First-In-Human Study of STX-721/PFL-721 in Participants With Locally Advanced or Metastatic Non-Small Cell Lung Cancer Harboring EGFR or HER2 Exon 20 Insertion Mutations

August 31, 2026 updated by: Pierre Fabre Medicament
Study STX-721-101/PFL-721CI101 is an open label, Phase 1/2 study evaluating the safety, tolerability, pharmacokinetic (PK) exposure, and preliminary antitumor activity of STX-721/PFL-721 in participants with non-small cell lung cancer (NSCLC) carrying EGFR or HER2 exon 20 insertion (ex20ins) mutations.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
345

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Toulouse, France, 31059
        • Recruiting
        • Institut Claudius Regaud - PPDS
      • Villejuif, France, 94800
        • Recruiting
        • Gustave Roussy
    • Loire-Atlantique
      • Saint-Herblain, Loire-Atlantique, France, 44115
        • Recruiting
        • EDOG Institut de Cancerologie de l'Ouest - PPDS
  • Germany
      • Berlin, Germany, 12203
        • Recruiting
        • Charité - Universitätsmedizin Berlin (CBF) - Hindenburgdamm 30
      • Dresden, Germany, 01307
        • Recruiting
        • Universitätsklinikum Carl Gustav Carus an der TU Dresden
  • Netherlands
      • Amsterdam, Netherlands, 1066
        • Recruiting
        • Nederlands Kanker Instituut-Antoni van Leeuwenhoek Ziekenhuis
  • South Korea
      • Cheongju-si, South Korea, 28644
        • Recruiting
        • Chungbuk National University Hospital
      • Seongnam-si, South Korea, 13496
        • Recruiting
        • CHA Bundang Medical Center, CHA University
      • Seoul, South Korea, 03080
        • Recruiting
        • Seoul National University Hospital
  • Spain
      • Barcelona, Spain, 8035
        • Recruiting
        • Instituto de Investigacion Oncologica Vall dHebron (VHIO) - EPON
      • Madrid, Spain, 28034
        • Recruiting
        • Hospital Universitario Ramon Y Cajal
      • Seville, Spain, 41013
        • Recruiting
        • Hospital Universitario Virgen del Rocío
    • La Rioja
      • Logroño, La Rioja, Spain, 26006
        • Recruiting
        • START - Rioja Hospital Universitario San Pedro
    • Malaga
      • Málaga, Malaga, Spain, 29010
        • Recruiting
        • Hospital Regional Universitario de Malaga - Hospital General
  • Taiwan
      • Taipei, Taiwan, 10002
        • Recruiting
        • National Taiwan University Hospital
      • Taipei, Taiwan, 11217
        • Recruiting
        • Taipei Veterans General Hospital
  • United States
    • California
      • Duarte, California, United States, 91010
        • Recruiting
        • City of Hope
      • Huntington Beach, California, United States, 92648
        • Recruiting
        • City of Hope
      • Irvine, California, United States, 92618
        • Recruiting
        • City of Hope
    • North Carolina
      • Charlotte, North Carolina, United States, 28204-2990
        • Recruiting
        • Levine Cancer Institute - Charlotte
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19107
        • Recruiting
        • Thomas Jefferson University Research Facility
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • SCRI Oncology Partners - PPDS
    • Texas
      • Houston, Texas, United States, 77030-4009
        • Recruiting
        • University of Texas MD Anderson Cancer Center
    • Utah
      • Salt Lake City, Utah, United States, 84112-5550
        • Recruiting
        • University of Utah - Huntsman Cancer Institute - PPDS
    • Virginia
      • Fairfax, Virginia, United States, 22031-2171
        • Recruiting
        • NEXT Virginia

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Has histologically- or cytologically confirmed diagnosis of NSCLC Stage IIIB/C or IV not eligible for curative intent surgery or chemoradiation
  2. Part 1: Tumor tissue EGFR or HER2 exon 20 insertion mutations confirmed by qualified local laboratories. Parts 2 and 3: EGFR/HER2 exon 20 insertion mutations confirmed by qualified local laboratories
  3. Part 1: Has received all approved therapies for advanced or metastatic NSCLC or is ineligible. Part 2 and Part 3: Has received at least 1, but not more than 2, prior lines of approved treatment for advanced or metastatic NSCLC, 1 of which must be platinum-based chemotherapy unless contraindicated
  4. Has documented tumor progression (based on radiological imaging)
  5. Has new or recent tumor biopsy (collected at screening, if feasible) or archival tumor specimen collected in the past 10 years available for genomic profiling
  6. Has at least one measurable tumor lesion per RECIST v1.1
  7. Is ≥18 years of age at the time of signing the ICF
  8. Has Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1

Key Exclusion Criteria:

  1. Has a tumor that is known to harbor EGFR ex20ins p.H773_V774insH variant, or any EGFR kinase domain activating mutation concurrent with either a T790M and/or C797S resistance mutations
  2. Has history (within ≤2 years before screening) of solid tumor or hematological malignancy that is histologically distinct from NSCLC
  3. Has symptomatic brain or spinal metastases
  4. Has toxicities from previous anticancer therapies that have not resolved to baseline levels or to CTCAE Grade ≤1, except for alopecia and peripheral neuropathy
  5. Has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (e.g., could compromise the participant's well-being) or would prevent, limit, or confound the protocol-specified assessments

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Part 1: Dose Escalation
Drug: STX-721/PFL-721 (Escalated)
STX-721/PFL-721 dose will be escalated per cBLRM-design.
Experimental: Part 2: RP2D Selection
Drug: STX-721/PFL-721 (3 dose levels)
Participants will receive STX-721/PFL-721 at one of three dose levels.
Experimental: Part 3: Dose Expansion
Drug: STX-721/PFL-721 (RP2D)
Participants will receive the RP2D of STX-721/PFL-721.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Part 1 Dose Escalation (MTD): Dose Escalation - Number of participants who experience at least 1 DLT during the first 28 days of treatment
Time Frame: 28 days
28 days
Part 1 Dose Escalation (OBD): Dose Escalation - Number of participants who experience at least 1 DLT during the first 28 days of treatment
Time Frame: 28 days
28 days
Part 2 RP2D Selection: Number of participants with confirmed objective response rate (ORR) defined as the percentage of participants with partial response (PR) or complete response (CR) based on RECIST v1.1 per investigator assessment.
Time Frame: 1 year
1 year
Part 2 RP2D Selection: C(max) of STX-721/PFL-721
Time Frame: 1 year
1 year
Part 2 RP2D Selection: AUC(0-inf) of STX-721/PFL-721
Time Frame: 1 year
1 year
Part 2 RP2D Selection: AUC(0-t) of STX-721/PFL-721
Time Frame: 1 year
1 year
Part 2 RP2D Selection: AUC(0-τ) of STX-721/PFL-721
Time Frame: 1 year
1 year
Part 3 Dose Expansion: Number of participants with confirmed ORR defined as the percentage of participants with PR or CR based on RECIST v1.1 per investigator assessment.
Time Frame: 1 year
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Pierre Fabre Medicament

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 26, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 1, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 18, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 21, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STX-721-101/PFL-721CI101

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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