point improvement in muscle strength over patients treated with IVIg or PE, a clinically meaningful benefit as measured by Medical Research Council (MRC) sumscore and an indicator for future recovery potential; Patients treated with tanruprubart were approximately three times more likely to be in a better state of health than patients on IVIg or PE on the GBS-Disability Scale (GBS-DS) at Weeks 4, 8, and 26."

Real-world evidence • Immunology

New Pivotal Phase 3 Trial Analyses Reinforce the Rapid and Sustained Clinical Benefits of a Single Dose of Tanruprubart (GlobeNewswire) - P3 | N=242 | NCT04701164 | Sponsor: Annexon, Inc. | "Tanruprubart 30 mg/kg halted inflammation and nerve damage resulting in clinical benefits as early as Week 1, including rapid improvements in muscle strength, mobility, balance, and coordination that were maintained through Week 26; Tanruprubart-treated patients rapidly regained the ability to move independently, do personal tasks, and return to a range of routine daily living activities; Tanruprubart demonstrated a greater degree of efficacy amongst patients with disease characteristics more commonly observed in western countries, supporting the potential of tanruprubart to benefit patients worldwide."

P3 data • Immunology

Annexon Reports First Quarter 2025 Financial Results, Portfolio Progress and Key Anticipated Milestones (GlobeNewswire) - "FDA Meeting for Tanruprubart (formerly ANX005), the First Potential Targeted Therapy for GBS, Scheduled for Second Quarter 2025 Ahead of Planned BLA Submission; Open-Label Tanruprubart FORWARD Study Designed to Broaden Patient and Healthcare Community Experience in North America and Europe, Initiating in Second Quarter 2025; Accelerated Enrollment in Phase 3 ARCHER II Trial on Pace for Completion in Third Quarter 2025 for ANX007, the First Potential Treatment for Dry AMD with GA; Pivotal Topline Data Expected in the Second Half of 2026."

FDA event • New trial • P3 data: top line • Age-related Macular Degeneration • Immunology

Annexon Highlights Pivotal Data on First Potential Targeted Therapy for Guillain-Barré Syndrome (GBS) and Showcases New GBS Education Campaign at American Academy of Neurology (AAN) 2025 Annual Meeting (GlobeNewswire) - P3 | N=242 | NCT04701164 | Sponsor: Annexon, Inc. | "New efficacy findings consistently demonstrated rapid recovery and durable benefits of tanruprubart across muscle strength, mobility and disability measures: At Week 1, treated patients rapidly gained motor function and were 14-fold more likely to perform the Timed Up and Go (TUG) test, a standardized measure of mobility, balance and lower limb capacity; At Week 1, treated patients rapidly gained motor ability and showed more than a 2-point improvement on the Overall Neuropathy Limitation Scale (ONLS), a tool used to assess limitations in everyday activities of the upper and lower limbs....The new findings build upon previously reported Phase 3 trial results that showed an improvement in the primary endpoint of GBS-DS at Week 8, as well as that twice the number of patients treated with tanruprubart fully recovered to normal (GBS-DS = 0) at Week 26, compared to placebo."

P3 data • Immunology

Annexon Announces Presentations on the Clinical Advancement of Tanruprubart as the First Potential Targeted Therapy for Guillain-Barré Syndrome (GBS) at the 2025 PNS Meeting (GlobeNewswire) - "First Oral Presentation by the International Guillain-Barré Syndrome Outcomes Study (IGOS) of the Real-World Evidence (RWE) Results Showing Improved Outcomes with Tanruprubart (formerly ANX005) Compared to Current Standards of Care in Matched Patient Populations. New Analyses of Phase 3 Trial Highlight Tanruprubart’s Early and Durable Treatment Effect and Improvement in Quality of Life in Patients with GBS....Annexon, Inc....today announced oral and poster presentations highlighting improved outcomes with tanruprubart (formerly ANX005) at the 2025 Peripheral Nerve Society (PNS) Annual Meeting at the Edinburgh International Conference Centre being held May 17-20, 2025 in Edinburgh, UK."

Clinical data • P3 data • Immunology