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Fazirsiran Injection

Takeda · Phase 3 active Small molecule

Fazirsiran Injection is a RNAi therapeutic (siRNA) Small molecule drug developed by Takeda. It is currently in Phase 3 development for Transfusion-dependent beta-thalassemia, Iron overload disorders. Also known as: TAK-999, ARO-AAT, ADS-001, TAK-999, ARO-AAT, ADS-001.

Fazirsiran is an RNA interference (RNAi) therapeutic that silences the ALAS2 gene to reduce heme synthesis and iron accumulation in patients with iron overload disorders.

Fazirsiran is an RNA interference (RNAi) therapeutic that silences the ALAS2 gene to reduce heme synthesis and iron accumulation in patients with iron overload disorders. Used for Transfusion-dependent beta-thalassemia, Iron overload disorders.

Likelihood of approval
66.3% vs 58.3% industry baseline
If approved by FDA: likely 2028–2030
Steps remaining: NDA/BLA submission
Confidence: High
Why this estimate
  • Baseline phase 3 → approval rate +58.3pp
    Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
  • Rare-disease pathway favourability +5.0pp
    Rare-disease drugs benefit from FDA Orphan Drug Act, smaller pivotal trials, and more flexible endpoints. Approval rates run ~5pp above baseline.
  • Big-pharma sponsor +3.0pp
    Takeda is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2028–2030
EMA EU 2029–2031 +0.7 yr
MHRA GB 2029–2031 +0.7 yr
Health Canada CA 2029–2032 +0.9 yr
TGA AU 2029–2032 +1.2 yr
PMDA JP 2029–2032 +1.5 yr
NMPA CN 2030–2033 +2.3 yr
MFDS KR 2029–2032 +1.4 yr
CDSCO IN 2029–2033 +1.8 yr
ANVISA BR 2030–2033 +2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic nameFazirsiran Injection
Also known asTAK-999, ARO-AAT, ADS-001, TAK-999, ARO-AAT, ADS-001
SponsorTakeda
Drug classRNAi therapeutic (siRNA)
TargetALAS2 (aminolevulinic acid synthase 2)
ModalitySmall molecule
Therapeutic areaHematology / Rare Genetic Disorders
PhasePhase 3

Mechanism of action

Fazirsiran uses small interfering RNA (siRNA) technology to target and degrade ALAS2 messenger RNA, thereby decreasing aminolevulinic acid synthase 2 expression. This reduces heme production, which in turn decreases iron absorption and accumulation in tissues. The mechanism is designed to address the underlying pathophysiology of iron overload conditions by modulating the heme synthesis pathway.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Frequently asked questions about Fazirsiran Injection

What is Fazirsiran Injection?

Fazirsiran Injection is a RNAi therapeutic (siRNA) drug developed by Takeda, indicated for Transfusion-dependent beta-thalassemia, Iron overload disorders.

How does Fazirsiran Injection work?

Fazirsiran is an RNA interference (RNAi) therapeutic that silences the ALAS2 gene to reduce heme synthesis and iron accumulation in patients with iron overload disorders.

What is Fazirsiran Injection used for?

Fazirsiran Injection is indicated for Transfusion-dependent beta-thalassemia, Iron overload disorders.

Who makes Fazirsiran Injection?

Fazirsiran Injection is developed by Takeda (see full Takeda pipeline at /company/takeda).

Is Fazirsiran Injection also known as anything else?

Fazirsiran Injection is also known as TAK-999, ARO-AAT, ADS-001, TAK-999, ARO-AAT, ADS-001.

What drug class is Fazirsiran Injection in?

Fazirsiran Injection belongs to the RNAi therapeutic (siRNA) class. See all RNAi therapeutic (siRNA) drugs at /class/rnai-therapeutic-sirna.

What development phase is Fazirsiran Injection in?

Fazirsiran Injection is in Phase 3.

What are the side effects of Fazirsiran Injection?

Common side effects of Fazirsiran Injection include Injection site reactions, Transient liver enzyme elevations, Platelet count changes.

What does Fazirsiran Injection target?

Fazirsiran Injection targets ALAS2 (aminolevulinic acid synthase 2) and is a RNAi therapeutic (siRNA).

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing