A Study of GEN1106 in Participants With Solid Tumors

First-In-Human, Open-Label, Dose Escalation and Expansion Trial to Evaluate the Safety, Pharmacokinetics and Efficacy of GEN1106 in Participants With Solid Tumors

The purpose of this trial is to learn about the safety and effectiveness of GEN1106 when it is used for the treatment of participants with certain types of cancer.

The trial has multiple parts. The first part of the trial tests different doses of GEN1106 to find out if it is safe and determine what are the best doses to use. The second and third parts continues to test the safety of and how well GEN1106 works in additional participants with a specific cancer type and at doses chosen based on results from the first part of the trial.

For each participant, the trial will last approximately 17 months but will vary for each person. This includes up to 21 days for screening prior to receiving trial treatment, approximately 5 months of treatment (the duration of treatment may vary for each participant), and approximately 11 months of follow up after trial treatment ends (the duration of follow up may vary for each participant).

Participation in the trial will require visits to the site, with more frequent visits during the first 6 weeks of treatment and then less frequent visits afterwards. At site visits, there will be various tests (such as blood draws) and procedures (such as recording of heart activity, computed tomography [CT] scans) to monitor whether the treatment is safe and effective.

All participants will receive active drug; no one will be given placebo.

Study Overview

• Status: Recruiting
• Conditions: Solid Tumors; Urothelial Carcinoma
• Intervention / Treatment: Biological: GEN1106

Detailed Description

This is a first-in-human (FIH), open-label, multicenter, dose escalation and expansion trial in participants with urothelial and other cancers who have metastatic disease to evaluate the safety, pharmacokinetics (PK), pharmacodynamics, and anti-tumor activity of GEN1106.

• Study Type: Interventional
• Enrollment (Estimated): 103
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Genmab Trial Information; Phone Number: +4570202728; Email: clinicaltrials@genmab.com

Study Locations

• Japan
  • Tokyo
    • Chuo Ku, Tokyo, Japan, 104-0045
      • Recruiting
      • National Cancer Center Hospital
• United States
  • New York
    • Lake Success, New York, United States, 11042
      • Recruiting
      • START New York Long Island LLC
  • South Carolina
    • Myrtle Beach, South Carolina, United States, 29572
      • Recruiting
      • Carolina Urologic Research Center
  • Texas
    • San Antonio, Texas, United States, 78229
      • Recruiting
      • South Texas Accelerated Research Therapeutics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

• Have progressed on or after standard of care (SoC) therapy, which should include chemotherapy, anti-programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) therapies, and enfortumab vedotin (EV), if applicable for the tumor type, or for whom there is no available standard therapy likely to provide clinical benefit, and for whom experimental therapy with GEN1106 may be beneficial, in the opinion of the investigator.
• Have measurable disease according to RECIST v1.1.
• Have Eastern Cooperative Oncology Group performance status (ECOG PS) score of 0 to 1 at screening.
• Part 1: Have histologically or cytologically confirmed diagnosis of cancer as specified per protocol.
• Parts 2 and 3: Have histologically or cytologically confirmed diagnosis of metastatic urothelial carcinoma (mUC).

Key Exclusion Criteria:

• Prior treatment with topoisomerase 1 inhibitor-based antibody-drug conjugate (ADC) therapy.
• Treatment with an anticancer agent within 4 weeks or for systemic therapies within 5 half-lives of the drug, whichever is shorter, prior to trial treatment administration.
• Has clinically significant toxicities from previous anticancer therapies that have not resolved to baseline levels or to grade 1 or lower, except for alopecia, anorexia, vitiligo, fatigue, hyperthyroidism, hypothyroidism, and peripheral neuropathy. Anorexia, hyperthyroidism, hypothyroidism, and peripheral neuropathy must have recovered to grade 2.

Note: Other protocol-defined Inclusion and Exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part 1: Dose Escalation; Groups of participants will receive 1 of 4 escalating dose levels of GEN1106.	Biological: GEN1106; Intravenous (IV) infusion.
Experimental: Part 2: Dose Refinement; Groups of participants will receive up to 3 dose levels of GEN1106 based on the dose escalation data.	Biological: GEN1106; Intravenous (IV) infusion.
Experimental: Part 3: Dose Expansion; Participants will receive up to 2 dose levels of GEN1106 based on the dose escalation / dose refinement data.	Biological: GEN1106; Intravenous (IV) infusion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Part 1 Dose Escalation: Number of Participants with Dose Limiting Toxicities (DLTs)	21 days
Part 1 Dose Escalation: Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)	Up to approximately 16 months
Part 2 Dose Refinement: Number of Participants with AEs and SAEs	Up to approximately 16 months
Part 3 Expansion: Objective Response Rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1	Up to approximately 16 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Part 1 Dose Escalation and Part 2 Dose Refinement: ORR per RECIST v1.1	Up to approximately 16 months
Part 3 Expansion: Number of Participants with AEs and SAEs	Up to approximately 16 months
Part 1 Dose Escalation and Part 2 Dose Refinement: Number of Participants with Antidrug Antibodies (ADA) to GEN1106	Up to approximately 5 months
Part 3 Expansion: Number of Participants with ADA to GEN1106	Up to approximately 5 months
Part 1 Dose Escalation and Part 2 Dose Refinement: Plasma Concentrations of GEN1106-related Analytes	Up to approximately 5 months
Part 3 Expansion: Plasma Concentrations of GEN1106-related Analytes	Up to approximately 5 months
Part 1 Dose Escalation and Part 2 Dose Refinement: Disease Control Rate (DCR) per RECIST v1.1	Up to approximately 16 months
Part 3 Expansion: DCR per RECIST v1.1	Up to approximately 16 months
Part 1 Dose Escalation and Part 2 Dose Refinement: Duration of Response (DOR) per RECIST v1.1	Up to approximately 16 months
Part 3 Expansion: DOR per RECIST v1.1	Up to approximately 16 months
Part 1 Dose Escalation and Part 2 Dose Refinement: Time to Response (TTR) per RECIST v1.1	Up to approximately 16 months
Part 3 Expansion: TTR per RECIST v1.1	Up to approximately 16 months

Collaborators and Investigators

• Sponsor: Genmab
• Investigators: Study Director: Study Official, Genmab

Study record dates

Study Major Dates

• Study Start (Actual): April 14, 2026
• Primary Completion (Estimated): April 5, 2029
• Study Completion (Estimated): June 25, 2029

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Carcinoma; Carcinoma, Transitional Cell
• Other Study ID Numbers: GCT1106-01; 2025-523760-21-00 (Ctis); jRCT2031260042 (Registry Identifier: Japan Registry of Clinical Trials)

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