Zai Lab reports 81.8% response rate in lung cancer trial

Zai Lab (NASDAQ:ZLAB) reported an 81.8% confirmed tumor response rate in a Phase 1b trial of zocilurtatug pelitecan plus atezolizumab for first-line treatment of extensive-stage small cell lung cancer.

The combination produced an estimated six-month progression-free survival rate of 81.9% among 33 patients treated at the recommended dose of 1.6 mg/kg, although median progression-free survival had not yet been reached.

“The high confirmed response rate, encouraging durability, and well-tolerated safety profile we are seeing with a standard chemotherapy-free regimen are particularly compelling,” said Zai Lab President and Head of Global Research and Development Rafael G. Amado.

Among the 33 patients receiving the doublet regimen, three experienced Grade 3 or higher adverse events related to zoci, representing 9.1%, and no patients discontinued treatment because of treatment-related adverse events.

Zai Lab plans to initiate a global randomized Phase 3 trial of zoci combined with an immunotherapy regimen in first-line extensive-stage small cell lung cancer by the end of 2026, subject to clinical development and regulatory requirements.

A separate group of 13 patients receiving zoci, atezolizumab and carboplatin across multiple dose levels recorded a 92.3% response rate, but Grade 3 or higher treatment-emergent adverse events occurred in 76.9% of this group.

Zai Lab is a biopharmaceutical company developing medicines for oncology, immunology, neuroscience and other disease areas, with the zoci program focused on advancing treatment options for small cell lung cancer.