Recruiting

Phase 1

Phase 2

XMT-1660A Study of Emiltatug Ledadotin (Emi-Le) in Participants With Solid Tumors

Sponsor:

Day One Biopharmaceuticals, Inc.

Code:

NCT05377996

Conditions

Triple Negative Breast Cancer

Breast Cancer

Endometrial Cancer

Ovarian Cancer

Fallopian Tube Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Emi-Le

Study Details

Brief summary:

A Study of Emi-Le in Participants with Solid Tumors

Conditions

Triple Negative Breast Cancer

Breast Cancer

Endometrial Cancer

Ovarian Cancer

Fallopian Tube Cancer

Study ID

NCT05377996

Start date

Aug 15, 2022

Status verified date

Jun, 2026

Completion date

Dec, 2027

Anticipated

Primary completion date

Feb, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

Recurrent or advanced solid tumor and has disease
Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
Participants in DES must have at least one measurable disease (target) lesion as defined by RECIST version 1.1.
Tumor tissue, either archival or from a fresh tumor biopsy, available for testing or be willing to undergo a minimally invasive tumor biopsy to obtain tumor tissue for local testing, if not medically contraindicated, prior to Cycle 1 Day 1
Brain magnetic resonance imaging (MRI) during the Screening period unless obtained within 30 days prior to Screening (based on standard clinical care), if they meet either of the following criteria:

1. All participants with TNBC
2. Participants with a history of brain metastases or with neurologic symptoms or signs suspicious for brain metastases.

Exclusion Criteria:

Prior treatment with an Antibody Drug Conjugate (ADC) containing an auristatin payload. Prior treatment with another ADC containing other payloads is allowed.
Major surgery within 28 days of starting study treatment, systemic anticancer therapy within the time period of 28 days or 5 half-lives of the prior therapy before starting study treatment (14 days or 5 half-lives for small molecule targeted therapy), whichever is less, or palliative radiation therapy to the chest within 3 months of starting study treatment or to other anatomic sites within 14 days of starting study treatment.
Diagnosis of additional malignancy that required active treatment (including surgery, systemic therapy, and radiation) within 2 years prior to screening, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ of the breast or of the cervix.
Untreated CNS metastases (including new and progressive brain metastases), history of leptomeningeal metastasis or carcinomatous meningitis.
Prior B7-H4 targeted treatment.
History of cirrhosis, hepatic fibrosis, esophageal or gastric varices, or other clinically significant liver diseases.
Current severe, uncontrolled systemic disease (e.g. clinically significant cardiovascular, pulmonary, or metabolic disease) or intercurrent illness that could increase the risk of serious adverse events (SAEs) or interfere with per-protocol evaluations, in the judgment of either the Sponsor or the Investigator.
Clinically significant cardiovascular disease
Active keratitis (inflammation of the cornea of the eye)

Study Design

Enrollment

360 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Emi-Le

Single arm Emi-Le alone (monotherapy)

Interventions

Emi-Le

Emi-Le will be administered through a vein in your arm or port catheter (intravenously)

Primary outcome measure

Frequency of adverse events that are considered dose-limiting toxicities (DLTs) and associated with Emi-Le during the first cycle of treatment (Dose Escalation) [ Time Frame: 17 months ]
Incidence of adverse events (Dose Escalation and Dose Expansion) [ Time Frame: 3 years ]
Objective Response Rate (ORR) (Dose Expansion and EMBLEM-1) [ Time Frame: approximately 3 years ]

Central Contacts and Locations

Central contacts

Day One Clinical Trials Information

1-650-484-0899 clinicaltrials@dayonebio.com

Locations

Mayo Clinic Comprehensive Cancer Center

Recruiting

Phoenix, Arizona, United States, 85054

Principal Investigator:

Felipe Batalini, MD

UC Irvine Health-Chao Family Comprehensive Cancer Center

Recruiting

Orange, California, United States, 92868

Principal Investigator:

Ritesh Parajuli

UCSF Helen Diller Family Comprehensive Cancer Center

Recruiting

San Francisco, California, United States, 94158

Principal Investigator:

Laura Huppert, MD

UCLA David Geffen School of Medicine, Division of Hematology/Oncology

Recruiting

Santa Monica, California, United States, 90404

Principal Investigator:

Nicholas McAndrew, MD

Mayo Clinic - Jacksonville

Recruiting

Jacksonville, Florida, United States, 32224

Principal Investigator:

Pooja Advani, MD

Florida Cancer Specialists

Recruiting

Sarasota, Florida, United States, 34232

Principal Investigator:

Judy Wang

Moffitt Cancer Center

Recruiting

Tampa, Florida, United States, 33612

Principal Investigator:

Hyo Han, MD

Winship Cancer Institute, Emory University

Recruiting

Atlanta, Georgia, United States, 30322

Northwestern University

Recruiting

Chicago, Illinois, United States, 60611

Principal Investigator:

Patricia Robinson, MD

Beth Israel Deaconess Medical Center

Recruiting

Boston, Massachusetts, United States, 02215

Principal Investigator:

Gerburg Wulf, MD

Dana-Farber Cancer Institute

Recruiting

Boston, Massachusetts, United States, 02215

Henry Ford Health Hospital

Recruiting

Detroit, Michigan, United States, 48202

Mayo Clinic - Rochester

Recruiting

Rochester, Minnesota, United States, 55905

Principal Investigator:

Roberto Leon-Ferre, MD

Comprehensive Cancer Centers of Nevada

Recruiting

Las Vegas, Nevada, United States, 89169

Principal Investigator:

Liawaty Ho, MD

New York University Langone Health

Recruiting

New York, New York, United States, 10016

ICHAN School of Medicine at Mount Sinai

Recruiting

New York, New York, United States, 10029

Principal Investigator:

Amy Tiersten

Memorial Sloan Kettering Cancer Center

Recruiting

New York, New York, United States, 10065

Stephenson Cancer Center Oklahoma University Health

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Principal Investigator:

Debra Richardson, MD

Avera Cancer Institute

Recruiting

Sioux Falls, South Dakota, United States, 57105

Principal Investigator:

David C. Starks, MD

Sarah Cannon Research Institute (SCRI)

Recruiting

Nashville, Tennessee, United States, 37203

Texas Oncology, P.A.

Recruiting

Dallas, Texas, United States, 75251

Principal Investigator:

Joyce O'Shaughnessy, MD

MD Anderson

Recruiting

Houston, Texas, United States, 77030

Principal Investigator:

Funda Meric-Bernstam

Huntsman Cancer Institute

Recruiting

Salt Lake City, Utah, United States, 84112

Principal Investigator:

Kristen Kelley, MD

NEXT Oncology Virginia

Recruiting

Fairfax, Virginia, United States, 22031

Fred Hutchinson Cancer Center

Recruiting

Seattle, Washington, United States, 09109

Summit Cancer Centers

Recruiting

Spokane, Washington, United States, 99208

More Information

Sponsor

Day One Biopharmaceuticals, Inc.

Last update posted

Jun 29, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Day One Biopharmaceuticals, Inc. on 2026-06-29.