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AzTrials

Metastatic Breast CancerPhase 3KATE3NCT04740918

A Study of Trastuzumab Emtansine in Combination With Atezolizumab or Placebo as a Treatment for Participants With Human Epidermal Growth Factor 2 (HER2)-Positive and Programmed Death-ligand 1 (PD-L1)-Positive Locally Advanced (LABC) or Metastatic Breast Cancer (MBC)

A Phase 3 study testing Trastuzumab Emtansine and Atezolizumab in people with Metastatic Breast Cancer, run by Hoffmann-La Roche at 51 sites in 19 countries.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
Search all trials

Trial summary

This study will evaluate the efficacy, safety and patient-reported outcomes of trastuzumab emtansine plus atezolizumab compared with trastuzumab emtansine plus placebo in participants with HER2-positive and PD-L1-positive LABC or MBC.Participants must have progressed either during or after prior trastuzumab- (+/… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Metastatic Breast Cancer
What is being tested?
Trastuzumab Emtansine and Atezolizumab
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
96 participants
Where
51 sitesin 19 countries
Study dates
7 Jun 2021to 19 Jun 2024
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • HER2+ and PD-L1+ locally advanced (LABC) or metastatic breast cancer (MBC)
  • Progression must have occurred during most recent treatment for LABC/MBC or during, or within 6 months after completing, neoadjuvant and/or adjuvant therapy
  • Prior treatment with trastuzumab (+/- pertuzumab) and taxane in the neoadjuvant and/or adjuvant, locally advanced, or metastatic setting
  • No more than two prior lines of therapy in the metastatic setting
  • Measurable disease per RESIST version 1.1
  • Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
Show all 10Show fewer
  • Life expectancy >= 6 months
  • Adequate hematologic and end-organ function
  • For women of childbearing potential: agreement to remain abstinent or use contraception, and agreement to refrain from donating eggs
  • For men: agreement to remain abstinent or use contraceptive measures, and agreement to refrain from donating sperm

Who cannot join

  • Prior treatment with trastuzumab emtansine in metastatic setting
  • History of exposure to cumulative doses of anthracyclines
  • Symptomatic or actively progressing central nervous system (CNS) metastases; asymptomatic CNS lesions ≤ 2cm without clinical requirement for local intervention or asymptomatic patients with treated CNS lesions are eligible
  • Current Grade >= 3 peripheral neuropathy
  • Cardiopulmonary dysfunction
  • History of malignancy within 5 years prior to initiation of study treatment, with the exception of the cancer under investigation and malignancies with a negligible risk of metastasis or death
Show all 12Show fewer
  • History of leptomeningeal disease
  • Active or history of autoimmune disease or immune deficiency
  • Active hepatitis B, hepatitis C and/or tuberculosis
  • Prior allogeneic stem cell or solid organ transplantation
  • Receipt of a live, attenuated vaccine within 4 weeks prior to initiation of study treatment, during treatment, or within 5 months following the last dose of study treatment
  • Pregnancy or lactation

Trial locations and contacts

51 sites in 19 countries.

51 sites in 19 countries

China10 sites
  • Peking University People's Hospital

    Beijing, 100044

  • Beijing Cancer Hospital

    Beijing, 100142

  • The First Hospital of Jilin University

    Changchun, 130021

  • Sun Yat-sen Memorial Hospital, Sun Yat-sen University

    Guangzhou, 510120

  • Zhejiang Provincial People's Hospital

    Hangzhou, 310014

  • Harbin Medical University Cancer Hospital

    Harbin, 150081

  • Jiangsu Province Hospital (the First Affiliated Hospital With Nanjing Medical University)

    Nanjing, 210029

  • Tianjin Medical University Cancer Institute & Hospital

    Tianjing, 300060

  • Union Hospital Tongji Medical College Huazhong University of Science and Technology

