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Not yet recruitingNCT07545044Updated Apr 22, 2026

A Study of JSKN003 Versus Trastuzumab in Combination With Pertuzumab and Docetaxel as First-Line Treatment for HER2-Positive Recurrent or Metastatic Breast Cancer

A Phase 2 interventional study of JSKN003 and Trastuzumab in HER2-positive Recurrent or Metastatic Breast Cancer, sponsored by Shanghai JMT-Bio Inc.. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-22.

Sponsored by Shanghai JMT-Bio Inc. (part of CSPC Pharmaceutical Group Limited) · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

This study is a randomized, controlled, open-label, multicenter, phase II superiority clinical trial. The planned study population consists of participants with HER2-positive recurrent or metastatic breast cancer who have not previously received systemic therapy for advanced disease (participants who have undergone one prior endocrine treatment regimen are eligible for enrollment). The study aims to compare the efficacy and safety of JSKN003 versus trastuzumab combined with pertuzumab and docetaxel as first-line treatment for participants with HER2-positive recurrent or metastatic breast cancer.

Read the detailed description

Approximately 60 participants will be enrolled in this study and randomly assigned in a 2:1 ratio to receive either JSKN003 (experimental group) or trastuzumab combined with pertuzumab and docetaxel (control group). Randomization will be stratified by hormone receptor status (both estrogen receptor and progesterone receptor negative vs. estrogen receptor and/or progesterone receptor positive).

Hormone receptor-positive participants in the experimental group may receive concomitant endocrine therapy after completing six cycles of treatment. Participants who are intolerant to JSKN003 may continue treatment with its parental antibody, KN026. Hormone receptor-positive participants in the control group may receive concomitant endocrine therapy after discontinuation of docetaxel treatment. All participants will receive the study treatment as planned until disease progression, unacceptable toxicity, withdrawal of informed consent, loss to follow-up, or death, whichever occurs first.

02

Conditions studied

  • HER2-positive Recurrent or Metastatic Breast Cancer

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Keywords

  • breast cancer, HER2-positive, first-line treatment
03

In context

Breast Neoplasms

14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.

This study's planned enrollment of 60 is below the median of 72 across 10,896 interventional studies indexed under Breast Neoplasms.

Browse Breast Neoplasms studies →

Lead sponsor

Shanghai JMT-Bio Inc. is the lead sponsor of 42 studies on the registry; 29 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • 1Voluntary participation in this study and signing of the form (ICF).
  • Age ≥ 18 years.
  • and/or cytologically confirmed recurrent or breast cancer.
  • -positive tumor status confirmed by the central laboratory (Positive definition: IHC 3+, or IHC 2+ with positive ISH).
  • No prior systemic chemotherapy and/or HER2-targeted therapy for recurrent or metastatic disease. Participants who have received one prior endocrine therapy regimen are eligible. Participants who experienced recurrence more than 12 months after completing (neo) HER2-targeted therapy may be considered for enrollment.
  • (ECOG) performance status score of 0 or 1.
  • Presence of at least one per (RECIST) version 1.1.
  • Adequate organ and bone marrow function (without transfusion or use of hematopoietic growth factors for correction within 14 days prior to testing):

    1. (ANC) ≥ 1.5 × 10⁹/L, count ≥ 100 × 10⁹/L, ≥ 90 g/L.
    2. Hepatic function: Total (TBIL) ≤ 1.0 × (ULN); (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN (≤ 5 × ULN for participants with liver metastases); alkaline phosphatase (ALP) ≤ 2.5 × ULN.
    3. Renal function: ≥ 50 mL/min (calculated using the Cockcroft-Gault formula).
    4. Coagulation function: (INR) ≤ 1.5 and activated partial thromboplastin time (APTT) ≤ 1.5 × ULN. For participants receiving anticoagulant therapy, the investigator must deem both INR and APTT to be within a safe and effective therapeutic range.
    5. (LVEF) > 50%.
  • ≥ 3 months.
  • For female participants of , a negative serum pregnancy test result must be obtained within 7 days prior to randomization. Participants of childbearing potential or those with partners of childbearing potential must agree to use reliable and effective methods of during the study treatment period and for at least 7 months after the last dose of study treatment.

