New hope for Hard-to-Treat breast cancer: zanidatamab trial launches
NCT ID NCT06435429
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This phase 3 trial is testing whether a new drug called zanidatamab, given with chemotherapy, works better than the current standard treatment (trastuzumab plus chemo) for people with metastatic HER2-positive breast cancer that has worsened after prior therapy. About 550 adults will take part. The main goal is to see if the new combination delays cancer growth or improves survival.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- zanidatamab (a drug given by IV) combined with chemotherapy
- What this could lead to
- If it works, this could offer a new treatment option for people with HER2-positive breast cancer that has spread and stopped responding to current therapies.
- What could go wrong
- This is a large phase 3 trial, but the experimental drug may not improve survival or delay cancer growth compared to the standard treatment. Side effects from the drug combination are possible.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 3
Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.
- Participants
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About 550 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Aug 2024
- Expected to finish
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Oct 2030
An estimate. End dates often move.
- Lead sponsor
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A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 years and older
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Participants are eligible to be included in the study only if all of the following criteria apply: 1. Is 18 years of age or of the legal adult age per local standard at the time of signing the informed consent. 2. Has histologically confirmed HER2-positive breast cancer according to ASCO-CAP Guidelines as evaluated by a sponsor-designated central laboratory 3. Participants with unresectable or metastatic HER2 positive breast cancer who have progressed on, or are intolerant to, previous T-DXd treatment. 4. Must have received at least 2 lines of HER2-directed therapy for their metastatic disease. 1. Prior HER2-targeted neo-adjuvant or adjuvant therapy that resulted in relapse within 6 months of the completion of therapy will be considered a line of treatment for metastatic disease. 2. Based on the physician's choice, participants' eligibility, and institutional and local guidelines, participants may also have received post-T-DXd therapy, for example, a tucatinib-based regimen and/or T-DM1. 3. Participants must not have received more than 4 lines of HER2-directed therapy in the metastatic setting. 5. Has measurable disease per RECIST version 1.1. 6. Is eligible to receive one of the chemotherapy options listed in the physician's choice of chemotherapy (eribulin, gemcitabine, vinorelbine, or capecitabine). 7. Participants with history of treated or clinically inactive CNS metastases are eligible as specified in the protocol. 8. Has a life expectancy of at least 6 months, in the opinion of the investigator. 9. Has adequate hematologic parameters as defined in the protocol. 10. Has adequate hepatic function as specified in the protocol. 11. Has creatinine clearance ≥ 50 mL/minute as calculated per local institutional guidelines. 12. Has LVEF ≥ 50% as determined by either echocardiogram or MUGA obtained within 4 weeks before the first dose of study intervention. 13. Has ECOG performance status of 0 or 1. 14. Participant agrees to the following based on sex assigned at birth. 1. Male participants: Male participants are eligible to participate if they agree to the following during the study intervention period and for at least 7 months after the last dose of study intervention or the contraception period for the combination chemotherapy of choice per local guidance/standard practice: * Refrain from donating fresh unwashed semen. * Use contraception as follows as specified in the protocol 2. Female participants: * A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies: * Is a women of nonchildbearing potential OR * Is a woman of childbearing potential (WOCBP) and using a contraceptive method that is highly effective (with a failure rate of \< 1% per year), with low user dependency during the study intervention period and for at least 7 months after the last dose of study intervention. * A WOCBP must have a negative highly sensitive pregnancy test (urine or serum as required by local regulations) within 3 days before the first dose of study intervention. * Additional requirements for pregnancy testing during and after study intervention are provided in the protocol. * The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy. 15. Is capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and in the protocol. Participants are excluded from the study if any of the following criteria apply: Medical Conditions 1. Has clinically confirmed leptomeningeal disease, in the opinion of the investigator. 2. Has uncontrolled or significant cardiovascular disease. 3. Has toxicity related to prior cancer therapy that has not resolved to ≤ Grade 1, with exceptions as stated in the protocol. 4. Has uncontrolled infection requiring IV antibiotics, antivirals, or antifungals. 5. Has an infection with HIV-1 or HIV-2, with the exception of participants with well-controlled HIV. 6. Has active hepatitis B or C infection. 7. Has an active SARS-CoV-2 infection. Participants with prior infection that has resolved per local institutions' requirements and screening guidance are eligible. 8. Has a history of life-threatening hypersensitivity to monoclonal antibodies or to recombinant proteins or excipients in the drug formulation of zanidatamab. 9. Is unable to receive trastuzumab treatment due to medical contraindications. 10. Has any serious underlying medical or psychiatric condition that would impair the ability of the participant to receive or tolerate the planned treatment at the investigational site. 11. Has any condition that would prevent treatment with the physician's choice of chemotherapy. 12. Has any issue or condition that in the opinion of the investigator would contraindicate the participant's participation in the study or confound the results of the study. Prior/Concomitant Therapy 13. Has a history of prior allogeneic bone marrow, stem cell, or solid organ transplantation. 14. The washout periods for prior anticancer therapies before randomization as specified in the protocol. 15. Has a history of trauma or major surgery within 4 weeks prior to randomization. Other Exclusions 16. Has a known hypersensitivity to any components of the study drugs, including chemotherapy. 17. Female participants who are breastfeeding or pregnant, and female and male participants planning a pregnancy.