    Wuhan, 430023

  • Henan Cancer Hospital

    Zhengzhou, 450008

Other trials in China

Turkey (Türkiye)7 sites
  • Adana Baskent University Medical Faculty

    Adana, 01220

  • Sakarya Universitesi Egitim ve Arastirma Hastanesi

    Adapazari/Sakarya, 54100

  • Bakirkoy Dr. Sadi Konuk Egitim ve Arastirma Hastanesi, Tibbi Onkoloji

    Bakirkoy / Istanbul, 34147

  • Acibadem University School of Medicine Altunizade Hospital Oncology Service

    Istanbul, 34742

  • Katip Celebi University Ataturk Training and Research Hospital

    Izmir, 35360

  • Kayseri Acibadem Hospital

    Kayseri, 38000

  • Hacettepe Uni Medical Faculty Hospital

    Sihhiye/Ankara, 06230

Other trials in Turkey (Türkiye)

Brazil5 sites
  • Oncosite - Centro de Pesquisa Clinica Em Oncologia Ltda

    Ijuí, Rio Grande do Sul, 98700-000

  • Hospital do Cancer de Pernambuco - HCP

    Recife, Pernambuco, 50040-000

  • Hospital Sao Rafael - HSR

    Salvador, Estado de Bahia, 41253-190

  • Hospital de Base de Sao Jose do Rio Preto

    São José do Rio Preto, São Paulo, 15090-000

  • Núcleo de Pesquisa São Camilo

    São Paulo, São Paulo, 03102-002

Other trials in Brazil

Italy3 sites
  • Azienda Ospedaliera di Rilievo Nazionale e di Alta Specialita San Giuseppe Moscati

    Avellino, Campania, 83100

  • Azienda Ospedaliera S. Orsola-Malpighi

    Bologna, Emilia-Romagna, 40138

  • Istituto Nazionale Tumori Irccs Fondazione g. PASCALE

    Naples, Campania, 80131

Other trials in Italy

Philippines3 sites
  • Cebu Doctors' University Hospital

    Cebu City, 6000

  • St. Luke's Medical Center

    Quezon City, 1102

  • Cardinal Santos Medical Center

    San Juan City, 1502

Other trials in Philippines

United Kingdom3 sites
  • UCL Hospital NHS Trust

    London, NW1 2PG

  • Guys and St Thomas NHS Foundation Trust, Guys Hospital

    London, SE1 9RT

  • Nottingham University Hospitals City Campus

    Nottingham, NG5 1PB

Other trials in United Kingdom

Canada2 sites
  • Royal Victoria Hospital

    Barrie, Ontario, L4M 6M2

  • Centre Hospitalier de l?Université de Montréal (CHUM)

    Montreal, Quebec, H2X 0C2

Other trials in Canada

Colombia2 sites
  • Clinica Vida

    Medellín, DUMMY_VALUE

  • Oncomedica S.A.

    Montería, 230002

Other trials in Colombia

Croatia2 sites
  • Clinical Hospital Center Sestre Milosrdnice

    Zagreb, 10000

  • Clinical Hospital Centre Zagreb

    Zagreb, 10000

Other trials in Croatia

Finland2 sites
  • Helsinki University Central Hospital

    Helsinki, 00029

  • Tampere University Hospital

    Tampere, 33520

Other trials in Finland

Poland2 sites
  • Opolskie Centrum Onkologii

    Opole, 45-061

  • Centrum Onkologii ? Instytut im. Marii Sk?odowskiej-Curie Klinika Nowotworów Piersi i Chirurgii

    Warsaw, 02-781

Other trials in Poland

Portugal2 sites
  • Centro Hospitalar do Porto ? Hospital de Santo António

    Porto, 4099-001

  • IPO do Porto

    Porto, 4200-072

Other trials in Portugal

Spain2 sites
  • Hospital Universitario La Paz

    Madrid, 28046

  • Hospital Universitario Quiron Madrid

    Pozuelo de Alarcón, Madrid, 28223

Other trials in Spain

United States1 site
  • Emad Ibrahim, Md, Inc

    Redlands, California, 92373

Other trials in United States

Australia1 site
  • Peter MacCallum Cancer Center

    Melbourne, Victoria, 3000

Other trials in Australia

France1 site
  • Institut Curie - Hopital Rene Huguenin

    Saint-Cloud, 92211

Other trials in France

Norway1 site
  • Oslo Universitetssykehus HF

    Oslo, 0450

Other trials in Norway

Russia1 site
  • SBIH Republican Clinical Oncological Dispensary of the MoH of Republic Bashkortostan

