Zai Lab (ZLAB) Update / Briefing Transcript

Summary of Zai Lab (ZLAB) Update / Briefing June 02, 2025 Company and Industry Overview - Company: Zai Lab (ZLAB) - Industry: Oncology, specifically focusing on small cell lung cancer (SCLC) and DLL3 targeted therapies Key Points and Arguments Clinical Data and Efficacy - ZL1310: Investigational DLL3 targeted antibody-drug conjugate (ADC) showing promising clinical activity in patients with recurrent SCLC [4][8] - Patient Demographics: 89 patients enrolled in the trial, with 47% having one prior line of therapy and 53% having failed at least two prior lines [10] - Efficacy Results: - Confirmed overall response rate (ORR) of 68% and disease control rate (DCR) of 93% across all dose levels [14] - In second-line patients, ORR remains robust at 67% with a DCR of 97% [15] - Notably, the 1.6 mg/kg dose arm achieved an unconfirmed ORR of 79% and a 100% DCR [16] - Intracranial Activity: 68% ORR in patients with brain metastases, with 86% response in those without prior cranial radiation [21] Safety Profile - Safety Analysis: ZL1310 demonstrated a well-tolerated safety profile, with only 16% of patients in the low-dose group requiring dose interruptions [12] - Adverse Events: Most common treatment-related adverse events included anemia (40%), neutropenia (30%), and nausea (26%) [13] - High-Grade Adverse Events: Only 6% experienced grade three or greater toxicity in the lower dose group [12] Future Development Plans - Phase III Trial: A registrational study in second-line SCLC is planned to start later this year, comparing ZL1310 against investigator's choice of therapy [24][25] - Combination Studies: Exploring combinations with checkpoint inhibitors and chemotherapy, aiming to demonstrate competitive efficacy [40] - Expansion into Other Tumors: Plans to pursue opportunities in first-line SCLC and neuroendocrine carcinoma, targeting DLL3 expressing tumors [27] Regulatory Considerations - Accelerated Approval: Discussions with the FDA indicate potential for accelerated approval based on response rates in the randomized trial [58] - Study Design: The pivotal study will include patients with extensive stage SCLC who have progressed after first-line platinum-based therapy [25][66] Additional Important Insights - Therapeutic Window: The 1.6 mg/kg dose shows a promising balance of efficacy and tolerability, with ongoing discussions about dose optimization [33][34] - Durability of Response: Median follow-up for responders is 6.9 months, with a significant number of patients remaining in response [44] - Comparison with Competitors: ZL1310 is positioned as a more easily administered outpatient option compared to other therapies like pirilatumab, which may have logistical challenges [52] This summary encapsulates the critical findings and future directions for Zai Lab's ZL1310 program, highlighting its potential impact on the treatment landscape for small cell lung cancer.