NCT06172478 · Daiichi Sankyo
A Study of HER3-DXd in Subjects With Locally Advanced or Metastatic Solid Tumors
What this study is about
This is a proof-of-concept study designed to investigate HER3-DXd treatment given alone in locally advanced unresectable or metastatic solid tumors.
View original scientific description
This is a proof-of-concept study designed to investigate HER3-DXd monotherapy in locally advanced unresectable or metastatic solid tumors. The study is enrolling cohorts of participants with melanoma \[cutaneous/acral\], squamous cell carcinomas of the head and neck (SCCHN), HER2-negative gastric cancer ovarian carcinoma, cervical cancer, endometrial cancer, bladder cancer, esophageal carcinoma, pancreatic carcinoma, prostate cancer, second-line gastric cancer, lung cancer, and breast cancer.
Interventions
DRUG
HER3-DXd
Intravenous infusion 5.6 mg/kg administered Q3W on Day 1 of each 21-day cycle
Primary outcome measures
Number of Participants With Objective Response Rate Assessed by Investigator Following HER3-DXd Monotherapy (All Cohorts Except Prostate Cancer Cohort)
Time frame: Baseline up until documented progressive disease, death, lost to follow-up, or withdrawal by the participant, up to approximately 27 months
Confirmed objective response rate (ORR) is defined as the sum of the complete response (CR) rate and partial response (PR) rate based on investigator by Response Evaluation Criteria In Solid Tumors (RECIST) v1.1.
Proportion of Participants Achieving a ≥50% Decrease in PSA (Prostate Cancer Cohort Only)
Time frame: Baseline, each cycle before infusion (each cycle is 21 days), and end of treatment, up to approximately 27 months
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants must meet all of the following criteria to be eligible for enrollment into the study: 1. Sign and date the informed consent form prior to the start of any study-specific qualification procedures. A separate tissue screening consent will be obtained from all subjects to meet the baseline tumor tissue requirement. 2. Participants aged ≥18 years (follow local regulatory requirements if the legal age of consent for study participation is \>18 years old). 3. Has locally advanced unresectable or metastatic disease (not curable by surgery or radiation) as follows: Cutaneous (acral and non-acral) melanoma 1. Histologically or cytologically confirmed cutaneous (acral or non-acral) melanoma 2. Disease progression while on or after having received treatment with ≥1 prior line of anti-programmed cell death protein (PD-1) or anti-programmed death-ligand 1 (PD-L1) based therapy (previous use of other immune checkpoint inhibitors \[ICIs\] \[ie, anti-CTLA4,
Where
- Duarte, California
- New Haven, Connecticut
- Kissimmee, Florida
- Chicago, Illinois
- Baltimore, Maryland
- Saint Louis Park, Minnesota
- Saint Paul, Minnesota
- St Louis, Missouri
- Buffalo, New York
- New York, New York
- Nashville, Tennessee
- Houston, Texas
And 1 more location — see the full list below.
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 15, 2026 · Source of record for eligibility and locations