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Metastatic HER2-positive breast cancer are added.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
163 sites in 15 countries. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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AP HM Hopital de La Timone
RECRUITINGMarseille, 13005, France
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AZ Delta- Campus Rumbeke
RECRUITINGRoeselare, 8800, Belgium
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Abramson Cancer Center of The University of Pennsylvania
RECRUITINGPhiladelphia, Pennsylvania, 19104, United States
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Aichi Cancer Center
RECRUITINGNagoya, 464-8681, Japan
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Aretaieio Hospital
RECRUITINGAthens, 11528, Greece
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Arizona Oncology Tucson - Wilmot
WITHDRAWNTucson, Arizona, 85711, United States
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Asst Papa Giovanni Xxiii
RECRUITINGBergamo, 24127, Italy
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Athens Medical Center
RECRUITINGAthens, 15125, Greece
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Azienda Ospedaliero Universitaria Di Bologna Policlinico S Orsola Malpighi Via Massarenti
RECRUITINGBologna, 40138, Italy
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Azienda Ospedaliero Universitaria di Modena
RECRUITINGModena, 41124, Italy
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BC Cancer-Vancouver Center
RECRUITINGVancouver, V5Z 4E6, Canada
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Beatson West Of Scotland Cancer Centre
RECRUITINGGlasgow, G12 0YN, United Kingdom
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Białostockie Centrum Onkologii im. Marii Skłodowskiej-Curie w Białymstoku
RECRUITINGBialystok, 15-027, Poland
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Blue Ridge Cancer Care
RECRUITINGRoanoke, Virginia, 24014, United States
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Box Hill Hospital
RECRUITINGMelbourne, Victoria, 3128, Australia
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CHU UCL Namur - Site Sainte-Elisabeth
RECRUITINGNamur, 5000, Belgium
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CHU de Québec Université Laval Hôpital du Saint Sacrement
RECRUITINGQuébec, G1S 4L8, Canada
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CHUVI - H.U. Alvaro Cunqueiro
RECRUITINGVigo, 36312, Spain
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Catarina Pesquisa Clinica
RECRUITINGItajaí, 88301-220, Brazil
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Centre François Baclesse
RECRUITINGCaen, 14000, France
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Centre Georges François Leclerc
RECRUITINGDijon, 21000, France
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Centre Oscar Lambret
RECRUITINGLille, 59020, France
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Centro Regional Integrado de Oncologia
RECRUITINGCeará, 60336-232, Brazil
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Ceon Pesquisas Ltda
RECRUITINGSão Caetano do Sul, 09541-270, Brazil
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Charring Cross Hospital
RECRUITINGLondon, W6 8RF, United Kingdom
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Chiba Cancer Center
RECRUITINGChiba, 260-8717, Japan
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Churchill Hospital
RECRUITINGOxford, OX3 7LJ, United Kingdom
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Columbia University Medical Center 161 Fort Washington
RECRUITINGNew York, New York, 10032-3729, United States
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DASA Hospital Brasilia
RECRUITINGBrasília, 71.635-610, Brazil
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Dana Farber Cancer Institute
RECRUITINGBoston, Massachusetts, 02215-5418, United States
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Duke Cancer Institute
RECRUITINGDurham, North Carolina, 27710-2000, United States
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European Interbalkan Medical Center
RECRUITINGThessaloniki, 57001, Greece
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Florida Cancer Specialists Research East
RECRUITINGWest Palm Beach, Florida, 33401, United States
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Florida Cancer Specialists Research North
RECRUITINGSt. Petersburg, Florida, 33705, United States
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Florida Cancer Specialists Research South
RECRUITINGFort Myers, Florida, 33901, United States
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Fondazione IRCCS Policlinico San Matteo
RECRUITINGPavia, 27100, Italy
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Fondazione IRCCS San Gerardo dei Tintori
RECRUITINGMonza, 20900, Italy
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Fondazione Policlinico Universitario A. Gemelli IRCCS
