A Study of STX-1150 in Participants With Elevated Low-Density Lipoprotein Cholesterol (LDL-C) (STX-1150-01)

February 24, 2026 updated by: Stephen Nicholls, Monash University

A Phase 1 Open-Label Single Ascending Dose (Part 1) and Single or Multi-Dose Expansion (Part 2) Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of STX-1150 in Participants With Elevated Low-Density Lipoprotein Cholesterol (LDL-C)

STX-1150 is an investigational therapy designed to lower LDL-C by silencing a gene called PCSK9 in the liver. STX-1150 does not edit or permanently change the gene. STX-1150 comprises an mRNA and guide RNA (gRNA) delivered via lipid nanoparticles (LNP) for intravenous infusion. The mRNA produces a protein that switches off the PCSK9 gene expression without altering the DNA sequence. This process leverages natural mechanisms that regulate gene activity.

The study will enroll up to 64 participants with elevated LDL-C across sites in Australia and New Zealand. The follow-up period will be up to 1- year post-treatment.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

STX-1150 is an investigational product designed to epigenetically silence the PCSK9 gene. It comprises an mRNA and a guide RNA (gRNA) delivered in a lipid nanoparticle (LNP) for intravenous (IV) infusion.

STX-1150 epigenetically silences the expression of the PCSK9 gene in the liver, thereby reducing circulating PCSK9 and LDL-C levels. The active components, an mRNA and a gRNA are encapsulated in lipid nanoparticles (LNPs) for targeted hepatic delivery. The gRNA precisely guides the complex to a specific locus within the PCSK9 gene promoter.

By reducing PCSK9 expression, STX-1150 prevents the degradation of LDL receptors (LDL-R), leading to increased LDL-R levels on hepatocytes and enhanced clearance of LDL-C from the bloodstream. This targeted and durable epigenetic silencing represents a promising therapeutic strategy for long-term LDL-C reduction, particularly benefiting patients with elevated LDL-C or a high risk for Atherosclerotic Cardiovascular Disease (ASCVD).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
64

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Australia
    • Victoria
      • Clayton, Victoria, Australia, 3168

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Elevated serum LDL-C with or without LDL-C lowering medication
  • Willing and able to give informed consent before initiation of any study-related procedures and willing to comply with all required study procedures

Exclusion Criteria:

  • Patients with history of an ASCVD event </= 6 months.
  • Any uncontrolled or serious disease, or any medical or surgical condition that may interfere with participation
  • Diagnosis of familial hypercholesterolemia
  • Active or history of liver disease
  • Previous treatment with PCSK9-inhibitor or other prior treatment within a specified timeframe
  • Clinically significant abnormal laboratory values

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Arm 1

Part 1: An open-label, single ascending dose will serve to identify the Dose-Limiting Toxicities (DLTs) and Optimal Biological Dose (OBD) of STX-1150.

Part 2: Following Part 1, an open-label, single or multi-dose expansion of the OBD cohort will be conducted to further characterize the effect of STX-1150 and obtain additional safety data at the OBD.
Drug: STX-1150
Drug: STX-1150 is an investigational product designed to epigenetically silence the PCSK9 gene. Epigenome modulation offers a way to silence genes without changing their underlying DNA sequence.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Incidence and Severity of Treatment-Emergent Adverse Events (TEAEs)
Time Frame: Up to Week 52 from administration of STX-1150
Up to Week 52 from administration of STX-1150
Incidence and Severity of Serious Adverse Events (SAEs)
Time Frame: Up to Week 52 from administration of STX-1150
Up to Week 52 from administration of STX-1150
Incidence and Severity of Adverse Events of Special Interest (AESI)
Time Frame: Up to Week 52 from administration of STX-1150
Up to Week 52 from administration of STX-1150

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Incidence of dose-limiting toxicities (DLTs)
Time Frame: Within 14 days from administration of STX-1150
Within 14 days from administration of STX-1150
Percent Change from Baseline in Plasma PCSK9 Concentration
Time Frame: Up to Week 52
Up to Week 52
Percent Change from Baseline in LDL-C
Time Frame: Up to 52 weeks
Up to 52 weeks
Plasma Concentrations of STX-1150 Lipid Components
Time Frame: Up to 52 weeks
Up to 52 weeks
Number of Participants with Treatment-Induced Immunogenicity
Time Frame: Up to 52 Weeks
Up to 52 Weeks
Absolute Change from Baseline in LDL-C
Time Frame: Up to 52 weeks
Up to 52 weeks
The Absolute Change from Baseline in Plasma PCSK9 Concentration
Time Frame: Up to Week 52
Up to Week 52

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Monash University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Scribe Therapeutics Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Stephen Nicholls, MBBS, FRACP, PhD, VHI

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 1, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 19, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 23, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STX-1150-01

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Conditions

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Dietary Supplements

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