Tests STX-721/PFL-721 in lung cancer with EGFR or HER2 exon 20 mutations
Tests STX-721/PFL-721 in adults with lung cancer carrying EGFR or HER2 mutations.
Plain-language title generated from the registry record
Registry title: 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
Key facts
- Where
- Amsterdam, NetherlandsSee the site
- Phase
- Phase 1/2
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with advanced or spread non-small cell lung cancer that carries an EGFR or HER2 exon 20 insertion mutation.
- Age
- 18 years or older.
- Sex
- All sexes can join.
- Disease stage
- Non-small cell lung cancer, stage IIIB/C or IV, that cannot be treated with surgery or chemoradiation meant to remove all of the disease. The cancer has grown on scans and has at least one measurable tumor.
- Earlier treatment
- Part 1: has had all approved treatments for advanced or spread disease, or cannot have them. Parts 2 and 3: has had 1 or 2 earlier approved treatments, one of them platinum-based chemotherapy unless it is not safe.
- Biomarker or test result
- An EGFR or HER2 exon 20 insertion mutation in the tumor, confirmed by a qualified local laboratory.
Main reasons for not taking part
- Tumor with the EGFR ex20ins p.H773_V774insH variant, or an EGFR activating mutation together with T790M and/or C797S
- Another solid tumor or blood cancer different from lung cancer within the last 2 years
- Brain or spinal metastases that cause symptoms
- Side effects of earlier cancer treatment not yet back to baseline or Grade 1 or lower (except hair loss and nerve damage in hands and feet)
Read by machine on 9 November 2026.
Where in Netherlands
- Het Nederlands Kanker Instituut-Antoni van Leeuwenhoek Ziekenhuis StichtingAmsterdam, NetherlandsTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Pierre Fabre Medicament
- Trial code
- NCT06043817EU 2023-506759-51-00
- Record updated
- 30 October 2026
- Original description
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.Read full original descriptionShow less
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
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.
Inclusion: Has histologically- or cytologically confirmed diagnosis of NSCLC Stage IIIB/C or IV not eligible for curative intent surgery or chemoradiation; 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; 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; Has documented tumor progression (based on radiological imaging); 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; Has at least one measurable tumor lesion per RECIST v1.1; Is ≥18 years of age at the time of signing the ICF; Has Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
Exclusion: Has toxicities from previous anticancer therapies that have not resolved to baseline levels or to CTCAE Grade ≤1, except for alopecia and peripheral neuropathy; 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; 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; Has history (within ≤2 years before screening) of solid tumor or hematological malignancy that is histologically distinct from NSCLC; Has symptomatic brain or spinal metastases.