RECRUITINGRome, 00136, Italy
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Fox Chase Cancer Center
RECRUITINGPhiladelphia, Pennsylvania, 19111, United States
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Fred Hutchinson Cancer Center
RECRUITINGSeattle, Washington, 98109, United States
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Froedtert and The Medical College of Wisconsin
RECRUITINGMilwaukee, Wisconsin, 53226, United States
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Fukushima Medical University Hospital
RECRUITINGFukushima, 960-1295, Japan
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Gachon University Gil Medical Center
RECRUITINGNamdong-gu, 21565, South Korea
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Gangnam Severance Hospital, Yonsei University Health System
RECRUITINGSeoul, 06273, South Korea
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Grand Hôpital de Charleroi
RECRUITINGGilly, 6060, Belgium
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Gustave Roussy
RECRUITINGVillejuif, 94800, France
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Guy's Hospital
RECRUITINGLondon, SE1 9RT, United Kingdom
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HPS Pharmacies - Adelaide
RECRUITINGAdelaide, 5000, Australia
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Hackensack Meridian Health
RECRUITINGHackensack, New Jersey, 07601, United States
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Helios Klinikum Berlin Buch GmbH Klinik für Gynäkologie und Geburtshilfe
RECRUITINGBerlin, 13125, Germany
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Hospital Beata Maria Ana
RECRUITINGMadrid, 28007, Spain
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Hospital Beneficiencia Portuguesa
RECRUITINGSão Paulo, 01323-030, Brazil
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Hospital Clinic de Barcelona
RECRUITINGBarcelona, 08036, Spain
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Hospital Clinico San Carlos
RECRUITINGMadrid, 28040, Spain
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Hospital Clínico Universitario de Valencia
RECRUITINGValencia, 46010, Spain
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Hospital General Universitario de Elche
RECRUITINGElche, 03203, Spain
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Hospital Nossa Senhora Da Conceição
RECRUITINGPorto Alegre, Rio Grande do Sul, 91350-200, Brazil
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Hospital Sao Lucas Da Pontificia Universidade Catolica Do Rio Grande Do Sul PUCRS
RECRUITINGPorto Alegre, 90610-001, Brazil
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Hospital Universitari Vall d Hebron
RECRUITINGBarcelona, 08035, Spain
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Hospital Universitario 12 de Octubre
RECRUITINGMadrid, 28041, Spain
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Hospital Universitario A Coruña
RECRUITINGA Coruña, 15006, Spain
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Hospital Universitario Clinico San Cecilio
RECRUITINGGranada, 18016, Spain
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Hospital Universitario Fundacion Jimenez Diaz
RECRUITINGMadrid, 28040, Spain
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Hospital Universitario Virgen del Rocio
RECRUITINGSeville, 41013, Spain
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Hospital Universitario de Badajoz
RECRUITINGBadajoz, 06006, Spain
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Hospital Universitario de Canarias
RECRUITINGSan Cristóbal de La Laguna, 38320, Spain
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ICANS - Institut de cancérologie Strasbourg Europe
RECRUITINGStrasbourg, 67000, France
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ICO Badalona-H.U. Germans Trias i Pujol
RECRUITINGBarcelona, 08916, Spain
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IEPE Unimed Sorocaba
RECRUITINGSorocaba, São Paulo, 18060-105, Brazil
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IRCCS Centro di Riferimento Oncologico di Aviano CRO
RECRUITINGAviano, 33081, Italy
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IRCCS Istituto Clinico Humanitas
RECRUITINGRozzano, 20089, Italy
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Institut Bergonie
RECRUITINGBordeaux, 33076, France
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Institut Paoli Calmettes
RECRUITINGMarseille, 13009, France
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Institute Jules Bordet
RECRUITINGAnderlecht, 1070, Belgium
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Irmandade Da Santa Casa de Misericordia de Porto Alegre
RECRUITINGPortalegre, 90050-170, Brazil
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Istituto Europeo di Oncologia
RECRUITINGMilan, 20141, Italy
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Istituto Oncologico Veneto - I.R.C.C.S.
