Recent Updates
Recently added Catalysts

zilganersen

Phase 3FDA approved

Alexander Disease | RNA therapy | Rare Disease |Ionis Pharmaceuticals, Inc.|Trials Updated: Aug 21, 2026

zilganersen development status

FDA approval on record Sep 3, 2026 as Zanvastro
Approval holderIonis Pharms Inc
ApplicationNDA220210
Highest phase Phase 3
Registered trials 2 across 1 sponsor since Apr 2021

zilganersen target and mechanism

Molecular targetGFAP
Target class-Sen (Aso)
ModalityRNA therapy

Also known as ION373

Success Probability

Subscribe to view

Market & Valuation

Subscribe to view

Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLED
Total Trials1
Total Enrollment54

FDA Designations

PRIORITY_REVIEWFAST_TRACKBREAKTHROUGH_THERAPY

zilganersen clinical trials

zilganersen · 1 trial · 1 indication

Phase 3 1
NCT04849741A Study to Evaluate the Safety and Efficacy of Zilganersen (ION373) in Patients With Alexander Disease (AxD)Alexander Disease
ACTIVE NOT_RECRUITING54 Analytics
PHASE3ACTIVE NOT_RECRUITING
A Study to Evaluate the Safety and Efficacy of Zilganersen (ION373) in Patients With Alexander Disease (AxD)
Alexander DiseaseUnlock trial analytics

Study Endpoints

Primary Endpoints

Percent Change from Baseline in the 10-Meter Walk Test (10MWT)
Baseline and Week 61

10-Meter Walk Test (10MWT) is an assessment of gait speed.

Secondary Endpoints

Change From Baseline in Most Bothersome Symptom (MBS)
Baseline and Week 61
Change From Baseline in Patient Global Impression of Severity (PGIS) Score
Baseline and Week 61
Change From Baseline in Patient Global Impression of Change (PGIC) Score
Baseline and Week 61
Unlock Study Endpoints

Study Design & Arms

AllocationRANDOMIZED
MaskingDOUBLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
zilganersenEXPERIMENTALZilganersen will be administered by intrathecal bolus (ITB) injection once every 12 weeks through Week 49. The 60-week double-blind treatment period will be followed by the open-label, long-term and extended long-term extension periods, where participants will receive zilganersen by ITB injection from Week 61 to Week 469.
PlaceboPLACEBO_COMPARATORMatching placebo will be administered by ITB injection once every 12 weeks through Week 49. It will be followed by the open-label, long-term and extended long-term extension periods, where participants will receive zilganersen by ITB injection from Week 61 to Week 469.

Interventions

NameTypeDescription
zilganersenDRUGzilganersen will be administered by ITB injection.
PlaceboDRUGzilganersen-matching placebo will be administered by ITB injection.
Unlock Study Design Details

Eligibility Criteria

Age Range2 Years to 65 Years
SexALL
Healthy VolunteersNo
Study Sites13

Key Inclusion Criteria: 1. Clinical phenotype and brain imaging consistent with a diagnosis of Alexander disease 2. Documented genetic mutation in the GFAP gene 3. Aged ≥ 2 to 65 years old at the time of informed consent 4. Able and willing to meet all study requirements, including travel to Study ...

Countries:United StatesAustraliaCanadaIsraelItalyJapanNetherlandsUnited Kingdom
Unlock Eligibility Criteria

Recent Changes (Last 90 Days)

MEDIUMAug 21, 2026NCT04849741Completion: 2029-09 → 2034-07
MEDIUMAug 21, 2026NCT04849741Completion: 2029-09 → 2034-07

Frequently asked questions about zilganersen

What is zilganersen used for?

Zilganersen is an investigational RNA therapy being developed for the treatment of Alexander Disease, a rare neurological disorder. It is not yet approved for any indication and remains in clinical development. The Phase 3 program is evaluating it in patients with Alexander Disease, including pediatric patients as young as 2 years old.

What does zilganersen target?

Zilganersen targets GFAP, or glial fibrillary acidic protein. It is an antisense oligonucleotide, part of the -sen chemical class, designed to reduce GFAP expression. GFAP is the protein that accumulates in Alexander Disease, so targeting it addresses the underlying cause of the condition rather than only its symptoms.

Who is developing zilganersen?

Zilganersen is being developed by Ionis Pharmaceuticals, Inc., which trades on the Nasdaq under the ticker IONS. Ionis is the sponsor of the clinical program studying the drug in Alexander Disease.

What phase is zilganersen in?

Zilganersen is in Phase 3 clinical development. It is an investigational drug and has not been approved by the FDA. The FDA has granted it Priority Review, Fast Track, and Breakthrough Therapy designations for Alexander Disease.

What clinical trials is zilganersen in?

Zilganersen is being studied in one active Phase 3 trial, NCT04849741, titled A Study to Evaluate the Safety and Efficacy of Zilganersen (ION373) in Patients With Alexander Disease. The trial is randomized, double-blind, and placebo-controlled, with an enrollment of 54 patients across the United States, Australia, Canada, Israel, Italy, Japan, the Netherlands, and the United Kingdom.

Is zilganersen the same as ION373?

Yes, zilganersen is also known as ION373. Both names refer to the same investigational antisense oligonucleotide developed by Ionis Pharmaceuticals for Alexander Disease. The Phase 3 trial NCT04849741 lists the drug under both names.