Exclusion criteria

Exclusion Criteria:

  • to trastuzumab, pertuzumab, and docetaxel, or deemed by the investigator as unsuitable for treatment with JSKN003.
  • Prior treatment with antibody-drug conjugates containing a topoisomerase I inhibitor (e.g., DS-8201, SHR-A1811, TQB-2102, etc.).
  • Toxicities from prior anti-tumor therapy have not recovered to ≤ Grade 1 per 6.0 (except for toxicities judged by the investigator to pose no safety risk, such as alopecia, peripheral neuropathy, or isolated laboratory abnormalities, which must have resolved to ≤ Grade 2).
  • During prior anti- therapy, (LVEF) decreased to \<50%, symptomatic congestive heart failure occurred, or toxicity leading to permanent treatment discontinuation was experienced.
  • Known and/or contraindications to (including but not limited to active peptic ulcer disease, severe hypertension, severe hypokalemia, glaucoma, etc.).
  • Use of strong inhibitors within 14 days prior to randomization.
  • History of hypersensitivity to any component of the drug(s) or any known .
  • Spinal cord compression or clinically active central nervous system (CNS) , defined as untreated or symptomatic, or requiring corticosteroids or anticonvulsants to manage related symptoms. Participants are eligible if they have been clinically stable for >4 weeks after treatment for without requiring corticosteroids or anticonvulsants and have recovered from acute toxicities of radiotherapy. Whole-brain radiotherapy or stereotactic radiosurgery must have been completed at least 2 weeks prior to study enrollment.
  • Active within 3 years prior to randomization, except for the breast cancer under investigation in this trial and any locally curable tumors that have undergone definitive treatment (e.g., resected basal cell or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix or breast, early-stage thyroid cancer, etc.).
  • Uncontrolled or significant cardiovascular or cerebrovascular diseases, including but not limited to:

    1. (NYHA) Class II or higher congestive heart failure, unstable angina, myocardial infarction, or arrhythmia causing hemodynamic instability within 6 months prior to randomization;
    2. Primary cardiomyopathy (e.g., dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, restrictive cardiomyopathy, unclassified cardiomyopathy);
    3. History of prolongation, or QTcF (calculated using Fridericia's formula) >480 ms during screening;
    4. Arterial/venous thrombotic events within 6 months prior to randomization, such as cerebrovascular accident (including , cerebral hemorrhage, cerebral infarction), deep vein thrombosis, and pulmonary embolism;
    5. Uncontrolled hypertension (systolic blood pressure >160 mmHg and/or diastolic blood pressure >100 mmHg).
  • History of (non-infectious) interstitial lung disease (ILD)/non-infectious pneumonitis requiring steroid treatment, current ILD/non-infectious pneumonitis, or suspected ILD/non-infectious pneumonitis that cannot be ruled out by imaging during screening.
  • Clinically significant pulmonary-specific comorbidities, including but not limited to any underlying pulmonary disease within 3 months prior to study enrollment, (e.g., pulmonary embolism, severe asthma, severe , restrictive lung disease, moderate to large pleural effusion, etc.).
  • Prior pneumonectomy.
  • Any documented , connective tissue, or inflammatory disease (e.g., rheumatoid arthritis, Sjögren's syndrome, sarcoidosis, etc.).
  • History of immunodeficiency, such as congenital immunodeficiency disease, organ transplantation, etc..
  • Uncontrolled active infection or disease, including but not limited to:

