Recent Updates
Recently added Catalysts

Olezarsen

Phase 3

Familial Chylomicronemia Syndrome | Small molecule | Other |Ionis Pharmaceuticals, Inc.|Last Updated: Dec 12, 2025

Success Probability
Approval Probability 71%
TA Base Rate26%
Adjusted LOA41%
ML RiskLOW_RISK
Premium
Market & Valuation
rNPV $3.2B
Market Size $9.4B
Revenue Basis $1.6B
Competitors 6
Premium
Trial Design
RandomizedDouble-BlindPLACEBO_CONTROLLEDDMCBiomarker
Total Trials3
Total Enrollment150
FDA Designations
PRIORITY_REVIEWORPHAN_DRUG
Clinical Trials (3)
NCT IDTitlePhaseStatusEnrollmentVelocityDesignStartCompletionLast UpdatedSitesCountries
NCT05185843A Study of Olezarsen (Formerly Known as AKCEA-APOCIII-LRX) Administered to Adults With Familial Chylomicronemia Syndrome (FCS) Previously Treated With VolanesorsenPHASE3 ACTIVE NOT_RECRUITING 24 — — Feb 25, 2022Jun 1, 2027Dec 12, 202511 United States, Canada +1
NCT05130450A Study of Olezarsen (Formerly Known as AKCEA-APOCIII-LRx) in Participants With Familial Chylomicronemia Syndrome (FCS)PHASE3 ACTIVE NOT_RECRUITING 60 — — Nov 18, 2021Feb 1, 2028Dec 12, 202527 United States, Canada +9
NCT04568434A Study of Olezarsen (Formerly Known as AKCEA-APOCIII-LRx) Administered to Patients With Familial Chylomicronemia Syndrome (FCS)PHASE3 COMPLETED 66 — — Nov 18, 2020Oct 17, 2023Mar 6, 202547 United States, Canada +9
Unlock Drug Trial Details
Study Endpoints
Primary Endpoints
Proportion of Participants With Decrease in Platelet Count by >30% or >50%, or With Platelet Count Value <50,000/cubic millimeter (mm^3)
Baseline to Week 209
Proportion of Participants With Clinical Bleeding Events
Baseline to Week 209
Proportion of Participants With Decrease in Estimated Glomerular Filtration Rate (eGFR) by ≥30% or ≥50%
Baseline to Week 209
Proportion of Participants With Urine Protein/Creatinine Ratio (UPCR) ≥1000 milligram (mg)/gram (g) or with Urine/Albumin Creatinine Ratio (UACR) ≥500 mg/g
Baseline to Week 209
Proportion of Participants With Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) ≥5 x Upper Limit of Normal (ULN)
Baseline to Week 209
Proportion of Participants With ALT or AST ≥3 x ULN and Total Bilirubin > 2 x ULN
Baseline to Week 209
Proportion of Participants With Total Bilirubin ≥2 mg/deciliter (dL)
Baseline to Week 209
Percent Change From Baseline in Fasting TG at 6 Months (Average of Weeks 23, 25, and 27) Compared to Baseline
Baseline and 6 months
Percent Change From Baseline in Fasting TG at Month 6
Baseline, Month 6
Secondary Endpoints
Trough (Pre-Dose) Plasma Concentration of Olezarsen
Up to 209 weeks
Post-Treatment Plasma Concentration of Olezarsen
Up to 209 weeks
Change and Percent Change From Baseline in Fasting Triglycerides (TG)
Baseline to Week 209
Unlock Study Endpoints
Study Design & Arms
AllocationNA
MaskingNONE
ModelSINGLE_GROUP
PurposeTREATMENT
Treatment Arms
ArmTypeDescription
OlezarsenEXPERIMENTALOlezarsen will be administered once every 4 weeks by subcutaneous (SC) injection for up to 209 weeks.
PlaceboPLACEBO_COMPARATORParticipants received olezarsen-matching placebo, once every 4 weeks by subcutaneous (SC) injection, during Weeks 1 to 49 of the 53-week treatment period.
Olezarsen 50 mgEXPERIMENTALParticipants received olezarsen, 50 milligrams (mg), once every 4 weeks by SC injection, during Weeks 1 to 49 of the 53-week treatment period.
Olezarsen 80 mgEXPERIMENTALParticipants received olezarsen 80 mg, once every 4 weeks by SC injection, during Weeks 1 to 49 of the 53-week treatment period.
Interventions
NameTypeDescription
OlezarsenDRUGOlezarsen will be administered by SC injection.
PlaceboDRUGOlezarsen-matching placebo was administered by SC injection.
Unlock Study Design Details
Eligibility Criteria
Age Range18 Years — N/A
SexALL
Healthy VolunteersNo
Study Sites11

Key Inclusion Criteria 1. Participants with FCS (clinical or genetic diagnosis) currently on or previously treated with volanesorsen (ISIS 304801) o Study participants in countries where Waylivra® is commercially approved and available for participants should not be deprived of the treatment op...

Countries:United StatesCanadaSwedenFranceItalyNetherlandsNorwayPortugalSlovakiaSpainUnited Kingdom
Unlock Eligibility Criteria
Recent Changes (Last 90 Days)
LOWMay 26, 2026NCT05130450primaryCompletionDate: changed
LOWMay 26, 2026NCT05185843primaryCompletionDate: changed
LOWMay 24, 2026NCT05130450studyFirstPostDate: changed
LOWMay 24, 2026NCT05185843studyFirstPostDate: changed