NCT05377996

Brief Summary

A Study of XMT-1660 in Solid Tumors

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
319

participants targeted

Target at P75+ for phase_1

Timeline
12mo left

Started Aug 2022

Longer than P75 for phase_1

Geographic Reach
1 country

26 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress79%
Aug 2022May 2027

First Submitted

Initial submission to the registry

May 2, 2022

Completed
15 days until next milestone

First Posted

Study publicly available on registry

May 17, 2022

Completed
3 months until next milestone

Study Start

First participant enrolled

August 15, 2022

Completed
4.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2026

Expected
5 months until next milestone

Study Completion

Last participant's last visit for all outcomes

May 1, 2027

Last Updated

April 14, 2026

Status Verified

October 1, 2025

Enrollment Period

4.3 years

First QC Date

May 2, 2022

Last Update Submit

April 9, 2026

Conditions

Outcome Measures

Primary Outcomes (3)

  • Frequency of adverse events that are considered dose-limiting toxicities (DLTs) and associated with XMT-1660 during the first cycle of treatment (Dose Escalation)

    Determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D) of XMT-1660

    17 months

  • Incidence of adverse events (Dose Escalation and Dose Expansion)

    Assess the safety and tolerability of XMT-1660 by determining the number of patients with adverse events from date of first dose to 30 days post last dose

    3 years

  • Objective Response Rate (ORR) (Dose Expansion)

    The percentage of patients with a best overall response of complete or partial response as assessed by the investigator per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1

    approximately 3 years

Secondary Outcomes (10)

  • Objective Response Rate (ORR) (Dose Escalation)

    Up to approximately 3 years

  • Duration of response (DOR) (Dose Escalation and Dose Expansion)

    Up to approximately 3 years

  • Time of maximum observed plasma concentration of XMT-1660 (Tmax) (Dose Expansion)

    3 years

  • Maximum observed plasma concentration of XMT-1660 (Cmax) (Dose Expansion)

    3 years

  • Area under the concentration-time curve of XMT-1660 (AUC) (Dose Expansion)

    3 years

  • +5 more secondary outcomes

Study Arms (1)

XMT-1660

EXPERIMENTAL

Single arm XMT-1660 alone (monotherapy)

Drug: XMT-1660

Interventions

XMT-1660 will be administered through a vein in your arm or port catheter (intravenously)

XMT-1660

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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 non-target lesion as defined by RECIST version 1.1. Participants in Backfill Cohorts and EXP 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:
  • All participants with TNBC
  • Participants with a history of brain metastases or with neurologic symptoms or signs suspicious for brain metastases.

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (26)

Mayo Clinic Comprehensive Cancer Center

Phoenix, Arizona, 85054, United States

RECRUITING

UC Irvine Health-Chao Family Comprehensive Cancer Center

Orange, California, 92868, United States

RECRUITING

UCSF Helen Diller Family Comprehensive Cancer Center

San Francisco, California, 94158, United States

RECRUITING

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

Santa Monica, California, 90404, United States

RECRUITING

Mayo Clinic - Jacksonville

Jacksonville, Florida, 32224, United States

RECRUITING

Florida Cancer Specialists

Sarasota, Florida, 34232, United States

RECRUITING

Moffitt Cancer Center

Tampa, Florida, 33612, United States

RECRUITING

Winship Cancer Institute, Emory University

Atlanta, Georgia, 30322, United States

RECRUITING

Northwestern University

Chicago, Illinois, 60611, United States

RECRUITING

Beth Israel Deaconess Medical Center

Boston, Massachusetts, 02215, United States

RECRUITING

Dana-Farber Cancer Institute

Boston, Massachusetts, 02215, United States

RECRUITING

Henry Ford Health Hospital

Detroit, Michigan, 48202, United States

RECRUITING

Mayo Clinic - Rochester

Rochester, Minnesota, 55905, United States

RECRUITING

Comprehensive Cancer Centers of Nevada

Las Vegas, Nevada, 89169, United States

RECRUITING

New York University Langone Health

New York, New York, 10016, United States

RECRUITING

ICHAN School of Medicine at Mount Sinai

New York, New York, 10029, United States

NOT YET RECRUITING

Memorial Sloan Kettering Cancer Center

New York, New York, 10065, United States

RECRUITING

Stephenson Cancer Center Oklahoma University Health

Oklahoma City, Oklahoma, 73104, United States

RECRUITING

Avera Cancer Institute

Sioux Falls, South Dakota, 57105, United States

RECRUITING

Sarah Cannon Research Institute (SCRI)

Nashville, Tennessee, 37203, United States

RECRUITING

Texas Oncology, P.A.

Dallas, Texas, 75251, United States

RECRUITING

MD Anderson

Houston, Texas, 77030, United States

RECRUITING

Huntsman Cancer Institute

Salt Lake City, Utah, 84112, United States

RECRUITING

NEXT Oncology Virginia

Fairfax, Virginia, 22031, United States

RECRUITING

Fred Hutchinson Cancer Center

Seattle, Washington, 09109, United States

RECRUITING

Summit Cancer Centers

Spokane, Washington, 99208, United States

RECRUITING

Related Publications (1)

  • Toader D, Fessler SP, Collins SD, Conlon PR, Bollu R, Catcott KC, Chin CN, Dirksen A, Du B, Duvall JR, Higgins S, Kozytska MV, Bellovoda K, Faircloth C, Lee D, Li F, Qin L, Routhier C, Shaw P, Stevenson CA, Wang J, Wongthida P, Ter-Ovanesyan E, Ditty E, Bradley SP, Xu L, Yin M, Yurkovetskiy AV, Mosher R, Damelin M, Lowinger TB. Discovery and Preclinical Characterization of XMT-1660, an Optimized B7-H4-Targeted Antibody-Drug Conjugate for the Treatment of Cancer. Mol Cancer Ther. 2023 Sep 5;22(9):999-1012. doi: 10.1158/1535-7163.MCT-22-0786.

MeSH Terms

Conditions

Triple Negative Breast NeoplasmsBreast NeoplasmsEndometrial NeoplasmsOvarian NeoplasmsFallopian Tube NeoplasmsCarcinoma, Adenoid Cystic

Condition Hierarchy (Ancestors)

Neoplasms by SiteNeoplasmsBreast DiseasesSkin DiseasesSkin and Connective Tissue DiseasesUterine NeoplasmsGenital Neoplasms, FemaleUrogenital NeoplasmsUterine DiseasesGenital Diseases, FemaleFemale Urogenital DiseasesFemale Urogenital Diseases and Pregnancy ComplicationsUrogenital DiseasesGenital DiseasesEndocrine Gland NeoplasmsOvarian DiseasesAdnexal DiseasesEndocrine System DiseasesGonadal DisordersFallopian Tube DiseasesAdenocarcinomaCarcinomaNeoplasms, Glandular and EpithelialNeoplasms by Histologic Type

Study Officials

  • Robert Burger, MD

    Mersana Therapeutics

    STUDY DIRECTOR

Central Study Contacts

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NA
Masking
NONE
Purpose
TREATMENT
Intervention Model
SINGLE GROUP
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 2, 2022

First Posted

May 17, 2022

Study Start

August 15, 2022

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

May 1, 2027

Last Updated

April 14, 2026

Record last verified: 2025-10

Data Sharing

IPD Sharing
Will not share

Locations