Last reviewed · How we verify

ISIS-FXIRx Dose #2

Ionis Pharmaceuticals, Inc. · Phase 2 active Small molecule ✓ Verified Jun 2026 Quality 45/100

ISIS-FXIRx Dose #2 is a Antisense oligonucleotide anticoagulant Small molecule drug developed by Ionis Pharmaceuticals, Inc.. It is currently in Phase 2 development. Also known as: ISIS-FXIRx.

Antisense oligonucleotide that reduces production of factor XI, a clotting protein, to prevent thrombosis while minimizing bleeding risk.

ISIS-FXIRx Dose #2 is being studied in a clinical trial for its potential to treat End-stage Renal Disease (ESRD) and Venous Thromboembolism. The trial, NCT03358030, is evaluating the efficacy of ISIS 416858, a treatment that includes ISIS-FXIRx Dose #2, compared to a placebo.

Likelihood of approval
15.3% vs 15.3% industry baseline
If approved by FDA: likely 2031–2034
Steps remaining: Phase 3 → NDA/BLA submission
Confidence: Medium
Why this estimate
  • Baseline phase 2 → approval rate +15.3pp
    Industry-wide phase 2 drugs reach approval ~15.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2031–2034
EMA EU 2032–2035 +0.7 yr
MHRA GB 2032–2035 +0.7 yr
Health Canada CA 2032–2036 +0.9 yr
TGA AU 2032–2036 +1.2 yr
PMDA JP 2032–2036 +1.5 yr
NMPA CN 2033–2037 +2.3 yr
MFDS KR 2032–2036 +1.4 yr
CDSCO IN 2032–2037 +1.8 yr
ANVISA BR 2033–2037 +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 nameISIS-FXIRx Dose #2
Also known asISIS-FXIRx
SponsorIonis Pharmaceuticals, Inc.
Drug classAntisense oligonucleotide anticoagulant
ModalitySmall molecule
PhasePhase 2

Mechanism of action

ISIS-FXIRx uses antisense technology to bind to FXI messenger RNA, reducing the synthesis of factor XI protein in the liver. By lowering FXI levels, the drug inhibits the intrinsic coagulation pathway, providing anticoagulation with potentially lower bleeding risk than traditional anticoagulants that target other clotting factors.

Approved indications

Common side effects

No common side effects on file.

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 ISIS-FXIRx Dose #2

What is ISIS-FXIRx Dose #2?

ISIS-FXIRx Dose #2 is a Antisense oligonucleotide anticoagulant drug developed by Ionis Pharmaceuticals, Inc..

How does ISIS-FXIRx Dose #2 work?

Antisense oligonucleotide that reduces production of factor XI, a clotting protein, to prevent thrombosis while minimizing bleeding risk.

Who makes ISIS-FXIRx Dose #2?

ISIS-FXIRx Dose #2 is developed by Ionis Pharmaceuticals, Inc. (see full Ionis Pharmaceuticals, Inc. pipeline at /company/ionis-pharmaceuticals-inc).

Is ISIS-FXIRx Dose #2 also known as anything else?

ISIS-FXIRx Dose #2 is also known as ISIS-FXIRx.

What drug class is ISIS-FXIRx Dose #2 in?

ISIS-FXIRx Dose #2 belongs to the Antisense oligonucleotide anticoagulant class. See all Antisense oligonucleotide anticoagulant drugs at /class/antisense-oligonucleotide-anticoagulant.

What development phase is ISIS-FXIRx Dose #2 in?

ISIS-FXIRx Dose #2 is in Phase 2.

Related

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