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

Phase 1
Recruiting
Conditions
Advanced Solid Tumor
Interventions
Drug: vilastobart (XTX101)
Registration Number
NCT04896697
Lead Sponsor
Xilio Development, Inc.
Brief 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.

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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
136
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 cytologically confirmed solid tumor malignancy for which anti-PD-1 or anti-PD-L1 treatment is approved and has progressed on or after prior anti-PD-1 or anti-PD-L1 therapy.
    • Patients with metastatic castrate-resistant prostate cancer if they have progressed on at least 2 lines of systemic therapy
    • Patients with extensive stage small cell lung cancer (SCLC) after at least 1 line of prior therapy
    • Patients with microsatellite stable colorectal cancer after at least 2 lines of prior therapy
  • Phase 2: Patients with histologically confirmed metastatic MSS CRC are eligible to enroll in Phase 2 as follows:

    • Patients must have had at least 1 prior chemotherapy regimen for metastatic CRC including all of the following agents: a fluoropyrimidine, irinotecan, oxaliplatin, bevacizumab or biosimilars, an anti epidermal growth factor receptor antibody (cetuximab or panitumumab), and v-raf murine sarcoma viral oncogene homolog B1 inhibitor/BRAF (encorafenib), if applicable
    • Patients with MSI-H/dMMR are excluded
  • ECOG performance status of 0 or 1

  • Adequate organ function

  • Part 1B, Part 1C, and Phase 2 only: measurable disease per iRECIST

Exclusion Criteria
  • Received prior treatment with anti-CTLA-4 therapy
  • Received prior immune-checkpoint therapy and experienced Grade 3 or greater toxicity lasting greater than 6 weeks
  • Received prior systemic anticancer therapy within 4 weeks prior to study treatment
  • Received prior radiotherapy within 2 weeks prior to study treatment
  • Phase 2 only: Received prior anti-PD-1/L1 therapy or any investigational checkpoint inhibitory therapy
  • Has a diagnosis of immunodeficiency
  • Has known malignancy (other than disease under study) that is progressing or has required active treatment within the past 3 years
  • Has an active autoimmune disease that has required systemic treatment in past 2 years, including the use of disease modifying agents, corticosteroids or immunosuppressive drugs
  • Has an active infection requiring systemic intravenous therapy within 4 weeks prior to study treatment, or oral therapy within 2 weeks prior to study treatment
  • Has a history of severe hypersensitivity reaction (≥ Grade 3) to any study intervention and/or any of its excipients
  • Has a known psychiatric or substance abuse disorder that would interfere with the participant's ability to cooperate with the requirements of the study
  • Phase 2 only: symptomatic bowel obstruction

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Part 1A - vilastobart (XTX101) Monotherapy Dose Escalationvilastobart (XTX101)Part 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 Expansionvilastobart (XTX101)Part 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 in Combination with Atezolizumabvilastobart (XTX101)Part 1C will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101).
Phase 2 - vilastobart (XTX101) Dose Expansion in Combination with Atezolizumabvilastobart (XTX101)Phase 2 will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101) at the RP2D(s) in patients with MSS CRC.
Part 1C - vilastobart (XTX101) Dose Escalation in Combination with AtezolizumabAtezolizumabPart 1C will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101).
Phase 2 - vilastobart (XTX101) Dose Expansion in Combination with AtezolizumabAtezolizumabPhase 2 will receive a labeled dose of atezolizumab in combination with vilastobart (XTX101) at the RP2D(s) in patients with MSS CRC.
Primary Outcome Measures
NameTimeMethod
Incidence of changes in clinical laboratory abnormalities in Part 1Up to 24 months
Investigator-assessed objective response rate (ORR) per iRECIST in Phase 2Up to 24 months
Incidence of Dose Limiting Toxicities (DLTs) in Part 1ACycle 1 Day 1 up to just prior to the second dose of study drug at Cycle 2 day 1 (approximately 3 weeks)
Incidence of treatment-emergent adverse events in Part 1Up to 24 months
Incidence of Dose Limiting Toxicities (DLTs) in Part 1CCycle 1 Day 1 up to Cycle 3 Day 1 (approximately 6 weeks)
Secondary Outcome Measures
NameTimeMethod
Investigator-assessed objective response rate (ORR) per iRECIST in Part 1Up to 24 months
Antidrug antibody (ADA) occurrence and titer in serum in Part 1Up to 24 months
Plasma concentrations of vilastobart (XTX101) (total and intact) in Part 1 and Phase 2Up to 24 months
Maximum observed plasma concentration (Cmax) in Part 1 and Phase 2Up to 24 months
Time of maximum observed concentration (Tmax) in Part 1 and Phase 2Up to 24 months
Trough concentrations (Ctrough) in Part 1 and Phase 2Up to 24 months
Area under the curve (AUC) in Part 1 and Phase 2Up to 24 months
Half-life (T1/2) in Part 1 and Phase 2Up to 24 months
Systemic clearance (CL) in Part 1 and Phase 2Up to 24 months
Volume of distribution (Vd) in Part 1 and Phase 2Up to 24 months
Investigator-assessed ORR per RECIST in Phase 2Up to 24 months
Duration of response in Phase 2Up to 24 months

The time from first documented confirmed response to first documented disease progression

Disease control rate in Phase 2Up to 24 months

The percent of patients who achieve complete response per iRECIST (iCR), partial response per iRECIST (iPR), or stable disease per iRECIST (iSD)

Progression-free survival in Phase 2Up to 24 months

The time from first dose to first documented disease progression or death

Overall survival in Phase 2Up to 24 months

The time from first dose to death due to any cause

Incidence of treatment-emergent AEs in Phase 2Up to 24 months
Incidence of changes in clinical laboratory abnormalities in Phase 2Up to 24 months

Trial Locations

Locations (16)

Mayo Clinic Hospital

🇺🇸

Rochester, Minnesota, United States

City of Hope

🇺🇸

Duarte, California, United States

City of Hope-Lennar

🇺🇸

Irvine, California, United States

USC/Norris Comprehensive Cancer Center

🇺🇸

Los Angeles, California, United States

City of Hope-Upland

🇺🇸

Upland, California, United States

Duke University Medical Center

🇺🇸

Durham, North Carolina, United States

California Cancer Associates for Research and Excellence, cCARE

🇺🇸

San Marcos, California, United States

UCLA Hematology/Oncology- Santa Monica

🇺🇸

Santa Monica, California, United States

Sarah Cannon Research Institute at Florida Cancer Specialists

🇺🇸

Orlando, Florida, United States

Massachusetts General Hospital

🇺🇸

Boston, Massachusetts, United States

Carolina BioOncology Institute

🇺🇸

Huntersville, North Carolina, United States

University of Pittsburgh Medical Center- Hillman Cancer Center

🇺🇸

Pittsburgh, Pennsylvania, United States

Next Oncology

🇺🇸

Austin, Texas, United States

Mary Crowley Cancer Research

🇺🇸

Dallas, Texas, United States

Tranquil Clinical Research

🇺🇸

Webster, Texas, United States

NEXT Virginia

🇺🇸

Fairfax, Virginia, United States

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