Investigating TAS3351 for advanced non-small cell lung cancer with specific mutations

A Phase 1/2 Study of TAS3351 in Patients With Advanced Non-Small Cell Lung Cancer and EGFR Mutations

Phase1; Phase2 Interventional Taiho Oncology, Inc. · NCT05765734

This study is testing a new oral medication called TAS3351 to see if it can safely help people with advanced lung cancer that has a specific mutation.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment200 (estimated)
Ages18 Years and up
SexAll
SponsorTaiho Oncology, Inc. Industry-sponsored
Locations17 sites (Washington, District of Columbia and 16 other locations)
Trial IDNCT05765734 on ClinicalTrials.gov

What this trial studies

This study is a first-in-human, open-label investigation of TAS3351, focusing on its safety and efficacy in patients with advanced or metastatic non-small cell lung cancer (NSCLC) that has the C797S EGFR mutation. The trial consists of three parts: a dose escalation phase to determine the optimal dosage, a dose expansion phase to evaluate efficacy, and a phase 2 portion to further assess the treatment's effectiveness. Participants will receive TAS3351 orally, and the study aims to provide insights into its therapeutic potential for this specific patient population.

Who should consider this trial

Good fit: Ideal candidates include individuals with locally advanced, non-resectable, or metastatic NSCLC who have the C797S EGFR mutation and meet specific health criteria.

Not a fit: Patients with symptomatic and unstable CNS metastases or those unable to swallow or digest pills may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could offer a new therapeutic option for patients with advanced NSCLC harboring the C797S mutation.

How similar studies have performed: Other studies targeting EGFR mutations in NSCLC have shown promise, but the specific approach of TAS3351 in this context is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Locally advanced, non-resectable or metastatic NSCLC
* Have adequate organ function
* Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale
* Has tumor tissue available to allow for analysis of EGFRmt status

Dose Escalation:

• Has any EGFRmt status

Dose Escalation back-fill part, Dose Expansion and Phase II:

* Has any sensitizing EGFRmt and a confirmed C797S EGFRmt
* Has measurable disease per RECIST v1.1

Exclusion Criteria:

* Participating in medical research not compatible with this study
* Symptomatic and unstable CNS metastases
* Have not recovered from prior cancer treatment
* Have a significant cardiac condition
* Are a pregnant or breastfeeding female
* A serious illness or medical condition
* Unable to swallow or digest pills

Where this trial is running

Washington, District of Columbia and 16 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Non-Small Cell Lung CancerNSCLCEGFR mutationC797S mutationTAS3351
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.