A Trial to Investigate the Safety of E303 in Participants With Advanced Refractory Solid Tumors

August 25, 2026 updated by: Samsung Bioepis Co., Ltd.

A Phase I, Open-Label, Multi-Center, First-in-Human Trial to Investigate E303, in Participants With Advanced Refractory Solid Tumors

This is a Phase I trial to evaluate the safety, tolerability and efficacy of nectin-4 targeting antibody-drug conjugate (SBE303) in participants with advanced solid tumors

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

149

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Australia
      • Adelaide, Australia
        • Recruiting
        • Research Site
      • Melbourne, Australia
        • Recruiting
        • Research Site
  • South Korea
      • Seoul, South Korea
        • Not yet recruiting
        • Research Site
  • Spain
      • Barcelona, Spain
        • Recruiting
        • Research Site
      • Madrid, Spain
        • Recruiting
        • Research Site
  • United States
    • Arizona
      • Scottsdale, Arizona, United States, 85258
        • Recruiting
        • Research Site
    • Virginia
      • Fairfax, Virginia, United States, 22031
        • Recruiting
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Histologically-confirmed, locally advanced (unresectable) or metastatic solid tumors with recurrence or progression during or after standard therapy, intolerance to standard therapy, refused to receive standard therapy, or for whom no standard therapy is available.

Exclusion Criteria:

  • Have spinal cord compression or clinically active central nervous system metastases
  • Have leptomeningeal disease
  • Have thromboembolic or clinically significant bleeding events
  • Have significant cardiovascular disease
  • Have an active autoimmune disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: E303
Drug: E303
All participants will receive an intravenous (IV) infusion of E303

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of adverse events and serious adverse events
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Incidence of dose limiting toxicity
Time Frame: For the first cycle of treatment, through pre-dose Cycle 2 Day 1
For the first cycle of treatment, through pre-dose Cycle 2 Day 1
Confirmed objective response rate
Time Frame: 32 weeks
Efficacy endpoint per Blinded Independent Central Review (BICR), according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
32 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tumor response
Time Frame: 32 weeks
Efficacy endpoint per BICR, according to RECIST v1.1
32 weeks
Disease control rate
Time Frame: 32 weeks
Efficacy endpoint per BICR, according to RECIST v1.1
32 weeks
Area under the plasma/serum concentration vs time curve of total E303
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Maximum plasma/serum concentration of total E303
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Time to reach maximum plasma/serum concentration of total E303
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Plasma/serum concentration before the next dose of total E303
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Terminal half life of total E303
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Incidence and titer of anti-drug antibodies
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)
Incidence of neutralizing antibodies
Time Frame: Until trial completion (estimated 3 years)
Until trial completion (estimated 3 years)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Samsung Bioepis Co., Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 23, 2026

Primary Completion (Estimated)

July 1, 2030

Study Completion (Estimated)

July 1, 2030

Study Registration Dates

First Submitted

March 26, 2026

First Submitted That Met QC Criteria

April 6, 2026

First Posted (Actual)

April 13, 2026

Study Record Updates

Last Update Posted (Actual)

August 27, 2026

Last Update Submitted That Met QC Criteria

August 25, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • E303-1001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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