Recruiting
Phase 1
Phase 2

DS-3939a

Sponsor:

Daiichi Sankyo

Code:

NCT05875168

Conditions

Advanced Solid Tumor

Metastatic Solid Tumor

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

DS-3939a

Study Details

Brief summary:

This study will evaluate the safety, tolerability, and efficacy of DS-3939a in participants with advanced solid tumors.

Conditions

Advanced Solid Tumor

Metastatic Solid Tumor

Study ID

NCT05875168

Start date

Aug 18, 2023

Status verified date

Oct, 2026

Completion date

Nov 11, 2028

Anticipated

Primary completion date

Aug 11, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Sign and date the main Informed Consent Form (ICF).
  • Has a left ventricular ejection fraction ≥50% by either an echocardiogram or multigated acquisition within 28 days of enrollment.
  • Has adequate organ function.
  • Measurable disease based on RECIST V1.1.
  • Eastern Cooperative Oncology Group performance status score of 0 or 1.

Additional inclusion criteria for Part 1

  • Has a histologically or cytologically documented locally advanced, metastatic, or unresectable solid malignant tumors.

Additional inclusion criteria for Part 2

  • Has a histologically or cytologically documented locally advanced, metastatic, or unresectable cancer meeting the protocol criteria
  • Is able to provide either of the following baseline tumor samples:

1. Fresh tumor biopsy samples meeting either of the following requirements that were obtained during the Main Screening or Tissue Screening Period, or

  • Fresh core needle biopsy sample
  • Fresh biopsy samples obtained with forceps or cryobiopsy, such as bronchoscopic or transbronchial lung biopsy, or other procedures as long as the sample amount is equivalent to core needle biopsy and processing after sample collection follows the procedure described in the Study Laboratory Manual.
2. FFPE tumor tissue samples obtained by biopsy or surgery performed within 6 months before signing the main ICF. If samples were obtained prior to the start of the most recent anticancer therapy, the Sponsor Medical Monitor should be consulted regarding the adequacy of the sample.

Exclusion Criteria:

  • Has had prior treatment targeting mucin 1 (MUC1) or TA-MUC1.
  • Has spinal cord compression or clinically active central nervous system metastases.
  • Has multiple primary malignancies, except adequately resected non-melanoma skin cancer, curatively treated in situ disease, or other solid tumors curatively treated, with no evidence of disease for ≥3 years.
  • Has any history of ILD/pneumonitis irrespective of steroid use, or current ILD, or suspected ILD, or ILD that cannot be ruled out by imaging at Screening. Participants may be eligible if they had history of radiation pneumonitis that did not require steroids.
  • Has active or uncontrolled human immunodeficiency virus (HIV) infection.
  • Has evidence of active or uncontrolled hepatitis B virus or hepatitis C virus infection.
  • Any of the following within the past 6 months: cerebrovascular accident, transient ischemic attack, or other arterial thromboembolic event.
  • Has an active (ie, symptomatic and/or on-treatment), known, or suspected autoimmune disease.
  • Current participation in other therapeutic investigational procedures, except for participation in Long Term Follow-Up without any investigational treatment.

Study Design

Enrollment

590 participants

Anticipated

Allocation

Randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Dose Escalation (Part 1)

Participants with locally advanced, metastatic, or unresectable tumors who will receive an intravenous (IV) infusion of DS-3939a starting at 1 mg/kg.

experimental: Dose Expansion (Part 2)

Multiple expansion cohorts targeting various advanced solid tumors.

Interventions

DS-3939a

One IV infusion Q3W on Day 1 of each 21-day cycle

Primary outcome measure

  • Number of Participants with Dose-limiting Toxicities Following Treatment With DS-3939a [ Time Frame: Approximately 3 months after first dosing ]
  • Overall Number of Participants with Treatment-emergent Adverse Events and Serious Adverse Events Following Treatment With DS-3939a [ Time Frame: Up to approximately 31 months ]
  • Number of Participants with Objective Response Rate Following Treatment With DS-3939a (Part 2) [ Time Frame: Up to approximately 31 months ]
  • PSA50 Response Rate Following Treatment with DS-3939a (Part 2; CRPC only) [ Time Frame: Up to approximately 31 months ]

Central Contacts and Locations

Central contacts

(US Sites) Daiichi Sankyo Contact for Clinical Trial Information

908-992-6400CTRinfo@dsi.com

(Asia Sites) Daiichi Sankyo Contact for Clinical Trial Information

+81-3-6225-1111 (M-F 9-5 JST)dsclinicaltrial_jp@daiichisankyo.com

Locations

Florida Cancer Specialists

Recruiting

Sarasota, Florida, United States, 34232

University of Kansas Medical Center

Recruiting

Westwood, Kansas, United States, 66205

Astera Cancer Care

Recruiting

East Brunswick, New Jersey, United States, 08816

Oregon Health & Science University

Recruiting

Portland, Oregon, United States, 97239

Rhode Island Hospital

Recruiting

Providence, Rhode Island, United States, 02903

University of Texas M.D. Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

Huntsman Cancer Institute, University of Utah

Recruiting

Salt Lake City, Utah, United States, 84112

The Medical College of Wisconsin, INC

Recruiting

Milwaukee, Wisconsin, United States, 53226

Princess Margaret Cancer Center

Recruiting

Toronto, Canada, M5G2M9

More Information

Sponsor

Daiichi Sankyo

Last update posted

Oct 15, 2026

Last verified

Oct, 2026

Keywords

  • DS-3939a
  • Advanced/metastatic solid tumors
  • Antibody drug conjugate

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-23. This information was provided to ClinicalTrials.gov by Daiichi Sankyo on 2026-10-15. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.