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vilastobart

Phase 1

Advanced Solid Tumor | Small molecule | Oncology |Xilio Therapeutics, Inc.|Last Updated: Jun 16, 2026

Success Probability

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Market & Valuation

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Trial Design

CONTROLLED
Total Trials1
Total Enrollment125

FDA Designations

No designations recorded

Clinical trial landscape

vilastobart · 1 trial · 1 indication

Phase 1 1
NCT04896697Vilastobart (XTX101) Monotherapy and Vilastobart and Atezolizumab Combination Therapy in Advanced Solid TumorsAdvanced Solid Tumor
COMPLETED125 Analytics
PHASE1COMPLETED
Vilastobart (XTX101) Monotherapy and Vilastobart and Atezolizumab Combination Therapy in Advanced Solid Tumors
Advanced Solid TumorUnlock trial analytics

Study Endpoints

Primary Endpoints

Incidence of Dose Limiting Toxicities (DLTs) in Part 1A
Cycle 1 Day 1 up to just prior to the second dose of study drug at Cycle 2 day 1 (approximately 3 weeks)
Incidence of Dose Limiting Toxicities (DLTs) in Part 1C
Cycle 1 Day 1 up to Cycle 3 Day 1 (approximately 6 weeks)
Incidence of treatment-emergent adverse events in Part 1
Up to 24 months
Incidence of changes in clinical laboratory abnormalities in Part 1
Up to 24 months
Investigator-assessed objective response rate (ORR) per iRECIST in Phase 2
Up to 24 months

Secondary Endpoints

Investigator-assessed objective response rate (ORR) per iRECIST in Part 1
Up to 24 months
Antidrug antibody (ADA) occurrence and titer in serum in Part 1
Up to 24 months
Plasma concentrations of vilastobart (XTX101) (total and intact) in Part 1 and Phase 2
Up to 24 months
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Study Design & Arms

AllocationNON_RANDOMIZED
MaskingNONE
ModelSEQUENTIAL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Part 1A - vilastobart (XTX101) Monotherapy Dose EscalationEXPERIMENTALPart 1A Dose Escalation of vilastobart (XTX101) administered in ascending doses to patients with advanced or metastatic solid tumors to find the recommended phase 2 dose (RP2D).
Part 1B - Pharmacodynamic (PD) Dose ExpansionEXPERIMENTALPart 1B vilastobart (XTX101) at the RP2D will be administered to further examine vilastobart (XTX101) as monotherapy in patients with select advanced solid tumors.
Part 1C - vilastobart (XTX101) Dose Escalation and Dose Expansion in Combination with AtezolizumabEXPERIMENTALPart 1C will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101).
Phase 2 - vilastobart (XTX101) Dose Expansion in Combination with AtezolizumabEXPERIMENTALPhase 2 will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101) at the RP2D(s) in patients with MSS CRC.

Interventions

NameTypeDescription
vilastobart (XTX101)DRUGvilastobart (XTX101) monotherapy
AtezolizumabDRUG1200 mg administered every 3 weeks in combination with vilastobart (XTX101)
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites19

Inclusion Criteria: Disease Criteria - * Part 1A and 1C: Any histologically or cytologically confirmed solid tumor malignancy that is locally advanced or metastatic and has failed standard therapy, or standard therapy is not curative or available; * Part 1B: * Any histologically or cytologicall...

Countries:United States
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Competitive Landscape -Other Solid Tumors 9 trials (matched to "Advanced Solid Tumor")

Recent Changes (Last 90 Days)

MEDIUMJul 17, 2026NCT04896697TRIAL_REMOVED: changed
MEDIUMJul 17, 2026NCT04896697TRIAL_REMOVED: changed
MEDIUMJul 17, 2026NCT04896697TRIAL_REMOVED: changed
HIGHJun 16, 2026NCT04896697Status: ACTIVE_NOT_RECRUITING → COMPLETED
HIGHJun 16, 2026NCT04896697Status: ACTIVE_NOT_RECRUITING → COMPLETED
HIGHJun 16, 2026NCT04896697Status: ACTIVE_NOT_RECRUITING → COMPLETED
MEDIUMMay 26, 2026NCT04896697Status: RECRUITING → ACTIVE_NOT_RECRUITING
LOWMay 24, 2026NCT04896697studyFirstPostDate: changed

Frequently asked questions about vilastobart

What is vilastobart used for?

Vilastobart is an investigational small molecule being studied for the treatment of advanced solid tumors. It is currently in Phase 1 clinical development and has not been approved by regulatory authorities. The drug is being evaluated as a monotherapy and in combination with atezolizumab in patients with advanced solid tumors.

Who makes vilastobart?

Vilastobart is being developed by Xilio Therapeutics, Inc., a biopharmaceutical company traded on the NASDAQ under the ticker symbol XLO. The company is conducting clinical trials to evaluate the safety and efficacy of vilastobart in patients with advanced solid tumors.

What phase is vilastobart in?

Vilastobart is currently in Phase 1 clinical development. It is an investigational drug and has not received FDA approval. The Phase 1 trial has been completed, and the drug is being studied for the treatment of advanced solid tumors.

What clinical trials is vilastobart in?

Vilastobart has been studied in a Phase 1 clinical trial with the identifier NCT04896697. This trial evaluated vilastobart as a monotherapy and in combination with atezolizumab in patients with advanced solid tumors. The trial was conducted in the United States and enrolled 125 participants.

Is vilastobart the same as XTX101?

Yes, vilastobart is also known as XTX101. The clinical trial NCT04896697, which evaluated vilastobart, is titled 'Vilastobart (XTX101) Monotherapy and Vilastobart and Atezolizumab Combination Therapy in Advanced Solid Tumors.' Both names refer to the same investigational drug.