The purpose of this study is to demonstrate that SYD985 [(vic-)trastuzumab duocarmazine] is superior to physician's choice in prolonging progression free survival.



Eligible Ages
Over 18 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Female patients with histologically-confirmed, unresectable locally advanced or metastatic breast cancer;
  • Patients should have had either progression during or after at least two HER2-targeting treatment regimens for locally advanced or metastatic disease or progression during or after (ado-)trastuzumab emtansine treatment for locally advanced or metastatic disease;
  • HER2-positive tumor status;
  • Patients must have measurable or non-measurable disease that is evaluable per RECIST 1.1;
  • Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2;
  • Estimated life expectancy > 12 weeks at randomization;
  • Adequate organ function and blood cell counts.


Exclusion Criteria

  • Current or previous use of a prohibited medication as listed in the protocol;
  • History of infusion-related reactions and/or hypersensitivity to trastuzumab, (ado-)trastuzumab emtansine;
  • History of keratitis;
  • Severe, uncontrolled systemic disease at screening;
  • Left Ventricular Ejection Fraction (LVEF) < 50%, or a history of clinically significant decrease in LVEF during previous treatment with trastuzumab or (ado-)trastuzumab emtansine;
  • Cardiac troponin value above the Upper Limit of Normal (ULN);
  • History of clinically significant cardiovascular disease;
  • Untreated brain metastases, symptomatic brain metastases, brain metastases requiring steroids to manage symptoms, or treatment for brain metastases within 8 weeks prior to randomization;
  • History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitis obliterans), drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of active pneumonitis on screening chest CT scan.

Study Design

Phase 3
Study Type
Intervention Model
Parallel Assignment
Primary Purpose
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
(vic-)trastuzumab duocarmazine
SYD985, every 3 weeks (Q3W)
  • Drug: (vic-)trastuzumab duocarmazine
    Intravenous SYD985, Q3W
    Other names:
    • SYD985
    • Trastuzumab vc-seco-DUBA
Active Comparator
Physician's choice
Lap/Cap T/Cap T/Vino T/Eri
  • Drug: Physician's choice
    See drug label
    Other names:
    • Lapatinib (Lap)
    • Capecitabine (Cap)
    • Trastuzumab (T)
    • Vinorelbine (Vino)
    • Eribulin (Eri)

Recruiting Locations

University of Maryland Greenebaum Cancer Center
Baltimore, Maryland 21144

More Details

Byondis B.V.

Study Contact

Evelyn van den Tweel, PhD
+31 24 372 7700

Detailed Description

This study is designed as a randomized, active-controlled, superiority study in patients with unresectable locally advanced or metastatic HER2-positive breast cancer. The patients should have had either progression during or after at least two HER2-targeting treatment regimens for locally advanced or metastatic disease or progression during or after (ado-)trastuzumab emtansine treatment.

Eligible patients will be randomly assigned (2:1) to receive SYD985 or physician's choice treatment until disease progression, unacceptable toxicity or study termination by the Sponsor. During treatment, patients will have to visit the clinical site to assess efficacy, quality of life (QoL), and safety using standardized criteria.


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.