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Taking people in ThailandPhase 2/3

Tests RO7771950 against tucatinib in HER2-positive breast cancer

Compares RO7771950 with tucatinib, both with trastuzumab and capecitabine, in adults with HER2-positive breast cancer.

Key facts

Who runs it
Hoffmann-La Roche
Where
Bangkok, Khon Kaen, Lak Si, Songkhla, and Wachira Phayaban, ThailandSee the 6 sitesAlso in 25 other countries, 213 sites
Registry title
RO7771950 Versus Tucatinib in Combination With Trastuzumab and Capecitabine in People With Locally Advanced or Metastatic Breast Cancer That is Human Epidermal Growth Factor Receptor 2 (HER2)-Positive
Status
Recruiting
Phase
Phase 2/3
People taking part
650 people, planned
Started
21 May 2026
Expected to end
29 Sept 2032
Type of study
Interventional, 3 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • RO7771950
  • Tucatinib
  • Trastuzumab
  • Capecitabine
Record updated
5 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with HER2-positive breast cancer that has spread or cannot be removed by surgery, who already had anti-HER2 treatment. Brain spread is allowed.

Age
18 years or older.
Sex
Men and women can join.
Disease stage
HER2-positive breast cancer, confirmed by a central laboratory, that is locally advanced and inoperable or has spread (metastatic). Measurable disease is needed in stage 1; non-measurable disease is allowed in stage 2. Brain (CNS) spread or leptomeningeal spread, treated or untreated, is allowed.
Earlier treatment
At least one earlier anti-HER2 treatment for advanced or metastatic disease. Earlier anti-HER2 antibody-drug conjugate such as trastuzumab-deruxtecan (T-DXd) or trastuzumab emtansine (T-DM1) is required, with limited exceptions. A tyrosine kinase inhibitor (TKI) given before or after surgery is allowed only if finished more than 12 months before the cancer became advanced. TKI treatment for advanced or metastatic disease is not allowed.
Biomarker or test result
HER2-positive status confirmed by a central laboratory. Heart pumping function (LVEF) of 50% or more.

Main reasons for not taking part

  • Other anti-cancer treatment, or an investigational therapy, within 28 days before starting study treatment
  • Known active or untreated hepatitis B or C, or chronic liver disease
  • Significant heart disease or heart rhythm risk, such as heart failure (NYHA II or higher) or QT prolongation
  • Significant electrolyte problems, or a family history of sudden unexplained death or long QT syndrome
  • Strong CYP3A4 or CYP2C8 inhibiting or inducing drugs or herbal medicines, or coumarin-type blood thinners taken by mouth

The registry criteria, word for word

Show all 14 criteriaShow less

Who can take part

  • Pathologically documented locally advanced inoperable (LAI) or metastatic breast cancer (MBC) with confirmed HER2-positive status by central laboratory
  • Measurable disease as per by RECIST v1.1 in stage 1. Non-measurable disease allowed in stage 2
  • Previously treated (stable or progressive) or previously untreated CNS metastases, or leptomeningeal metastases
  • At least one prior line of anti-HER2-based therapy for LAI or metastatic disease
  • Prior anti-HER2 antibody-drug conjugate (ADC), such as trastuzumab-deruxtecan (T-DXd) or trastuzumab emtansine (T-DM1), in any treatment setting. Participants without prior ADC therapy may only be enrolled if approved standard-of-care (SOC) anti-HER2 ADC is not locally accessible at screening, or if there is a prospectively documented clinical contraindication
  • Prior tyrosine kinase inhibitor (TKI) in the (neo)adjuvant setting provided completion is > 12 months ahead of LAI occurrence. Prior treatment with TKIs for LAI/MBC is not permitted
  • Has protocol-defined adequate organ and bone marrow function
  • Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
  • Baseline left ventricular ejection fraction (LVEF) ≥ 50%

Who cannot take part

  • Concurrent anti-cancer treatment, or treatment with investigational therapy within 28 days prior to initiation of study treatment
  • Concomitant use of any drug or herbal medicine known to strongly inhibit or induce CYP3A4 or CYP2C8 activity, oral coumarin-derivative anticoagulants
  • Known active/untreated hepatitis B or C or chronic liver disease
  • Clinically significant cardiovascular disease or risk, including heart failure (New York Heart Association (NYHA) ≥ II), ischemic heart disease or recent coronary events/interventions, clinically significant arrhythmias or electrocardiogram (ECG) abnormalities, QT prolongation or risk of ventricular dysrhythmias, poorly controlled hypertension, peripheral arterial disease, dilated cardiomyopathy, or unstable angina
  • Clinically significant electrolyte abnormalities (e.g., hypokalemia, hypomagnesemia, hypocalcemia), or family history of sudden unexplained death or long QT syndrome

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • What did the tests on your tumour show about hormone receptors and the HER2 protein?
  • Have you already had any medicine for your cancer after it spread or became advanced?

Where in Thailand

Also in 25 other countries, 213 sites

  • Faculty of Med. Siriraj Hosp.Bangkok, ThailandTaking people
  • Ramathibodi HospitalBangkok, ThailandTaking people
  • Srinagarind Hospital, Khon Kaen UniKhon Kaen, ThailandTaking people
  • Chulabhorn HospitalLak Si, ThailandTaking people
  • Songklanagarind HospitalSongkhla, ThailandTaking people
  • Bangkok Metropolitan Administration Medical College and Vajira HospitalWachira Phayaban, ThailandTaking people

About the trial

What the trial wants to find out

The purpose of this study is to assess the efficacy and safety of RO7771950 in combination with trastuzumab and capecitabine, compared to tucatinib in combination with trastuzumab and capecitabine.

The 3 groups in the trial

  • Arm A - RO7771950 Dose Type 1Treatment being tested

    Treatment: RO7771950, Trastuzumab, and Capecitabine

  • Arm B - RO7771950 Dose Type 2Treatment being tested

    Treatment: RO7771950, Trastuzumab, and Capecitabine

  • Arm C - TucatinibExisting treatment, for comparison

    Treatment: Tucatinib, Trastuzumab, and Capecitabine

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Two-part, Seamless, Multicenter, Randomized, Open-label, Adaptive Phase II/III Study of the Blood-brain Barrier Penetrant RO7771950 Versus Tucatinib, Both in Combination With Trastuzumab and Capecitabine, in Patients With Pretreated Unresectable Locally Advanced or Metastatic HER2-Positive Breast Cancer, With or Without Central Nervous System Metastases
Plain-language title
Tests RO7771950 against tucatinib in HER2-positive breast cancerGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Fit questions
Built from NCT07413939, who can take part
Record updated
5 November 2026