RECRUITINGPadova, 35128, Italy
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Jewish General Hospital
RECRUITINGMontreal, H3T 1E2, Canada
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Juntendo University Hospital
RECRUITINGTokyo, 113-8431, Japan
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Kanagawa Cancer Center
RECRUITINGYokohama, 241-8515, Japan
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Klinikum Wels-Grieskirchen GmbH - Abteilung für Innere Medizin IV
RECRUITINGWels, 4600, Austria
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Kyoto University Hospital
RECRUITINGKyoto, 606-8507, Japan
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LMU Klinikum - Apotheke
RECRUITINGMünchen, 81377, Germany
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Leicester Royal Infirmary
RECRUITINGLeicester, LE2 7LX, United Kingdom
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Los Angeles Hematology Oncology Medical Group Glendale
RECRUITINGGlendale, California, 91204, United States
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MD Anderson Cancer Center
RECRUITINGMadrid, 28033, Spain
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Marienhospital Bottrop gGmbH
RECRUITINGDortmund, 44263, Germany
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Maryland Oncology Hematology Healing Way - USOR
RECRUITINGIrving, Texas, 75063, United States
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Mayo Clinic - PPDS
RECRUITINGRochester, Minnesota, 55905, United States
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Mayo Clinic Jacksonville - PPDS
RECRUITINGJacksonville, Florida, 32224, United States
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Mayo Clinic Scottsdale - PPDS
RECRUITINGPhoenix, Arizona, 85054, United States
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Medical Oncology Hematology Consultants
RECRUITINGIrving, Texas, 75063, United States
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Medizinische Universitat Innsbruck
RECRUITINGInnsbruck, 6020, Austria
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Medizinische Universitat Wien
RECRUITINGVienna, 1090, Austria
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Medstar Georgetown University Hospital
RECRUITINGWashington D.C., District of Columbia, 20007, United States
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Memorial Sloan Kettering
RECRUITINGLong Island City, New York, 11101, United States
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Messino Cancer Center
RECRUITINGAsheville, North Carolina, 28806, United States
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Millennium Research and Clinical Development
WITHDRAWNHouston, Texas, 77090, United States
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Minnesota Oncology Hematology
RECRUITINGCoon Rapids, Minnesota, 55433, United States
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Nagoya City University Hospital
RECRUITINGNagoya, 467-8602, Japan
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Narodowy Instytut Onkologii im. Marii Sklodowskiej-Curie Panstwowy Instytut Badawczy w Warszawie
RECRUITINGWarsaw, 02-781, Poland
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National Cancer Center Hospital
RECRUITINGChūōku, 104-0045, Japan
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National Hospital Organization Hokkaido Cancer Center
RECRUITINGSapporo, 003-0804, Japan
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National Hospital Organization Kyushu Cancer Center
RECRUITINGFukuoka, 811-1395, Japan
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National Hospital Organization Osaka National Hospital
RECRUITINGOsaka, 540-0006, Japan
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New Cross Hospital
RECRUITINGWolverhampton, WV10 0QP, United Kingdom
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Nexus Health
RECRUITINGIrving, Texas, 75063, United States
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Nucleo de Oncologia Da Bahia
RECRUITINGSalvador, 40.170-070, Brazil
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Okayama University Hospital
RECRUITINGOkayama, 700-8558, Japan
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Onco Star Sp Oncologia LTDA
RECRUITINGSão Paulo, 04062-001, Brazil
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Oncology Hematology Care (OHC)
RECRUITINGCincinnati, Ohio, 45226, United States
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Oncopôle Claudius Regaud Pharmacie
RECRUITINGToulouse, 31059, France
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Ordensklinikum Barmherzige Schwestern
RECRUITINGLinz, 4010, Austria
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Osaka International Cancer Institute
RECRUITINGChūōku, 541-8567, Japan
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Ospedale San Raffaele S.r.l PPDS
RECRUITINGMilan, 20132, Italy
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Peninsula and South Eastern Haematology and Oncology Group
RECRUITINGMount Waverly, Victoria, 3149, Australia
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Perlmutter Cancer Center 160 E 34th St
RECRUITINGNew York, New York, 10016-4744, United States
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Pharmacie Centre de Cancerologie de la Sarthe
RECRUITINGLe Mans, 72000, France
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Pharmacie ICM Val d'Aurelle
RECRUITINGMontpellier, 34298, France
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Pratia MCM Kraków
RECRUITINGKrakow, 30-727, Poland
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Pratia Poznan
RECRUITINGPoznan, 60-192, Poland
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Real Hospital Portugues de Beneficiencia Em Pernambuco
RECRUITINGRecife, 52.010-075, Brazil
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Rhode Island Hospital
