Zai Lab's stock surged 5.11% during intraday trading on Thursday, reflecting strong investor optimism.

The rally follows the company's announcement that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to its potentially first-in-class Delta-like ligand 3 (DLL3)-targeting antibody-drug conjugate (ADC) zocilurtatug pelitecan (zoci) for the treatment of extra-pulmonary neuroendocrine carcinomas (epNECs). This designation is expected to accelerate the regulatory review process, highlighting the FDA's recognition of significant unmet clinical needs in this indication.

Clinical data presented at the AACR 2026 Annual Meeting from an ongoing Phase Ib/II study showed zoci achieved an objective response rate of 38.2% in heavily pretreated epNEC patients, with a manageable safety profile. The company is advancing the epNEC clinical program toward registration and has communicated regulatory filing plans with authorities.