Zai Lab’s DLL3-Targeting ADC Zoci Gains FDA Orphan Drug Status for Neuroendocrine Carcinomas — Zai Lab Limited

Event summary

The U.S. FDA granted Orphan Drug Designation to Zai Lab’s zocilurtug pelitecan (Zoci) for treating neuroendocrine carcinomas (NECs).
Zoci is a DLL3-targeting antibody-drug conjugate with no approved standard of care for previously treated NEC patients.
The designation provides development incentives, including tax credits and potential seven-year market exclusivity upon approval.
Zai Lab plans three registration-enabling studies for Zoci by the end of 2026 across SCLC and epNEC indications.

The big picture

Zai Lab’s Zoci represents a strategic push into the high-unmet-need area of neuroendocrine carcinomas, leveraging its DLL3-targeting mechanism to potentially redefine treatment standards. The FDA’s Orphan Drug Designation underscores the therapeutic gap in NECs and positions Zoci as a key player in Zai Lab’s global oncology ambitions. Success hinges on efficient clinical execution and regulatory maneuvering.

What we're watching

Clinical Progress: The pace at which Zai Lab advances its registration-enabling studies for Zoci will determine its commercial viability.
Regulatory Strategy: How the FDA’s Orphan Drug Designation and prior Fast Track designation influence Zoci’s approval pathway and market positioning.
Competitive Dynamics: Whether Zoci can establish itself as a best-in-class therapy in the DLL3-targeting ADC space amid existing treatments for SCLC and NECs.