EGFR-TKI-resistant Non-Small Cell Lung Cancer

The goal of this Phase 1 clinical trial is to learn whether all-trans retinoic acid (ATRA) combined with tislelizumab is safe and tolerable in adults with EGFR-mutant non-small cell lung cancer (NSCLC). The study is for people whose cancer has worsened after treatment with a third-generation EGFR tyrosine kinase inhibitor and at least one standard systemic treatment, or who cannot tolerate or are not suitable for currently available standard treatments. The main questions this study aims to answer are: * What side effects and dose-limiting toxicities occur with the combination of ATRA and tislelizumab? * What is the highest dose of ATRA that can be given safely with tislelizumab, and what dose should be recommended for future studies? Researchers will also look for early signs that the combination can shrink or control the cancer and will assess how long participants live without their cancer getting worse and how long they live overall. Tumor tissue and blood samples will be studied to explore changes in the cancer and the immune system and to identify possible markers associated with treatment response or side effects. All participants will receive ATRA and tislelizumab; there is no comparison or placebo group. Participants will: * Take ATRA by mouth twice daily, beginning 7 days before the first dose of tislelizumab. The ATRA dose will be assigned according to the dose level being studied. * Receive tislelizumab by intravenous infusion once every 3 weeks. * Undergo regular safety assessments, including physical examinations, blood tests, vital-sign measurements, and monitoring for side effects. * Undergo imaging examinations approximately every 6 weeks during the first year to assess the cancer. * Provide tumor tissue and blood samples for biomarker research. * Attend an end-of-treatment visit, safety follow-up visits, and survival follow-up approximately every 3 months after treatment ends.

The primary objective is to evaluate the correlation between ⁶⁸Ga-MY6349 PET/CT-derived metrics reflecting tumoral TROP2 expression activity (including SUVmax, SUVmean, MTV, TLG, etc.) and progression-free survival (PFS) assessed per RECIST v1.1. This study plans to enroll 100 EGFR-mutant patients with advanced non-small cell lung cancer (NSCLC) who have developed resistance following first-line therapy with third-generation EGFR-TKIs. Screening assessments will be completed within 28 days after patients sign the informed consent form. Eligible subjects will undergo a baseline ⁶⁸Ga-MY6349 PET/CT scan prior to study drug administration, with imaging coverage from mid-thighs to the vertex of the skull. All subjects will receive a ¹⁸F-FDG PET/CT scan within 14 days after the ⁶⁸Ga-MY6349 PET/CT. For patients who have undergone ¹⁸F-FDG PET/CT within 14 days before the ⁶⁸Ga-MY6349 scan, the existing imaging data can be used for diagnostic performance evaluation, and repeat ¹⁸F-FDG PET/CT is not required. Subsequently, subjects will receive monotherapy with sacituzumab govitecan at a dose of 5 mg/kg via intravenous infusion (IV) on Day 1 of each cycle, administered every 2 weeks (Q2W). Treatment will continue until investigator-confirmed radiological disease progression, intolerable adverse toxicity, voluntary treatment discontinuation by the subject, or any other protocol-specified treatment discontinuation criterion, whichever occurs first. At 3 months after initiation of sacituzumab govitecan treatment, subjects will repeat the ⁶⁸Ga-MY6349 PET/CT scan (coverage: mid-thighs to vertex), followed by a ¹⁸F-FDG PET/CT examination within 14 days thereafter. Eligible subjects will receive regular tumor assessments in accordance with RECIST v1.1. Within 48 weeks after the first dose, imaging-based tumor assessments will be performed every 6 weeks (±7 days). At Week 12 (±1 week), paired ⁶⁸Ga-MY6349 and ¹⁸F-FDG PET/CT scans will be conducted without routine diagnostic CT. After Week 48, tumor assessments will be scheduled every 12 weeks (±7 days) until radiological disease progression, initiation of subsequent anti-tumor therapy, withdrawal of informed consent, loss to follow-up, death, or study termination by the sponsor, whichever comes first. Imaging assessments will follow the predetermined schedule regardless of dose delays or dose modifications. After the first documented complete response (CR) or partial response (PR), response confirmation imaging must be conducted no less than 4 weeks (28 days) later. For subjects discontinuing treatment for reasons other than radiological progression, death or loss to follow-up, if more than 4 weeks have passed since the last imaging evaluation, repeat imaging will be performed at the End-of-Treatment (EOT) visit. Subsequent imaging assessments will be conducted per schedule to the greatest extent feasible until radiological disease progression, initiation of new anti-tumor therapy, consent withdrawal, loss to follow-up, death, or sponsor-initiated study termination, whichever occurs earliest. All ⁶⁸Ga-MY6349 PET/CT images will be blindly and independently reviewed by two experienced nuclear medicine physicians who are not involved in this clinical trial (without access to any clinical data) to identify positive NSCLC lesions, as well as lesion location and count. In case of disagreement between the two independent readers regarding the presence of positive lesions, a blinded arbitration review by a senior nuclear medicine expert will be activated, and the arbitrator's reading results will serve as the final conclusion. All ¹⁸F-FDG PET/CT images will undergo single blinded independent review by one nuclear medicine physician. Upon completion of treatment, all subjects will complete safety follow-up regardless of whether they receive subsequent anti-tumor therapy. Telephone-based survival follow-up visits will be conducted every 3 months (±14 days) after the last dose of study treatment to collect survival status and information on subsequent anti-tumor treatments, until subject withdrawal, loss to follow-up, death, or study closure, whichever occurs first.

This is a single-arm study designed to evaluate the safety and efficacy of TILs combined with third-generation EGFR-TKIs therapy for patients with EGFR-mutant NSCLC resistant to TKI.