    Ufa, Bashkortostan Republic, 450054

Other trials in Russia

South Korea1 site
  • Seoul National University Hospital

    Seoul, 03080

Other trials in South Korea

About this study

Official title: A Randomized, Multicenter, Double-Blind, Placebo-Controlled Phase III Study of the Efficacy and Safety of Trastuzumab Emtansine in Combination With Atezolizumab or Placebo in Patients With HER2-Positive and PD-L1-Positive Locally Advanced or Metastatic Breast Cancer Who Have Received Prior Trastuzumab- (+/- Pertuzumab) and Taxane-Based Therapy (KATE3)

This study will evaluate the efficacy, safety and patient-reported outcomes of trastuzumab emtansine plus atezolizumab compared with trastuzumab emtansine plus placebo in participants with HER2-positive and PD-L1-positive LABC or MBC.Participants must have progressed either during or after prior trastuzumab- (+/- pertuzumab) and taxane-based therapy for LABC/MBC; or during (or within 6 months after completing) trastuzumab- (+/-pertuzumab) and taxane-based therapy in the neoadjuvant and/or adjuvant setting.

Being tested
Trastuzumab Emtansine, Atezolizumab, Placebo
Medical subject headings
Breast Neoplasms

What participants receive

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

  • Trastuzumab EmtansineDrug

    Also called Kadcyla, T-DM1, RO5304020

    Trastuzumab emtansine 3.6 mg/kg IV infusion

  • AtezolizumabDrug

    Also called Tecentriq, RO5541267, MPDL3280A

    Atezolizumab 1200 mg IV infusion

  • PlaceboOther

    Placebo matched to atezolizumab

Study groups in NCT04740918
Study groupRoleWhat they receive
Arm A: Trastuzumab Emtansine and PlaceboActive comparatorPlacebo matched to atezolizumab followed by trastuzumab emtansine 3.6 milligrams per kilogram (mg/kg) intravenous (IV) infusion on Day 1 Cycle 1 and thereafter on Day 1 of each 21-day cycle until disease progression, unmanageable toxicity, or study termination by the sponsor.
Receives: Drug: Trastuzumab Emtansine; Other: Placebo
Arm B: Trastuzumab Emtansine and AtezolizumabExperimentalAtezolizumab 1200 mg IV infusion followed by trastuzumab emtansine 3.6 mg/kg IV infusion on Day 1 Cycle 1 and thereafter on Day 1 of each 21-day cycle until disease progression, unmanageable toxicity, or study termination by the Sponsor.
Receives: Drug: Trastuzumab Emtansine; Drug: Atezolizumab

What is being measured

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

  1. Progression-Free Survival (PFS) as Determined by Investigator Using Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1)

    PFS was defined as the time from randomization to the first occurrence of documented disease progression (PD), as determined by the investigator according to RECIST v1.1 or death from any cause whichever occurs first. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum in the study, including baseline, in addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 millimeter (mm). Median PFS was calculated using the Kaplan-Meier (KM) methodology. Data for participants without PD or death from any cause as of the data cut-off date were censored at the time of the last tumor assessment.

    Measured: Up to 28 months

  2. Overall Survival (OS)

    OS was defined as the time from the first dose of study treatment to the time of death from any cause. Participants who are alive as of the data cut-off date of the analysis were censored at the last known date they were alive. Participants with no post-baseline information were censored at the date of randomization plus 1 day. Median OS was calculated using the KM methodology.

    Measured: Up to 28 months

Secondary outcomes (7)
  1. Objective Response Rate (ORR)

    ORR was defined as the percentage of participants with complete response (CR) or partial response (PR) on two consecutive assessments, at least 28 days apart, as determined by the investigator using RECIST v.1.1. CR was defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) having a reduction in short axis to <10 mm. PR was defined as at least a 30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD. Only participants with measurable disease at baseline were analyzed for this outcome measure. Participants without a post-baseline tumor assessment were considered non-responders. An estimate of the ORR and its 95% CI (Wilson score confidence interval) were calculated for each treatment arm.

