An open label clinical study to evaluate ANX005 (also known as tanruprubart) in participants with Guillain-Barré syndrome (FORWARD Study)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Annexon Inc.

Participant type

Pediatric, Patients

Age range

0-17 years, 18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Immune System Diseases [C20], Diseases [C] - Musculoskeletal Diseases [C05]

Trial duration

10 Dec 2025 → ongoing

Decision date (initial)

2025-11-11

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

No

Funding sources

Annexon

External identifiers

EU CT number

2025-522664-32-00

ClinicalTrials.gov

NCT07020819

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Safety, Pharmacokinetic, Pharmacodynamic, Efficacy

To characterize the PK profile of a single dose of ANX005 30 mg/kg in participants recently diagnosed with GBS from North America and Europe

Secondary objectives 2

1. To characterize the PD profile of a single dose of ANX005 30 mg/kg in participants recently diagnosed with GBS from North America and Europe
2. To compare the efficacy of a single dose of ANX005 30 mg/kg on muscle strength in participants recently diagnosed with GBS from North America and Europe relative to an external IGOS established benchmark.

Conditions and MedDRA coding

Guillain Barre Syndrome

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 8

1. Male or female aged 12 through 85 years at the time of signing the informed consent/assent
2. Diagnosis of GBS according to the National Institute of Neurological Disorders and Stroke (NINDS) Diagnostic Criteria for GBS
3. Onset of GBS-related weakness ≤10 days before infusion on Day 1
4. GBS-DS score of 3, 4, or 5 at Screening and before infusion on Day 1
5. If female at birth, must either be postmenopausal (no menses for ≥12 months without an alternative medical cause) or surgically sterilized; OR if of childbearing potential, use an acceptable method of contraception (Appendix 2) during the study and for at least 30 days after infusion with study drug
6. Agree not to use drugs of abuse during participation in the study and to undergo drug testing at Screening and at any time point during the study if drug abuse is suspected
7. Able to comply with the requirements of the study and complete the full sequence of protocol-related procedures and evaluations, including after hospitalization and at outpatient follow-up visits
8. Able to understand and provide written informed consent/assent (participant or participant’s legal representative/guardian)

Exclusion criteria 20

1. Clinically significant findings on the Screening electrocardiogram (ECG), laboratory test results, or physical examination that are not specific to GBS and that may interfere with the conduct of the study, the interpretation of the data, or increase risk to the participant
2. At risk of suicide or self-harm in the opinion of the Investigator
3. Body weight <30 or >150 kg at Screening
4. Unresponsive (inexcitable) nerve conduction study results in all nerves tested during Screening
5. Previous or planned treatment with either PE or IVIg within 90 days of Day 1. Note: Rescue treatment is allowed per protocol.
6. Current diagnosis of a variant of GBS, including Miller Fisher syndrome, Bickerstaff’s encephalitis, or overlap syndromes
7. Documented, clinically significant, pre-existing polyneuropathy from another cause (eg, diabetes mellitus [except mild sensory], alcoholism, severe vitamin deficiency, porphyria)
8. History of previous infusion reactions (ie, sensitivities or allergic or anaphylactic reactions to previous medication infusions)
9. Hypersensitivity to ANX005 or any of the excipients in the ANX005 drug product
10. Significant allergies to humanized monoclonal antibodies
11. History of a prior episode of GBS
12. Clinically significant uncontrolled intercurrent illness not associated with GBS that in the Investigator’s judgement could compromise the safety of the participant or interpretation of the data derived from the participant
13. History of autoimmune disorder (eg, rheumatoid arthritis, systemic lupus erythematosus)
14. Active meningitis, septicemia, or sepsis at Screening
15. Chronic use of corticosteroids (ie, >20 mg/day prednisone or equivalent) within 30 days before infusion on Day 1
16. Any known genetic deficiencies of the complement cascade system
17. Treatment with an unapproved investigational therapeutic agent within 30 days (or 5 half-lives for small molecule agents) before infusion on Day 1
18. Active alcohol or drug abuse, or any other reason that makes it unlikely that the participant will comply with study procedures. Participants with positive test results for 1 or more substances of abuse are not eligible to participate in the study.
19. Any participant who is pregnant (positive pregnancy test at Screening) or breastfeeding
20. Any participant expected to require immediate treatment with IVIg or PE based on status at presentation and/or likelihood for rapid deterioration per the mEGOS or risk for respiratory failure per the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS).

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Noncompartmental PK parameters of ANX005 in serum through Week 2

Secondary endpoints 2

1. Change from Baseline in free C1q protein concentration in serum through Week 2 • Change from Baseline in percent complement pathway activity in serum through Week 2
2. Medical Research Council (MRC) sumscore change from Baseline at Week 1

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Annexon Inc.

Sponsor organisation

Annexon Inc.

Address

1400 Sierra Point Parkway

City

Brisbane

Postcode

94005-1808

Country

United States

Scientific contact point

Organisation

Annexon Inc.

Contact name

Jamie Dananberg

Public contact point

Organisation

Annexon Inc.

Contact name

Jamie Dananberg

Third parties 1

Locations

3 EU/EEA countries · 5 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 25 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

6 submissions — initial application plus substantial / non-substantial modifications