Study to Evaluate Safety and Antitumor Activity of Lete-Cel (GSK3377794) in HLA-A2+ Participants With NY-ESO-1 Positive Previously Untreated Advanced (Metastatic or Unresectable) Synovial Sarcoma and Myxoid/Round Cell Liposarcoma

Evaluation of Safety and Antitumor Activity of Lete-Cel (GSK3377794) in HLA-A2+ Participants With NY-ESO-1 Positive Previously Untreated Advanced (Metastatic or Unresectable) Synovial Sarcoma and Myxoid/Round Cell Liposarcoma

This trial will evaluate safety and efficacy of human engineered T-cell therapies, in participants with advanced tumors. This trial is a sub study of the Master study NCT03967223.

Study Overview

• Status: Active, not recruiting
• Conditions: Neoplasms
• Intervention / Treatment: Drug: Fludarabine; Drug: Cyclophosphamide; Drug: Letetresgene autoleucel

• Study Type: Interventional
• Enrollment (Actual): 7
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Toronto, Canada, M5G 2M9
    • Princess Margaret Cancer Centre
  • Quebec
    • Montreal, Quebec, Canada, H1T 2M4
      • CIUSSS de L'Est-De-Lile-De-Montreal
• France
  • Lyon, France, 69373
    • Centre Leon Berard
  • Pessac, France, 33604
    • CHU de Bordeaux GH Sud Hôpital Haut Lévêque
• Italy
  • Milan, Italy, 20133
    • Fondazione IRCCS Instituto Nazionale Dei Tumori
  • Romano di Lombardia, Italy, 20089
    • Ircss Istituto Clinico Humanitas
• Netherlands
  • Amsterdam, Netherlands, 1066 CX
    • The Netherlands Cancer Institute
• Spain
  • Barcelona, Spain, 08025
    • Hospital Santa Creu Y Sant Pau
  • Hospitalet de Llobregat, Barcelona, Spain, 08907
    • Ico Duran y Reynals l'Hospitalet de Llobrega
  • Madrid, Spain, 28040
    • Hospital Universitario Fundacion Jimenez Diaz
  • Seville, Spain, 41013
    • Hospital Virgen Del Rocio
• United Kingdom
  • London, United Kingdom, SW3 6JJ
    • Royal Marsden Hospital
  • London, United Kingdom, WC1E 6AG
    • University College Hospital-London
  • Manchester, United Kingdom, M20 4BX
    • Christie Hospital NHS Foundation Trust
• United States
  • California
    • Duarte, California, United States, 91010
      • City of Hope National Medical Center
    • Stanford, California, United States, 94305
      • Stanford Hospital and Clinics
  • Colorado
    • Denver, Colorado, United States, 80218
      • Sarah Cannon Research Institute
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic Jacksonville
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University of Chicago
  • Iowa
    • Iowa City, Iowa, United States, 52242-1009
      • University of Iowa College of Medicine
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
    • Boston, Massachusetts, United States, 02114
      • Dana Farber Cancer Institute
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan Medical Center
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • Minnesota Oncology Hematology
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic Rochester
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Washington University
  • New York
    • New York, New York, United States, 10065
      • Memorial Sloan Kettering Cancer Center
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center
  • Ohio
    • Columbus, Ohio, United States, 43210
      • Ohio State University-Columbus
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health and Science University
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15232
      • University of Pittsburgh, Hillman Cancer Centre
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Tennessee Oncology
  • Texas
    • Dallas, Texas, United States, 75390-9063
      • University of Texas Southwestern Medical Center
    • Dallas, Texas, United States, 75390-8565
      • University of Texas Southwestern Medical Center
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • University of Utah
  • Virginia
    • Richmond, Virginia, United States, 23298
      • Virginia Commonwealth University
  • Washington
    • Seattle, Washington, United States, 98109-1024
      • Fred Hutchinson Cancer Research Center
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Froedtert Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participant must be greater than or equal to 10 years of age on the day of signing informed consent.
• Participant scheduled to receive clinical drug product supply must also weigh ≥40 kg
• Participant must be positive for HLA-A*02:01, HLA-A*02:05, and/or HLA-A*02:06 alleles by a designated central laboratory
• Participant's tumor is positive for NY-ESO-1 expression by a designated central laboratory.
• Participant has a diagnosis of synovial sarcoma (SS) or myxoid/round cell liposarcoma (MRCLS)
• Performance status: dependent on age - Lansky > 60, Karnofsky > 60, Eastern
• Cooperative Oncology Group 0-1.
• Participant must have adequate organ function and blood cell counts, within 7 days prior to leukapheresis.
• At time of treatment, participant has measurable disease according to RECIST v1.1.
• Male or female. Contraception requirements will apply at the time of leukapheresis and treatment.
• Consultation for prior history per protocol specifications.