    Measured: Up to 28 months

  2. Duration of Response (DOR)

    DOR was calculated for participants who had a best OR of CR/PR. DOR was defined as time from first occurrence of a documented OR until the time of documented PD or death from any cause, whichever occurs first as determined by investigator assessment using RECIST v1.1. CR=the disappearance of all target lesions or any pathological lymph nodes (whether target or non-target) having a reduction in short axis to <10 mm. PR=at least a 30% decrease in the SOD of target lesions, taking as reference the baseline SOD. PD=at least a 20% increase in the SOD of target lesions, taking as reference the smallest sum on the study including baseline (nadir). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Median DOR was calculated using the KM methodology.

    Measured: Up to 28 months

  3. PFS in Participants With Baseline Brain Metastases as Determined by Investigator Assessment Using RECIST v1.1

    PFS was defined as the time from randomization to the first occurrence of documented PD, as determined by the investigator according to RECIST v1.1 or death from any cause whichever occurs first. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum in the study, including baseline, in addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Median PFS was calculated using the KM methodology.

    Measured: Up to 28 months

  4. OS in Participants With Baseline Brain Metastases

    OS is defined as the time from the first dose of study treatment to the time of death from any cause. Median OS was calculated using the KM methodology.

    Measured: Up to 28 months

  5. Central Nervous System (CNS) PFS as Determined by Investigator Using RECIST v1.1 in Participants With Baseline CNS Metastases

    CNS PFS was defined as the time from randomization to the first occurrence of documented CNS PD, or first occurrence of symptomatic CNS disease as determined by the investigator according to RECIST v1.1 or death from any cause whichever occurs first. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum in the study, including baseline, in addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Median PFS was calculated using the KM methodology. Participants who experienced non-CNS PD at the time of analysis were censored at the date of this progression. Participants who experienced no PD and were alive at the time of analysis were censored at date of their last post-baseline tumor assessment or, if they had no post-baseline tumor assessment, on the date of randomization + 1 day.

    Measured: Up to 28 months

  6. CNS PFS as Determined by Investigator Using RECIST v1.1 in Participants Without Baseline CNS Metastases

    CNS PFS was defined as the time from randomization to the first occurrence of documented CNS PD, or first occurrence of symptomatic CNS disease as determined by the investigator according to RECIST v1.1 or death from any cause whichever occurs first. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum in the study, including baseline, in addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Median PFS was calculated using the KM methodology. Participants who experienced non-CNS PD at the time of analysis were censored at the date of this progression. Participants who experienced no PD and were alive at the time of analysis were censored at date of their last post-baseline tumor assessment or, if they had no post-baseline tumor assessment, on the date of randomization + 1 day.

    Measured: Up to 28 months

  7. Percentage of Participants With Adverse Events (AEs)

    An AE was any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including abnormal laboratory values or abnormal clinical test results), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product.

    Measured: Up to 28 months

Timeline

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

  1. First posted5 Feb 2021
  2. Study start7 Jun 2021
  3. Primary completion19 Jun 2024
  4. Study completion19 Jun 2024

Why it stopped: Due to low enrollment, the Sponsor decided to prematurely terminate the study

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 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
96 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04740918
Sponsor's protocol ID
MO42319
Other IDs
2020-002818-41
Acronym
KATE3
Status last verified
Jul 2025
First submitted
3 Feb 2021
Last updated
8 Aug 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Trastuzumab Emtansine and Atezolizumab in people with Metastatic Breast Cancer, run by Hoffmann-La Roche at 51 sites in 19 countries.

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 10 inclusion and 12 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: stopped early, as of the sponsor's last update on 8 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 51 sites in China, Turkey (Türkiye), Brazil, Italy, Philippines and 14 more countries. 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?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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

Are results available for this study?

Yes. Results are posted in the registry (first posted 8 Aug 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Progression-Free Survival (PFS) as Determined by Investigator Using Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1) (time frame: Up to 28 months). 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 8 Aug 2025.

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