NCT04896697

Vilastobart (XTX101) Monotherapy and Vilastobart and Atezolizumab Combination Therapy in Advanced Solid Tumors

A First-in-Human, Multicenter, Phase 1/2, Open-Label Study of Vilastobart (XTX101) Monotherapy and Vilastobart (XTX101) and Atezolizumab Combination Therapy in Patients With Advanced Solid Tumors

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 136 (estimated)
• Sponsor: Xilio Development, Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This is a first-in-human, Phase 1/2, multicenter, open-label study designed to evaluate the safety and tolerability of vilastobart (XTX101) as monotherapy and vilastobart (XTX101) and atezolizumab combination therapy in patients with advanced solid tumors.

Detailed description

This is a first-in-human, Phase 1/2, multicenter, open-label study designed to evaluate the safety and tolerability of vilastobart (XTX101), a tumor-selective anti-CTLA-4 antibody, as monotherapy and vilastobart (XTX101) and atezolizumab combination therapy in patients with advanced solid tumors. Part 1A will examine vilastobart (XTX101) monotherapy in an accelerated and standard 3+3 dose escalation design. Based on the results of Part 1A, patients with select advanced solid tumors will be enrolled in Part 1B, which will evaluate vilastobart (XTX101) monotherapy in relation to specific PD biomarkers. Part 1C will examine vilastobart (XTX101) in combination with atezolizumab in a standard 3+3 dose escalation/dose de-escalation design. Part 1C may include a dose expansion cohort to further evaluate the safety, PK, and PD of dose levels that were previously cleared. Phase 2 will examine vilastobart (XTX101) in combination with atezolizumab in patients with metastatic microsatellite stable colorectal cancer (MSS CRC) at the RP2D(s) defined in Part 1C.

Conditions

• Advanced Solid Tumor

Interventions

Type	Name	Description
DRUG	vilastobart (XTX101)	vilastobart (XTX101) monotherapy
DRUG	Atezolizumab	1200 mg administered every 3 weeks in combination with vilastobart (XTX101)
DRUG	vilastobart (XTX101)	In combination with Atezolizumab

Timeline

• Start date: 2021-09-13
• Primary completion: 2026-03-30
• Completion: 2026-03-30
• First posted: 2021-05-21
• Last updated: 2025-05-29

Locations

19 sites across 1 country: United States

Regulatory

• FDA-regulated drug study