FX.co ★ Zai Lab Gets FDA Orphan Drug Designation For ZL-1310 To Treat Small Cell Lung Cancer

Zai Lab Limited (ZLAB) has announced that the U.S. Food and Drug Administration (FDA) has awarded Orphan Drug Designation (ODD) to ZL-1310, a pioneering DLL3 antibody-drug conjugate (ADC), for the treatment of small cell lung cancer (SCLC).

This decision was driven by encouraging results from Zai Lab's ongoing global Phase 1a/1b clinical trial, which assesses ZL-1310 both as a standalone treatment and in combination with atezolizumab, an immune checkpoint inhibitor, for patients with extensive-stage SCLC (ES-SCLC).

The ODD status affords ZL-1310 access to various development benefits, such as a waiver of the application fee under the Prescription Drug User Fee Act, tax credits for specific clinical trials, and the potential for a seven-year period of market exclusivity in the U.S. upon approval.

Currently, treatment options for SCLC, one of the most aggressive and fatal solid tumors, remain limited.

ZL-1310 is a unique ADC targeting Delta-like ligand 3 (DLL3), an antigen commonly overexpressed in numerous neuroendocrine tumors and linked to poor clinical outcomes. DLL3 is a confirmed therapeutic target for SCLC.

ZL-1310 features a humanized anti-DLL3 monoclonal antibody attached to a novel camptothecin derivative, which serves as a topoisomerase 1 inhibitor. The compound was crafted using the innovative TMALIN platform, which utilizes the tumor microenvironment to address challenges faced by earlier ADC therapies, including off-target payload toxicity.

Rafael Amado, President and Head of Global Research and Development at Zai Lab, commented, "The Orphan Drug Designation for ZL-1310 acknowledges its potential to address the urgent need for effective, safe, and widely accessible treatment options for SCLC patients in both tertiary and community care settings. Recent data from our Phase 1 trial in recurrent SCLC patients have shown promising objective response rates and a favorable safety profile."

Zai Lab plans to further the clinical development of ZL-1310 across various treatment lines for SCLC and other tumors expressing DLL3.