Exclusion Criteria:

• Central nervous system metastases.
• Any other prior malignancy that is not in complete remission.
• Clinically significant systemic illness (.(Serious active infections or significant cardiac, pulmonary, hepatic or other organ dysfunction, that in the judgment of the Investigator would compromise the participant's ability to tolerate protocol therapy or significantly increase the risk of complications)
• Prior or active demyelinating disease.
• History of chronic or recurrent (within the last year prior to leukapheresis) severe autoimmune or immune mediated disease (e.g. Crohn's disease, systemic lupus) requiring steroids or other immunosuppressive treatments.
• Previous treatment with genetically engineered NY-ESO-1-specific T cells.
• Previous NY-ESO-1 vaccine or NY-ESO-1 targeting antibody.
• Prior gene therapy using an integrating vector.
• Previous allogeneic hematopoietic stem cell transplant.
• Washout periods for prior radiotherapy and systemic chemotherapy must be followed.
• Participant had major surgery in less than or equal to 28 days of first dose of study intervention.
• Prior radiation exceeds protocol specified limits.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Letetresgene autoleucel	Drug: Fludarabine; Fludarabine will be used as a lymphodepleting chemotherapy.; Drug: Cyclophosphamide; Cyclophosphamide will be used as a lymphodepleting chemotherapy.; Drug: Letetresgene autoleucel; Letetresgene autoleucel will be administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Response Rate (ORR)	ORR is defined as the percentage of participants with a confirmed complete response (CR) or confirmed partial response (PR) via investigator assessment per Response Evaluation Criteria in Solid Tumors Criteria (RECIST) version 1.1 relative to the total number of participants in the analysis population. CR is defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<)10 millimeters (mm). PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the baseline sum of the diameters (e.g., percent change from baseline). 95% CI is based on Clopper-Pearson exact confidence interval.	Up to approximately 36 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Response (TTR)	Time to response was defined as the interval of time between the date of T-cell infusion and the first documented evidence of the confirmed response (PR or CR), in the subset of participants with a confirmed PR or CR as their best confirmed overall response. CR is defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<)10 millimeters (mm). PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the baseline sum of the diameters (e.g., percent change from baseline).	Up to approximately 54 months
Duration of Response (DOR)	Duration of response was defined as the interval between the initial date of confirmed response (PR/CR) and the date of progressive disease as assessed by local investigators, or death among participants with a confirmed response per RECIST 1.1. CR is defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<)10 millimeters (mm). PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the baseline sum of the diameters (e.g., percent change from baseline).	Up to approximately 54 months
Disease Control Rate (DCR)	DCR is defined as the percentage of participants with a confirmed CR, PR, or stable disease (SD) with a minimal 12 weeks (84 days ± 7 day window) duration relative to the total number of participants within the analysis population at the time of primary analysis as determined by local investigators per RECIST v1.1. CR is defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<)10 millimeters (mm). PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the baseline sum of the diameters (e.g., percent change from baseline). SD is defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease. The disease progression (PD) is defined as the date of radiological disease progression based on imaging data per RECIST v1.1. 95% CI is based on Clopper-Pearson exact confidence interval.	Up to approximately 36 months
Progression Free Survival (PFS)	PFS is defined as the interval of time between from the date of T-cell infusion to the earliest date of radiological progression of disease (PD) as assessed by local investigator per RECIST v1.1, or death due to any cause. The PD is defined as the date of radiological disease progression based on imaging data per RECIST v1.1.	Up to approximately 54 months
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (TESAEs)	An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect, other situations which involve medical or scientific judgment or is associated with liver injury and impaired liver function.	Up to approximately 54 months
Number of Participants With AEs of Special Interest (AESIs)	An AESI may be of scientific and medical concern related to the treatment, monitored, and rapidly communicated by investigator to sponsor. AESIs included cytokine release syndrome (CRS), hematopoietic cytopenias (including pancytopenia and aplastic anemia), graft vs host disease (GVHD), ICANS, Guillain-Barre syndrome, treatment-related inflammatory response at tumor site(s), and neutropenia Grade 4 lasting ≥28 days.	Up to approximately 54 months
Number of Participants With TEAEs and TESAEs by Severity	An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect, other situations which involve medical or scientific judgment or is associated with liver injury and impaired liver function. AEs and SAEs were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 5.0. Grade 1- Mild; Grade 2- Moderate; Grade 3- Severe or medically significant but not immediately life-threatening; Grade 4- Life-threatening consequences; Grade 5- Death related to AE.	Up to approximately 54 months
Number of Participants With AESIs by Severity	An AESI may be of scientific and medical concern related to the treatment, monitored, and rapidly communicated by investigator to sponsor. AESIs included cytokine release syndrome (CRS), hematopoietic cytopenias (including pancytopenia and aplastic anemia), graft vs host disease (GVHD), ICANS, Guillain-Barre syndrome, treatment-related inflammatory response at tumor site(s), and neutropenia Grade 4 lasting ≥28 days.	Up to approximately 54 months
Percentage of Participants With Replication Competent Lentivirus (RCL) Positive	RCL was monitored using a polymerase chain reaction (PCR)-based assay that detects and measures copies of the gene coding for the vector's envelope protein, namely vesicular stomatitis virus G protein (VSV-G).	Up to approximately 54 months
Instances of Insertional Oncogenesis (IO)	Instances of Insertional Oncogenesis (IO) was summarized descriptively.	Up to approximately 54 months
Maximum Transgene Expansion (Cmax)	Cmax was defined as maximum observed persistence, determined directly from the persistence-time data. Blood samples were collected for PK analysis.	Day 1 to Day 14
Time to Cmax (Tmax)	Tmax was defined as time to reach Cmax, determined directly from the persistence-time data. Blood samples were collected for PK analysis.	Day 1 to Day 14
Area Under the Time Curve From Zero to Time 28 Days (AUC[0-28])	Area under the persistence-time curve from time zero to Day 28. Blood samples were collected for PK analysis.	Up to 28 days

