Recruiting
Phase 1

XmAb541

Sponsor:

Xencor, Inc.

Code:

NCT06276491

Conditions

Ovarian Cancer

Endometrial Cancer

Germ Cell Tumor

Testicular Germ Cell Tumor

Ovarian Germ Cell Tumor

Eligibility Criteria

Sex: All

Age: 15+

Healthy Volunteers: Not accepted

Interventions

XmAb541

Study Details

Brief summary:

The primary purpose of this study is to determine whether the investigational drug XmAb541 is safe and well tolerated, and to determine an optimal and safe dose(s) for further study. The study will also evaluate the effect of XmAb541 on tumor outcomes.

Conditions

Ovarian Cancer

Endometrial Cancer

Germ Cell Tumor

Testicular Germ Cell Tumor

Ovarian Germ Cell Tumor

Study ID

NCT06276491

Start date

Apr 4, 2024

Status verified date

Aug, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 15+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Age ≥ 18 years. For US only: subjects with GCTs, age ≥15 years
  • CLDN6+ tumor
  • Histological or cytological documentation of locally advanced, recurrent, or metastatic ovarian, fallopian tube, or peritoneal cancer, adenocarcinoma of the endometrium (endometrial cancer, uterine cancer, or carcinoma of the uterine corpus), GCT resistant to previous treatment
  • Adequate Eastern Cooperative Oncology Group performance status
  • Life expectancy ≥ 3 months
  • Adequate liver, kidney, and bone marrow function

Key Exclusion Criteria:

  • Participants with untreated brain metastases are excluded. Participants with treated brain metastases may participate, provided they are radiologically stable.
  • Active known or suspected autoimmune disease
  • Have any condition requiring systemic treatment with corticosteroids, prednisone equivalents, or other immunosuppressive medications within 14 days prior to first dose of study drug
  • Clinically significant cardiovascular, pulmonary or gastrointestinal disease
  • Active hepatitis B or hepatitis C

Study Design

Enrollment

282 participants

Anticipated

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Dose escalation and Dose Expansion of XmAb541

Intravenous or Subcutaneous administration

Interventions

XmAb541

Monoclonal bispecific antibody

Primary outcome measure

  • Incidence of adverse events [ Time Frame: Day 1 to 2 years ]
  • Incidence of dose-limiting toxicities (DLTs) [ Time Frame: Day 1 to Day 28 ]
  • Incidence of cytokine release syndrome (CRS) [ Time Frame: Day 1 to Day 28 ]

Central Contacts and Locations

Central contacts

XmAb541-01 Central Contact

info541-01@xencor.com

Locations

City of Hope

Recruiting

Duarte, California, United States, 91010

Stanford

Recruiting

Palo Alto, California, United States, 94304

University of California

Recruiting

San Francisco, California, United States, 94158

Moffitt Cancer Center

Recruiting

Tampa, Florida, United States, 33612

Winship Cancer Institute, Emory University

Recruiting

Atlanta, Georgia, United States, 30322

University of Chicago Medical Center

Recruiting

Chicago, Illinois, United States, 60637

Indiana University Melvin and Bren Simon Comprehensive Cancer Center

Recruiting

Indianapolis, Indiana, United States, 46202

Karmanos Cancer Institute

Recruiting

Detroit, Michigan, United States, 48201

University of Minnesota

Recruiting

Minneapolis, Minnesota, United States, 55455

The John Theruer Cancer Center at Hackensack University Medical Center

Recruiting

Hackensack, New Jersey, United States, 07601

Icahn School of Medicine at Mount Sinai

Recruiting

New York, New York, United States, 10029

Montefiore Einstein Comprehensive Cancer Center

Recruiting

The Bronx, New York, United States, 10461

The Ohio State University

Recruiting

Columbus, Ohio, United States, 43210

OU Health Stephenson Cancer Center

Recruiting

Oklahoma City, Oklahoma, United States, 73104

UPMC Hillman Cancer Center

Recruiting

Pittsburgh, Pennsylvania, United States, 15232

SCRI Oncology Partners

Recruiting

Nashville, Tennessee, United States, 37203

University of Virginia

Recruiting

Charlottesville, Virginia, United States, 22903

More Information

Sponsor

Xencor, Inc.

Last update posted

Aug 25, 2026

Last verified

Aug, 2026

Keywords

  • Phase 1
  • Ovarian Cancer
  • CLDN6
  • Testicular Cancer
  • Germ Cell Tumor
  • Endometrial Cancer
  • T-cell Engager

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Xencor, Inc. on 2026-08-25.