NCT07182591 · Daiichi Sankyo
A Study of DS5361b in Participants With Advanced Solid Tumors
What this study is about
This study aims to assess the safety, tolerability, and preliminary effectiveness and to determine the MTD of DS5361b in treatment given alone and combination with pembrolizumab in participants with advanced or metastatic solid tumors.
View original scientific description
This study aims to assess the safety, tolerability, and preliminary efficacy and to determine the MTD of DS5361b in monotherapy and combination with pembrolizumab in participants with advanced or metastatic solid tumors.
Interventions
DRUG
DS5361b
Dose Escalation Part: DS5361b will be administered at escalating doses to determine the RDE. Dose Expansion Part: DS5361b will be administered at RDE.
DRUG
Pembrolizumab
Dose Escalation Part: Pembrolizumab will be administered at a standard dose. Dose Expansion Part: Pembrolizumab will be administered at a standard dose.
Primary outcome measures
Part 1 and 2: Number of participants with Dose-Limiting Toxicities (DLTs)
Time frame: Cycle 1: Day 1 up to Day 21 (each cycle is 21 days)
A DLT is defined as any Treatment Emergent Adverse Event (TEAE) not attributable to disease or disease-related processes, environmental factors, unrelated trauma, etc, that occurs during the DLT evaluation period (Day 1 to the end of Cycle 1) and is Grade ≥3.
Part 1, 2, and 3: Number of Participants Experiencing a Treatment Emergent Adverse Event (TEAE)
Time frame: From Screening up to approximately 5 years
TEAEs are defined as those Adverse Events (AEs) with start or worsening date during the on-treatment period (from the first dose date of trial intervention to 30 days after the last dose date of trial intervention).
Part 3 Only: Objective Response Rate (ORR) Following the Administration of DS5361b at RDE(s) in Combination with Pembrolizumab
Time frame: From first dose up to approximately 5 years
ORR is defined as the proportion of participants with a best overall response (BOR) of confirmed complete response (CR) or confirmed partial response (PR), as assessed by investigator per RECIST v1.1.
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
- The clinical site will screen for the full inclusion criteria per protocol.
- Adults ≥18 years of age at the time the ICF is signed (Please follow local regulatory requirements if the legal age of consent for trial participation is \>18 years old).
- Has histologically- or cytologically documented recurrent, metastatic, or unresectable solid tumors that are refractory to or intolerable with standard treatment or for which no standard treatment is available (For Part 1 and Part 2 only).
- Participants need to have documented TMB or MSI status using a validated or approved genomic test as per applicable regulations prior to Cycle 1 Day 1. In Part 1 and Part 2, participants need to have documented TMB-H and/or MSI-H status. In Part 3, participants need to have documented TMB-H status.
- Has measurable disease based on local CT/MRI imaging as assessment by the investigator using RECIST v1.1.
- Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1.
- Has adequate organ and bone marrow function as assessed by local laboratory within 14 days prior to initiation of trial intervention.
- For HNSCC participants only: have documented results from local testing of HPV for oropharyngeal cancer. If HPV status has previously been tested using this procedure, no retesting is required. Dose Expansion (Part 3) Only:
- Has histologically or cytologically confirmed, Stage IV NSCLC without actionable gene alteration.
- No prior systemic therapy.
- Participants with PD-L1 TPS ≥1%.
- Has histologically or cytologically confirmed recurrent or metastatic HNSCC that is considered incurable by local therapies.
- No prior systemic therapy administered in the recurrent or metastatic setting.
- Participants with PD-L1 CPS ≥1. Key
Exclusion criteria
- Has spinal cord compression or clinically active central nervous system metastases.
- Has a history of leptomeningeal carcinomatosis.
- Uncontrolled or significant cardiovascular disease.
- Any of the following within the past 6 months prior to enrollment: cerebrovascular accident, transient ischemic attack, or other arterial thromboembolic event.
- Has a history of (noninfectious) interstitial lung disease (ILD)/pneumonitis that required corticosteroids, has current ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out.
- Clinically severe pulmonary compromise (ie, requiring any supplemental oxygen).
- Has any evidence of severe or uncontrolled systemic diseases.
- Has active or uncontrolled HBV infection. Hepatitis B SCR testing is required.
- Has active or uncontrolled HCV infection. Hepatitis C SCR testing is required.
- For the dose escalation phase (Part 1 and Part 2), has HIV infection. For the dose expansion part (Part 3), has active or uncontrolled HIV infection.
- Prior organ transplantation, including allogeneic stem cell transplantation.
- Has an active, known, or suspected autoimmune disease.
- Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 14 days prior to the trial intervention.
Where
- Sarasota, Florida
- Providence, Rhode Island
- Irving, Texas
- San Antonio, Texas
- Fairfax, Virginia
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 14, 2026 · Source of record for eligibility and locations