Collaborators and Investigators

• Sponsor: USWM, LLC (dba US WorldMeds)
• Investigators: Study Director: GSK Clinical Trials, GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Actual): December 31, 2019
• Primary Completion (Actual): October 12, 2022
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: August 7, 2023
• First Submitted That Met QC Criteria: August 7, 2023
• First Posted (Actual): August 15, 2023

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Adoptive T-cell therapy; GSK3377794; Letetresgene autoleucel; Lete-cel
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Sarcoma; Neoplasms, Connective and Soft Tissue; Neoplasms, Connective Tissue; Neoplasms, Adipose Tissue; Neoplasms; Organic Chemicals; Hydrocarbons; Phosphoramide Mustards; Nitrogen Mustard Compounds; Mustard Compounds; Hydrocarbons, Halogenated; Phosphoramides; Organophosphorus Compounds; Cyclophosphamide; fludarabine
• Other Study ID Numbers: 208467 Substudy 1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Qualified researchers may request access to anonymized individual patient-level data (IPD) and related study documents of the eligible studies via the Data Sharing Portal. Details on GSK's data sharing criteria can be found at: https://www.gsk.com/en-gb/innovation/trials/data-transparency/
• IPD Sharing Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or terminated asset(s) across all indications.
• IPD Sharing Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension may be granted, when justified, for up to 6 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No