    1. Active or infection. Participants who are HBsAg positive and/or HCV antibody positive during screening must undergo HBV DNA and/or HCV RNA testing. Only participants with HBV DNA below the and/or negative HCV RNA are eligible;
    2. infection or history of AIDS;
    3. Known active tuberculosis;
    4. Active syphilis. Participants with positive TP-Ab during screening must undergo TRUST or RPR testing; participants positive for both are excluded;
    5. Other active infections or systemic use of anti-infective drugs for more than 1 week continuously within 28 days prior to randomization.
  • History of partial or complete intestinal obstruction, inflammatory bowel disease, chronic diarrhea, or gastrointestinal bleeding within 6 months prior to randomization.
  • Concurrent participation in another clinical study (except for non-interventional studies or the follow-up phase of an interventional study) or less than 4 weeks from the end of the previous clinical study (last dose) at the time of randomization.
  • Anti-tumor therapy including radiotherapy, targeted therapy, immunotherapy, and other investigational drugs within 28 days prior to randomization, or use of traditional Chinese medicine with anti-tumor indications within 14 days prior to randomization.
  • Uncontrolled serous cavity effusions (e.g., pleural effusion, ascites, pericardial effusion) requiring frequent drainage or medical intervention within 14 days prior to randomization, or requiring additional intervention within 2 weeks post-intervention (excluding cytological examination of effusion).
  • Major surgical procedures (e.g., abdominal, thoracic surgery; excluding minor procedures such as diagnostic puncture, infusion port placement, or biliary stent placement) within 28 days prior to randomization, or anticipated need for major surgery during the study period.
  • Women who are breastfeeding.
  • Any other condition that may interfere with the participant's ability to undergo study procedures, is not in the participant's best interest to participate, or may affect study outcomes: e.g., history of psychiatric disorders, drug or substance abuse, or any other clinically significant disease or condition.
Terms in these criteria, in plain language(38)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

HER2

HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.

In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.

Adjuvant and neoadjuvant

Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

INR, PT and aPTT (clotting tests)

Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.

Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

CTCAE grade

The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.

1
Mild.
2
Moderate.
3
Severe.
4
Life-threatening.
5
Death due to the event.

“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Brain metastases

Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).

Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

TIA (transient ischaemic attack)

A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.

Stroke symptoms need emergency care at once, even if they go away.

COPD

Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
60 participants (estimated)

Study arms

  • Experimental
    Experimental group

    JSKN003

    Drug: JSKN003

  • Active comparator
    Control group

    Trastuzumab + Pertuzumab + Docetaxel

    Drug: Trastuzumab · Drug: Pertuzumab · Drug: Docetaxel

Interventions

  • 6.3 mg/kg, IV, D1, Q3W

  • 8mg/kg loading dose, then 6mg/kg, IV, D1, Q3W

  • 840mg loading dose, then 420mg, IV, D1, Q3W

  • 75 mg/m2, IV, D1, Q3W for minimum of 6 cycles or until intolerable toxicity\[ym1.1\]\[z1.2\] or disease progression, whichever occurs first.

06

What researchers measure

Primary outcomes

  1. Overall Response Rate (ORR)

    ORR as Assessed by Investigator according to RECIST v1.1.

    Time frame: Up to 2 years

Secondary outcomes

  1. Progression-Free Survival (PFS)

    PFS as Assessed by Investigator according to RECIST v1.1.

    Time frame: Up to 2 years

  2. Disease Control Rate (DCR)

    DCR as Assessed by Investigator according to RECIST v1.1.

    Time frame: Up to 2 years

  3. Duration of Response (DoR)

    DoR as Assessed by Investigator according to RECIST v1.1

    Time frame: Up to 2 years

  4. Adverse Event (AE)

    Assess the incidence of all AE and serious adverse events (SAE).

    Time frame: Up to 2 years

  5. Plasma concentrations of JSKN003, total antibodies, and free toxin

    Tests are conducted according to the protocol.

    Time frame: Up to 2 years

  6. Incidence and titers of anti-drug antibodies (ADAs) to JSKN003, and incidence of neutralizing antibodies (NAbs, if applicable)

    Tests are conducted according to the protocol.

    Time frame: Up to 2 years

07

Study locations

No study locations are listed for this record.

08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 22, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT07545044
Responsible party
Sponsor
First posted
Apr 22, 2026
Start date
May 30, 2026 (estimated)
Primary completion
May 29, 2027 (estimated)
Completion
May 30, 2027 (estimated)
Last update
Apr 22, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is not yet recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.

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