The FDA granted Fast Track Designation to Zai Lab’s DLL3-targeting ADC zocilurtatug pelitecan (zoci, ZL-1310) for previously treated extrapulmonary neuroendocrine carcinomas (epNECs). Preliminary Phase 1b/2 data showed a 38.2% objective response rate in heavily pretreated patients, with manageable safety findings.
Written By: Sana Khan, BPharm
Reviewed By: Pharmacally Editorial Team
Zai Lab announced that the U.S. Food and Drug Administration has granted Fast Track Designation to zocilurtatug pelitecan (zoci, formerly ZL-1310) for the treatment of extrapulmonary neuroendocrine carcinomas (epNECs) in patients whose disease has progressed after standard first-line therapy.
The Fast Track designation was supported by preliminary findings from an ongoing registration-enabling multicenter Phase 1b/2 trial (NCT06885281) evaluating zoci in patients with epNEC and other selected solid tumors. Data presented at the American Association for Cancer Research (AACR) Annual Meeting 2026 showed encouraging antitumor activity in heavily pretreated patients, with an objective response rate of 38.2%.
The study also demonstrated a manageable safety profile. Neutrophil count decrease was the only grade 3 or higher treatment-related adverse event reported in more than one patient.
Rafael G. Amado, M.D., President and Head of Global Research and Development at Zai Lab, said the designation highlights the potential of zoci to address difficult-to-treat cancers with limited available therapies. He added that the company is continuing discussions with regulatory authorities regarding a potential registrational strategy for epNECs.
This marks the second FDA Fast Track Designation for zoci. In May 2025, the investigational therapy also received Fast Track status for the treatment of extensive-stage small cell lung cancer (ES-SCLC).
Fast Track designation is intended to facilitate the development and review of therapies for serious conditions with unmet medical needs. The program allows for more frequent interactions with the FDA and may provide eligibility for Accelerated Approval and Priority Review if regulatory criteria are met.
Zai Lab stated that zoci remains on track for three planned registration-enabling studies across second-line SCLC, first-line SCLC, and epNEC by the end of 2026.
Zocilurtatug pelitecan (zoci; ZL-1310) is an investigational DLL3-targeting antibody-drug conjugate (ADC) being developed by Zai Lab for small cell lung cancer (SCLC) and other neuroendocrine tumors. Early clinical data have shown encouraging antitumor activity, including meaningful intracranial responses in previously treated extensive-stage SCLC patients with brain metastases. The promising findings have supported broader development efforts, including a clinical collaboration between Boehringer Ingelheim and Zai Lab to evaluate zoci in combination with obrixtamig in hard-to-treat cancers.
epNECs are aggressive neuroendocrine malignancies with limited treatment options and no approved standard of care in previously treated disease settings. According to the company, the disease affects approximately 100,000 people worldwide.
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About the Writer
Sana Jamil Khan (LinkedIn) is a B. Pharm graduate with a strong interest in medical writing and scientific communication. Her work focuses on interpreting clinical research, exploring developments in pharmaceutical science, and presenting complex medical information in a clear and accessible manner. She is particularly interested in topics related to human clinical studies, drug safety observations, and emerging therapeutic research.