for people ages 18 years and up (full criteria)
at Orange, California and other locations
study started
estimated completion
Principal Investigator
by Ritesh Parajuli



A Study of XMT-1660 in Solid Tumors

Official Title

A Phase 1, First-in-human, Dose Escalation and Expansion, Multicenter Study of XMT-1660 in Participants With Solid Tumors


This first-in-human (FIH) study will test the safety and side effects of a drug called XMT-1660. A side effect is anything a drug does to the body besides treating the disease.

Participants in the study will have cancer that has come back after a period of time during which the cancer could not be detected (recurrent), spread in the body near where it started (advanced) or spread through the body (metastatic).

The study will have two parts. The first part called Dose Escalation will find out how much XMT-1660 should be given to participants. The second part called Dose Expansion will use the dose found in the first part to find out how safe XMT-1660 is and if it works to treat solid tumor cancers.


Triple Negative Breast Cancer, Breast Cancer, Endometrial Cancer, Ovarian Cancer, Fallopian Tube Cancer, Primary Peritoneal Cavity Cancer, Breast Neoplasms, Endometrial Neoplasms, Triple Negative Breast Neoplasms, Fallopian Tube Neoplasms, XMT-1660


You can join if…

Open to people ages 18 years and up

  • Participant has proven recurrent or advanced solid tumor and has disease progression after treatment with available anti-cancer therapies known to confer benefit or is intolerant to treatment.
  • Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
  • Participant must have at least one measurable lesion(s) as defined by RECIST version 1.1.
  • Participant must be willing to undergo a minimally invasive tumor biopsy to obtain tumor tissue for local testing, if medically feasible, prior to C1D1. If the investigator feels a biopsy is not medically feasible, an exemption request must be submitted to the study Medical Monitor for approval.

You CAN'T join if...

  • Prior treatment with an Antibody Drug Conjugate (ADC) containing an auristatin or maytansinoid 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 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.
  • Participant has current severe, uncontrolled systemic disease (e.g., clinically significant cardiovascular, pulmonary, or metabolic disease) or intercurrent illness that could interfere with per-protocol evaluations. Further, participants are excluded with the following characteristics:
  • Participant has untreated CNS metastases (including new and progressive brain metastases), history of leptomeningeal metastasis or carcinomatous meningitis.
    1. Participants are eligible if CNS metastases are adequately treated, and participants are neurologically stable for at least 2 weeks prior to enrollment.
    2. In addition, participants must be either off corticosteroids, or on a stable/decreasing dose of ≤ 10 mg daily prednisone (or equivalent). Anticonvulsants are allowed except for those drugs associated with liver toxicity


  • UC Irvine Health-Chao Family Comprehensive Cancer Center accepting new patients
    Orange California 92868 United States
  • Summit Cancer Centers accepting new patients
    Spokane Washington 99208 United States

Lead Scientist at UC Irvine

  • Ritesh Parajuli
    Associate Clinical Professor, Medicine, School of Medicine. Authored (or co-authored) 18 research publications


accepting new patients
Start Date
Completion Date
Mersana Therapeutics
Phase 1 research study
Study Type
Expecting 166 study participants
Last Updated