A Phase 1/2 interventional study of DS-3939a in Advanced Solid Tumor and Metastatic Solid Tumor, sponsored by Daiichi Sankyo. Recruiting at 61 sites in 8 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by Daiichi Sankyo · Phase 1/2, Interventional, and Treatment
This study will evaluate the safety, tolerability, and efficacy of DS-3939a in participants with advanced solid tumors.
DS-3939a is an antibody drug conjugate (ADC) being developed for the treatment of malignant tumors. This is a first-in-human, dose-escalating clinical study divided into 2 parts: the Dose Escalation Part (Part 1) and the Dose Expansion Part (Part 2).
Additional inclusion criteria for Part 1
Additional inclusion criteria for Part 2
Is able to provide either of the following baseline tumor samples:
Fresh tumor biopsy samples meeting either of the following requirements that were obtained during the Main Screening or Tissue Screening Period, or
Exclusion Criteria:
Participants with locally advanced, metastatic, or unresectable tumors who will receive an intravenous (IV) infusion of DS-3939a starting at 1 mg/kg.
Drug: DS-3939a
Multiple expansion cohorts targeting various advanced solid tumors.
Drug: DS-3939a
One IV infusion Q3W on Day 1 of each 21-day cycle
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
Number of Participants with Objective Response Rate Following Treatment With DS-3939a (Part 1)
Time frame: Up to approximately 31 months
Disease Control Rate Following Treatment With DS-3939a
Time frame: Up to approximately 31 months
Duration of Response Following Treatment With DS-3939a
Time frame: Up to approximately 31 months
Time to Response Following Treatment With DS-3939a
Time frame: Up to approximately 31 months
Progression Free Survival Following Treatment With DS-3939a
Time frame: Up to approximately 31 months
Overall Survival Following Treatment With DS-3939a
Time frame: Up to approximately 31 months
TA-MUC1 Expression by Immunohistochemistry Following Treatment With DS-3939a
Time frame: At Cycle 1 Day 1
Area Under the Plasma Concentration Curve (AUC) Following Treatment With DS-3939a
Time frame: Cycles 1 & 3: Days 1, 2, 4, 8 & 15; Cycle 2: Day 1 & 1 time between Days 3 to 8 (Part 2 Only); Cycles 4 & every 2 cycles thereafter up to 31 months: Day 1 (each cycle is 21 days)
Maximum Plasma Concentration (Cmax) Following Treatment With DS-3939a
Time frame: Cycles 1 & 3: Days 1, 2, 4, 8 & 15; Cycle 2: Day 1 & 1 time between Days 3 to 8 (Part 2 Only); Cycles 4 & every 2 cycles thereafter up to 31 months: Day 1 (each cycle is 21 days)
Time to Maximum Plasma Concentration (Tmax) Following Treatment With DS-3939a
Time frame: Cycles 1 & 3: Days 1, 2, 4, 8 & 15; Cycle 2: Day 1 & 1 time between Days 3 to 8 (Part 2 Only); Cycles 4 & every 2 cycles thereafter up to 31 months: Day 1 (each cycle is 21 days)
Minimum Observed Concentration (Ctrough) Following Treatment With DS-3939a
Time frame: Cycles 1 & 3: Days 1, 2, 4, 8 & 15; Cycle 2: Day 1 & 1 time between Days 3 to 8 (Part 2 Only); Cycles 4 & every 2 cycles thereafter up to 31 months: Day 1 (each cycle is 21 days)
Terminal Half-Life (T1/2) Following Treatment With DS-3939a
Time frame: Cycles 1 & 3: Days 1, 2, 4, 8 & 15; Cycle 2: Day 1 & 1 time between Days 3 to 8 (Part 2 Only); Cycles 4 & every 2 cycles thereafter up to 31 months: Day 1 (each cycle is 21 days)
Number of Participants With Treatment-emergent Anti-drug Antibodies Following Treatment With DS-3939a
Time frame: Up to approximately 47 months
PSA50 Response Rate Following Treatment with DS-3939a (Part 1; CRPC only)
Time frame: Up to approximately 31 months
PSA30 and PSA90 Response Rate Following Treatment with DS-3939a (CRPC only)
Time frame: Up to approximately 31 months
Time to PSA Progression Following Treatment with DS-3939a (CRPC only)
Time frame: Up to approximately 31 months
Radiographic Progression-free Survival (PCWG 3) Following Treatment with DS-3939a (CRPC only)
Time frame: Up to approximately 31 months
Overall Survival Following Treatment with DS-3939a (CRPC only)
Time frame: Up to approximately 31 months
Plan to share: Yes — De-identified individual participant data (IPD) on completed studies and applicable supporting clinical trial documents may be available upon request at https://vivli.org/. In cases where clinical trial data and supporting documents are provided pursuant to our company policies and procedures, Daiichi Sankyo will continue to protect the privacy of our clinical trial participants. Details on data sharing criteria and the procedure for requesting access can be found at this web address: https://vivli.org/ourmember/daiichi-sankyo/
Supporting information: Study protocol, Sap, Icf
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