RECRUITINGProvidence, Rhode Island, 02903, United States
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Rocky Mountain Cancer Centers
RECRUITINGDenver, Colorado, 80218, United States
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Royal United Hospital
RECRUITINGBath, BA1 3NG, United Kingdom
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Rutgers Cancer Institute of New Jersey
RECRUITINGNew Brunswick, New Jersey, 08901, United States
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Sagara Hospital
RECRUITINGKagoshima, 892-0833, Japan
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Saint Luke's Cancer Institute
RECRUITINGKansas City, Missouri, 64111, United States
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Saitama Medical University International Medical Center
RECRUITINGHidaka-shi, 350-1298, Japan
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Samsung Medical Center
RECRUITINGSeoul, 06351, South Korea
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Sansum Clinic 540 W - USOR
RECRUITINGIrving, Texas, 75063, United States
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Sarah Cannon Research Institute
RECRUITINGNashville, Tennessee, 37203, United States
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Seoul National University Bundang Hospital
RECRUITINGSeongnam-si, 13605, South Korea
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Seoul National University Hospital
RECRUITINGSeoul, 03080, South Korea
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Severance Hospital Yonsei University Health System
RECRUITINGSeoul, 03722, South Korea
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Showa University Hospital
RECRUITINGTokyo, 142-8666, Japan
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Soon Chun Hyang University Cheonan Hospital
RECRUITINGCheonan-si, 330721, South Korea
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St John of God Hospital Subiaco
RECRUITINGSubiaco, 6008, Australia
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Sunnybrook Research Institute
RECRUITINGToronto, M4N 3M5, Canada
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Sunshine Coast University Private Hospital
RECRUITINGBirtinya, Queensland, 4575, Australia
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Texas Oncology - Fort Worth
RECRUITINGFort Worth, Texas, 76104, United States
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Texas Oncology Gulf Coast
RECRUITINGIrving, Texas, 75063, United States
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Texas Oncology West
RECRUITINGIrving, Texas, 75063, United States
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The Catholic University of Korea, Seoul St. Mary's Hospital
RECRUITINGSeoul, 137-701, South Korea
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The Christie - PPDS
RECRUITINGManchester, M20 4BX, United Kingdom
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The Kinghorn Cancer Centre
RECRUITINGMount Kuring-Gai, 2080, Australia
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The Mount Sinai Hospital
RECRUITINGNew York, New York, 10029, United States
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The Oncology Institute Of Hope And Innovation
RECRUITINGCerritos, California, 90703, United States
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The Ottawa Hospital Cancer Centre
RECRUITINGOttawa, K1H 8L6, Canada
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Tokai University Hospital
RECRUITINGIsesaki-shi, 259-1193, Japan
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U.T. MD Anderson Cancer Center, Investigational Pharmacy Services
RECRUITINGHouston, Texas, 77030, United States
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UCSF at Mission Bay MB
RECRUITINGSan Francisco, California, 94158, United States
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UNC Central Investigational Drug Services
RECRUITINGMorrisville, North Carolina, 27560, United States
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USC-Norris Comprehensive Cancer Center - Investigational Drug Service IDS
RECRUITINGLos Angeles, California, 90033, United States
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UZ Antwerpen
RECRUITINGEdegem, 2650, Belgium
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University General Hospital of Patras
RECRUITINGPátrai, 26504, Greece
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University Hospitals Cleveland Medical Center 11100 Euclid Ave
WITHDRAWNCleveland, Ohio, 44106-1716, United States
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University of Arizona Cancer Center
RECRUITINGTucson, Arizona, 85719, United States
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University of Colorado-Cancer Center-PPDS
RECRUITINGAurora, Colorado, 80045-2517, United States
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Universitätsklinikum Carl Gustav Carus an der TU
RECRUITINGDresden, 01307, Germany
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Universitätsklinikum Ulm
RECRUITINGUlm, 89081, Germany
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Uniwersytecki Szpital Kliniczny w Poznaniu
RECRUITINGPoznan, 60-569, Poland
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Virginia Cancer Specialists
RECRUITINGFairfax, Virginia, 22031, United States
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Virginia Oncology Associates, Sentara Health
RECRUITINGNorfolk, Virginia, 23502, United States
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Washington Cancer Center
RECRUITINGWashington D.C., District of Columbia, 20010, United States
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Wojewódzki Szpital Specjalistyczny W Białej Podlaskiej
RECRUITINGBiała Podlaska, 21-500, Poland
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