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HyperchylomicronemiaEarly Phase 1NCT07371767

CS-121 APOC3 Base Editing in Children and Adolescents With Hyperchylomicronemia

A Early Phase 1 study testing CS-121 in people with Hyperchylomicronemia, run by Shanghai Jiao Tong University School of Medicine at 1 site in China.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This is a Prospective, Single-center, Open-label, Single-arm Clinical Study to Evaluate the Safety and Efficacy of CS-121, an In Vivo Base Editing Therapy Delivered by Lipid Nanoparticles Targeting APOC3, in Children and Adolescents (4-18 years) With Hyperchylomicronemia Read more about this study

Who is it for?
Ages 4 to 18 years
Conditions the study is for
Hyperchylomicronemia
What is being tested?
CS-121
Could I receive a placebo?
No, everyone receives an active treatment
How many people
15 participants
Where
1 siteChina
Study dates
26 Jan 2026to 31 Jan 2041
Phase
Early Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 4 to 18 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • Male or female participants aged 4 years ≤ age < 18 years.
  • Severe hypertriglyceridemia (sHTG), defined as a triglyceride (TG) level ≥ 500 mg/dL.
  • Confirmed diagnosis of genetically inherited FCS via genetic testing, or clinically diagnosed FCS plus persistent chylomicronemia.
  • Failure to achieve adequate TG control, For participants under 8 years of age, the investigator determine at their discretion whether prior lipidlowering therapy has been administered.
  • Participants aged 6 years and above must sign the informed consent form themselves; for participants under 18 years of age, their parent/legal guardian must sign the informed consent form. (Participants under 6 years of age are exempt from signing the written informed consent form).
  • Female participants of childbearing potential must have a negative result on serum pregnancy testing.

Who cannot join

  • Currently participating in other interventional clinical studies, or having an insufficient washout period of less than 5 half-lives or 30 days (whichever is longer) since the last administration of other investigational drugs.
  • Used antisense oligonucleotide (ASO)-based or small interfering RNA (siRNA)-based lipid-lowering drugs targeting APOC3 within 3 months prior to study drug administration.
  • History of acute pancreatitis within 1 month before dosing.
  • Patients who underwent major surgery within 3 months prior to study drug administration and are judged by the investigator as unsuitable for receiving the study drug, due to potential intolerance to adverse events such as cytokine release storm.
  • ALT or AST ≥2 × ULN
  • Total bilirubin ≥1.5 × ULN
Show all 16Show fewer
  • eGFR <30 mL/min/1.73 m²
  • Random urine albumin-to-creatinine ratio (UACR) >30 mg/g, or urine protein is ≥ 2+
  • HbA1c ≥9%
  • Coagulation function abnormalities judged by the investigator as unsuitable for CS-121 administration.
  • Positive results for HBsAg, dual positivity for HCV antibody and RNA, positive for HIV, or positive for Treponema pallidum infection.
  • Known major organ diseases, mental disorders, Cushing's syndrome, hypothyroidism, history of lymphoproliferative disorders, or malignant tumors in any organ system, which are judged by the investigator as unsuitable for study participation due to potential intolerance to adverse events such as cytokine Release-Storm.
  • Concomitant medications/treatments judged by the investigator to affect lipid metabolism, liver and kidney function, coagulation function, or interfere with the efficacy evaluation of the study drug.
  • Patients of childbearing potential who are planning pregnancy, breastfeeding, or have fertility plans.
  • History of hypersensitivity to any study drug, its excipients, or drugs of similar chemical classes.
  • Other medical conditions or comorbidities that, in the investigator's opinion, may interfere with study compliance or data interpretation.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Guoying Chang, PhD contact

86+15000394881

changguoying@126.com

China1 site, 1 recruiting
  • Shanghai Children's Medical Center

    Shanghai, Shanghai Municipality

    Guoying Chang, PhD, 86+15000394881, changguoying@126.com

    Recruiting

Other trials in China

About this study

Official title: A Prospective, Single-center, Open-label, Single-arm Clinical Study to Evaluate the Safety and Efficacy of CS-121, an In Vivo Base Editing Therapy Delivered by Lipid Nanoparticles Targeting APOC3, in Children and Adolescents With Hyperchylomicronemia

This is a Prospective, Single-center, Open-label, Single-arm Clinical Study to Evaluate the Safety and Efficacy of CS-121, an In Vivo Base Editing Therapy Delivered by Lipid Nanoparticles Targeting APOC3, in Children and Adolescents (4-18 years) With Hyperchylomicronemia

Read the detailed description

CS-121 is an investigational, in vivo base editing therapy delivered by lipid nanoparticles (LNPs) targeting the APOC3 gene in the liver. By introducing precise base edits at specific APOC3 loci, CS-121 is intended to mimic naturally occurring protective mutations that reduce APOC3 expression, thereby restoring triglyceride clearance pathways and lowering pancreatitis risk. Preclinical studies in transgenic mouse and non-human primate models demonstrated dose-dependent APOC3 editing, reductions in serum ApoC3 protein and triglyceride levels, and acceptable safety profiles, supporting advancement into human evaluation. This open-label, single-arm, dose-escalation early exploratory trial designed to evaluate the safety, tolerability, PK/PD characteristics and preliminary efficacy of CS-121 in patients with hyperchylomicronemia. Based on the properties of gene editing therapy, the primary focus of the study is to identify the optimal biological dose (OBD) rather than the traditional maximum tolerated dose (MTD).

Being tested
CS-121
Keywords
Acute Pancreatitis, Apolipoprotein C3 (APOC3), In Vivo Base Editing, Lipid Nanoparticles (LNP), Gene Editing Therapy, Children and Adolescents
Medical subject headings
Hyperlipoproteinemia Type I, Pancreatitis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • CS-121Biological

    CS-121 is a in vivo base editing therapy formulated in lipid nanoparticles for targeted editing of the APOC3 gene in hepatocytes.

Study groups in NCT07371767
Study groupRoleWhat they receive
Low Dose CS-121ExperimentalParticipants in this arm will receive low dose of CS-121
Receives: Biological: CS-121
Middle Dose CS-121ExperimentalParticipants in this arm will receive middle dose of CS-121
Receives: Biological: CS-121
High Dose CS-121ExperimentalParticipants in this arm will receive high dose of CS-121
Receives: Biological: CS-121

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Dose-limiting toxicities (DLTs)

    Measured: Within 14 days post CS-121 dosing

  2. The incidence and severity of treatment-emergent adverse events (TEAEs)

    Measured: from screening to 10 months post last dosing

Secondary outcomes (3)
  1. Changes in serum triglyceride (TG) levels

    Measured: From baseline to 10 months post last dosing

  2. Changes in serum ApoC3 levels from baseline

    Measured: From baseline to 10 months post last dosing

  3. Concentrations of the active components of CS-121 (sgRNA and mRNA)

    Measured: From baseline to 1 month post last dosing

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Jan 2026
  2. Study start26 Jan 2026 (estimated)
  3. Primary completion31 Oct 2027 (estimated)
  4. Study completion31 Jan 2041 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Early Phase 1
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Sequential
Masking
None (open label)
Enrolment
15 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07371767
Sponsor's protocol ID
CS-121-02
Status last verified
Jan 2026
First submitted
19 Jan 2026
Last updated
28 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A Early Phase 1 study testing CS-121 in people with Hyperchylomicronemia, run by Shanghai Jiao Tong University School of Medicine at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 28 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Guoying Chang, PhD (86+15000394881, changguoying@126.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Dose-limiting toxicities (DLTs) (time frame: Within 14 days post CS-121 dosing). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jan 2026.

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