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XTX301 for Advanced Solid Tumors

This study is testing a new treatment called XTX301 for people with advanced solid tumors that have either not responded to standard treatments, or for which standard treatments are not available or beneficial. XTX301 is a type of immunotherapy that works by targeting specific pathways in the body (PD-1, PD-L1) to fight cancer. Researchers want to understand how safe XTX301 is, what side effects it might cause, and if it can shrink tumors. You may be able to join if you have certain types of advanced solid tumors. The study will also look at specific markers (biomarkers) in your tumor, such as DMMR, MSI, MSI-H, PD-1, and PD-L1, to see how they relate to the treatment's effects. The study plans to enroll 358 participants.

Study design
This is a Phase 1/2, open-label study, meaning both you and your doctors will know you are receiving XTX301. It will involve approximately 358 participants and is designed to first find a safe dose and then see how well it works.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Your safety will be monitored for up to 24 months, and tumor responses will be assessed for up to 24 months.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT05684965

XTX301 in Patients With Advanced Solid Tumors

Recruiting
PHASE1Ages 18+InterventionalTreatment
Xilio Development, Inc.
~358 participants
Updated 2026-06-23 on ClinicalTrials.gov
What's tested:XTX301

At a glance

Recruiting sites
10 of 12 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Incidence of Dose Limiting Toxicities (DLTs) (Part 1A only)
Measured over From the first dose of the study drug at Cycle 1 Day 1 up to next applicable cycle visit (Cycle 2 Day 1 or Cycle 3 Day 1). Approximately 21 to 42 days. Each cycle is 21 days.
+3 more outcomes measured

Conditions

Advanced Solid Tumor

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NCT05684965

Where you'd take part

This study runs at 12 sites. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.

  • Hackensack University Medical Center

    Hackensack, New Jerseystudy coordinator listed

    Recruiting

  • HealthPartners Frauenshuh Cancer center

    Saint Louis Park, Minnesotastudy coordinator listed

    Recruiting

  • Medical College of Wisconsin

    Milwaukee, Wisconsinstudy coordinator listed

    Recruiting

  • The Gabrail Pharmacology Phase 1 Research Center

    Canton, Ohiostudy coordinator listed

    Recruiting

  • The Ohio State University Wexner Medical Center

    Columbus, Ohiostudy coordinator listed

    Recruiting

  • University Hospital Cleveland Medical Center

    Cleveland, Ohiostudy coordinator listed

    Recruiting

  • University of California, Davis Comprehensive Cancer Center

    Sacramento, Californiastudy coordinator listed

    Recruiting

  • University of Pittsburgh Medical Center-Hillman Cancer Center

    Pittsburgh, Pennsylvaniastudy coordinator listed

    Recruiting

Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.

Who to contact

Xilio Medical Affairs
[email protected]
(857) 524-2466
Email the study team

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Eligibility criteria

Inclusion

ECOG performance status of 0-2 for Phase 1
ECOG performance status of 0 or 1 for Phase 2
Adequate organ function
Tumor tissue samples: Part 1B: patients must have lesions amenable to biopsy and be willing and able to provide fresh tumor biopsies before and after initiation of treatment
Patients with recent major surgery must have adequately recovered with no ongoing complications from the surgery before receiving study drug

Exclusion

Prior treatment with IL-12 therapy (any form, e.g. recombinant human, prodrug, intratumoral, etc.)
Known liver metastasis based on imaging
Possible area of ongoing necrosis (non-disease-related), such as active ulcer, nonhealing wound, or intercurrent bone fracture
Active primary central nervous system (CNS) malignancy, CNS metastases, and/or carcinomatous meningitis
Active autoimmune disease
History of Grade ≥ 3 immune-related adverse events associated with prior immunotherapy unless these were adequately resolved with therapy within 14 days
A diagnosis of immunodeficiency; receiving chronic systemic therapy exceeding prednisone 10 mg daily or equivalent or any other form of immunosuppressive therapy within 7 days before the first dose of study drug
Active hepatitis B or active hepatitis C infection
Prior treatment with gene therapy, organ transplant, or hematopoietic stem-cell transplant
Known malignancy (other than disease under study) that is progressing or has required active treatment within the past 3 years

What this trial measures

  • Incidence of Dose Limiting Toxicities (DLTs) (Part 1A only)From the first dose of the study drug at Cycle 1 Day 1 up to next applicable cycle visit (Cycle 2 Day 1 or Cycle 3 Day 1). Approximately 21 to 42 days. Each cycle is 21 days.
  • Incidence of treatment-emergent adverse events (TEAEs) and changes in clinical laboratory valuesUp to 24 months
  • Investigator-assessed objective response rate (ORR) per RECIST 1.1 (for all Phase 2 disease specific cohorts except CRPC/APMR-PC)up to 24 months
  • PSA50 response rate and Investigator-assessed ORR per RECIST 1.1 by CT/MRI for patients with measurable disease (for Phase 2 CRPC/APMR-PC cohort only)up to 24 months