A Phase 1b/2a clinical study of Legubicin in pretreated non-small cell lung cancer (NSCLC) has been accepted for presentation at the 2026 World Conference on Lung Cancer (WCLC 2026), taking place in Seoul, South Korea. The study is scheduled for the Poster Presentation session and has also been selected for the Poster Tour in the "Metastatic NSCLC – Antibody-Drug Conjugate and Cytotoxic Therapy" session, where the findings will be presented and discussed with attendees onsite.

Organized by the International Association for the Study of Lung Cancer (IASLC), WCLC is one of the most important international scientific meetings in lung cancer and thoracic oncology, bringing together clinicians, researchers, and industry representatives from around the world to share the latest advances in lung cancer and other thoracic malignancies.

Tumor Microenvironment-Selective Activation to Expand the Therapeutic Potential of a Classic Anthracycline

Doxorubicin (DOX) is a classic anthracycline with broad and potent antitumor activity, but its clinical use is limited by cumulative cardiotoxicity and hematologic toxicity, particularly with prolonged treatment or high cumulative exposure. Legubicin is an innovative drug developed using a Tumor Microenvironment-Activated (TMEA) strategy. Legubicin consists of doxorubicin as the payload, conjugated via a legumain-cleavable linker — which is specifically cleaved by legumain within the tumor microenvironment — to a moiety capable of covalently binding to albumin. With this design, activity-masked Legubicin remains relatively stable in normal tissues, and leverages tumor-enriched legumain as a 'biological switch' to selectively release the active drug locally within tumors. This preserves the potent antitumor activity of doxorubicin while reducing exposure to normal tissues and broadening the therapeutic window of conventional anthracyclines. Unlike traditional antibody-drug conjugates, which rely on binding to tumor cell surface antigens followed by internalization, drug release from Legubicin is primarily driven by the tumor microenvironment, providing an alternative technical pathway for the targeted delivery of classic cytotoxic agents.

Clinically Meaningful Antitumor Activity Observed in Previously Treated Advanced NSCLC; Positive Trends in PFS and OS

The Phase 1b/2a study presented at WCLC enrolled patients with advanced NSCLC who had received at least 3 lines of prior therapy or had no standard treatment options available. Subjects received monotherapy with Legubicin at 270 mg/m², administered once every 2 or 3 weeks.

This study enrolled 38 heavily pretreated patients with advanced non-small cell lung cancer (NSCLC) with no standard treatment options available in the late-line setting. 92.1% of subjects had received ≥3 lines of prior systemic therapy. Monotherapy with Legubicin yielded an objective response rate (ORR) of 7.9%, disease control rate (DCR) of 68.4%, median progression-free survival (mPFS) of 4.4 months, and median overall survival (mOS) of 15.0 months. In an indirect non-head-to-head comparison against historical control data for a similar second-line and beyond treated patient population, the mPFS was only 3.0 months, and mOS was only 10.3 months. Meanwhile, the drug demonstrates a favorable overall safety profile with low risk of cardiac toxicity. Compared with historical data, this study shows a trend of prolonged PFS and OS, alongside lower cumulative exposure to anthracyclines, supporting further development.

Further Advancement of Legubicin’s Clinical Development in Advanced NSCLC

The findings support the continued clinical development of Legubicin in NSCLC. Going forward, Affinity will advance the clinical development of Legubicin for lung cancer and other solid tumors and explore the potential of its proprietary TMEA technology to improve the therapeutic index of anticancer agents, reduce systemic toxicity, and broaden the scope of clinical applications. Based on the safety profile and preliminary efficacy signals observed in this Phase 1b/2a study, Affinity has been in discussions with CDE on the Phase III confirmatory clinical trial protocol for Legubicin in previously treated non-small cell lung cancer (NSCLC) and has received positive feedback.

About Affinity

Affinity (Shanghai) Biopharmaceutical Co., Ltd. (“Affinity”) develops and advances highly selective, low-toxicity innovative anticancer therapeutics built upon its proprietary first-in-class TMEA technology platform.

The Company strives to tackle the toxicity challenges of conventional chemotherapy and targeted therapies, address unmet medical needs in oncology, and transform traditional treatment modalities and reshape the paradigm of cancer care. Looking ahead, Affinity aims to become a fully integrated biopharmaceutical company with mature manufacturing and commercialization capabilities.

About Legubicin

Legubicin (QHL-108) is a Legumain-activated conjugate therapeutic developed from Affinity’s proprietary TMEA technology platform and is the world’s first Legumain-activated conjugate therapeutic. Its key registrational clinical trial has been completed. If approved, Legubicin is expected to become the world’s first approved conjugate therapeutic with a Topo II inhibitor (doxorubicin) as its payload. Multiple clinical studies of Legubicin are ongoing across a range of solid tumor indications.