Comparative ¹⁸F-FDG and ⁶⁸Ga-MY6349 PET/CT Imaging for Assessing TROP2 ADC Therapeutic Efficacy in EGFR-TKI Resistant Advanced NSCLC

Summary

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.

Conditions

• NSCLC
• EGFR Activating Mutation
• EGFR-TKI-resistant Non-Small Cell Lung Cancer
• Trop2
• PET/CT Imaging

Interventions

DIAGNOSTIC_TEST

receive treatment with TROP2-targeted ADC and targeted molecular PET/CT imaging using ⁶⁸Ga-MY6349 injection

All enrolled subjects shall receive treatment with TROP2-targeted ADC and undergo targeted molecular PET/CT imaging with ⁶⁸Ga-MY6349 injection at prespecified time points.

Sponsors & Collaborators

• Guangzhou Institute of Respiratory Disease

  collaborator OTHER

• Zhou Chengzhi

  lead OTHER

Study Design

Allocation

NA

Purpose

DIAGNOSTIC

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-07-31

Primary Completion

2028-07-31

Completion

2028-07-31