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Breast Cancer (Early Breast Cancer)SwithADCNCT07844291

A Prospective, Open-label, Randomized Trial Comparing Switch to A1811 Versus Continued THP Neoadjuvant Therapy After THP Induction in HER2-Positive Breast Cancer

A study testing A1811 and THP in people with Breast Cancer (Early Breast Cancer), run by Peking University People's Hospital.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Official record
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Trial summary

This is a multicenter, open-label, randomized controlled trial. A total of 432 eligible patients with HER2-positive breast cancer will be enrolled after screening. All patients will receive THP-based neoadjuvant therapy (THP) for 2 cycles. Read more about this study

Who is it for?
Ages 18 to 75 years, women only
Conditions the study is for
Breast Cancer (Early Breast Cancer)
What is being tested?
A1811 and THP
Could I receive a placebo?
No, everyone receives an active treatment
How many people
432 participants
Where
No sites listed yet
Study dates
1 Nov 2026to 31 Dec 2031
Phase
Interventional
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 18 to 75 years
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 1.18-75 years old 2.Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 3.HER2-positive breast cancer was defined by core needle biopsy pathology showing HER2 positivity, with IHC score of 3+ or IHC score 2+ with positive ISH results 4.At initial diagnosis, tumors were stage II-III according to the AJCC 8th edition breast cancer staging system and deemed operable 5.no prior history of any systemic anti-cancer therapy for breast cancer 6.Adequate organ function 7.Women of reproductive potential must have a negative pregnancy test prior to enrollment. Women of childbearing potential must commit to using effective contraception from study start until 6 months after the last dose of study medication, with ongoing assessment of adherence to contraception.
  • 8.All participants must voluntarily participate in this study and provide written informed consent, with consent approved by the ethics committee prior to use

Who cannot join

  • 1.Bilateral breast cancer, stage IV breast cancer, or inflammatory breast cancer; 2.Any history of malignancy within 5 years prior to signing informed consent, excluding treated cervical carcinoma in situ, non-melanoma skin cancer (basal cell carcinoma or squamous cell carcinoma) in remission; 3.Receiving anti-tumor therapy in another interventional clinical trial concurrently, including but not limited to chemotherapy, endocrine therapy, biologic therapy, bone-modifying agents, or immune checkpoint inhibitors; 4.Major surgery unrelated to breast cancer within 4 weeks prior to the first dose of study drug, or not yet fully recovered from such surgery; 5.Severe cardiac disease or unstable condition; 6.Uncontrolled active infections; history of immunodeficiency, including HIV-positive status, or other acquired or congenital immunodeficiency diseases, or a history of organ transplantation 7. Known hypersensitivity to any component of the study drug regimen; 8. Pregnant or breastfeeding women, women of reproductive potential with a positive baseline pregnancy test, or sexually active individuals not willing to use effective contraception from the time of enrollment through 6 months after the last study drug administration; 9.Known or suspected interstitial pneumonia; major or clinically significant pre-existing respiratory diseases within 3 months prior to first dose that could interfere with assessment of drug-related pulmonary toxicity or its management.
  • 10.urrently participating in another interventional pharmacologic clinical study; 11. Refusal to comply with follow-up procedures; 12. Presence of other serious medical or psychiatric conditions or laboratory abnormalities that may increase the risk of participation, interfere with study results, or for any other reason lead the investigator to believe the subject is not suitable for participation in this study.

About this study

Official title: Switching to A1811 vs. Continuation of the Original Neoadjuvant Regimen After THP Induction in HER2-Positive Breast Cancer

This is a multicenter, open-label, randomized controlled trial. A total of 432 eligible patients with HER2-positive breast cancer will be enrolled after screening. All patients will receive THP-based neoadjuvant therapy (THP) for 2 cycles. After 2 cycles, imaging-based response will be assessed according to RECIST v1.1. Patients with a response or stable disease (PR or SD) will be randomized 1:1 into the experimental group or the control group. Randomization occurs after the 2-cycle assessment. Experimental group: Switch to A1811 therapy for 4 cycles. Control group: Continue the THP regimen for 4 cycles. After completing a total of 6 cycles of neoadjuvant therapy, all patients will undergo definitive surgical treatment for pathological assessment. Primary endpoint: Pathologic complete response (pCR).

Being tested
A1811, THP
Medical subject headings
Breast Neoplasms

What participants receive

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

  • A1811Drug

    Switch to A1811 therapy for 4 cycles

  • THPDrug

    Continue the THP regimen for 4 cycles

Study groups in NCT07844291
Study groupRoleWhat they receive
swithing to A1811ExperimentalSwitch to A1811 therapy for 4 cycles
Receives: Drug: A1811
THPActive comparatorContinue the THP regimen for 4 cycles
Receives: Drug: THP

What is being measured

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

  1. pCR

    After completion of neoadjuvant therapy, patients underwent definitive surgical resection; histopathological assessment of the hematoxylin and eosin-stained excised breast cancer specimens and all ipsilateral lymph node samples showed no residual invasive cancer.

    Measured: From enrollment to the end of treatment at 6 months

Secondary outcomes (5)

  1. ORR

    The proportion of subjects achieving CR or PR as the best tumor response during neoadjuvant therapy. The investigators will assess objective response rate (ORR) according to RECIST v1.1.

    Measured: From enrollment to the end of treatment at 6 months

  2. EFS

    Time from randomization to the first occurrence of any of the following events: disease progression prior to surgery, local or distant recurrence after surgery, or death from any cause.

    Measured: From enrollment to the end of treatment at 5 years

  3. OS

    he time from randomization to death from any cause.

    Measured: From enrollment to the end of treatment at 5 years

  4. AE rate

    AEs were graded according to NCI-CTCAE v5.0. Descriptive statistics were summarized by treatment group for: any AE, AEs ≥ Grade 3, SAEs, drug-related AEs, drug-related SAEs, AEs leading to dose modification, and AEs leading to discontinuation of therapy. For each category, the number of patients with at least one event and the proportion (with 95% CI) of the corresponding total evaluable patients in each group were reported.

    Measured: From enrollment to the end of treatment at 4 weeks

  5. RCB0/1

    Residual Cancer Burden (RCB) was calculated from the surgical specimen using the published MD Anderson RCB methodology, incorporating: (1) residual tumor bed size in the breast (cm), (2) invasive cancer cellularity (%), (3) in situ component (%), (4) number of positive axillary lymph nodes and the largest metastasis size (mm). The resulting continuous RCB index (0-11.9) was categorized into RCB classes (RCB I, II, III) according to established cutoffs. Calculations were performed using the MD Anderson RCB calculator or an equivalent validated implementation, with results reviewed by study pathologists

    Measured: From enrollment to the end of treatment at 4 weeks

Timeline

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

  1. First posted28 Sep 2026
  2. Study start1 Nov 2026 (estimated)
  3. Primary completion31 Dec 2031 (estimated)
  4. Study completion31 Dec 2031 (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
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
432 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07844291
Sponsor's protocol ID
MA-BC-II-154
Acronym
SwithADC
Status last verified
Sep 2026
First submitted
21 Sep 2026
Last updated
28 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing A1811 and THP in people with Breast Cancer (Early Breast Cancer), run by Peking University People's Hospital.

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 2 inclusion and 2 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: opening soon, as of the sponsor's last update on 28 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

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.

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?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

pCR (time frame: From enrollment to the end of treatment at 6 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07844291.

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 Sep 2026.

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