On May 30, 2026 Whitehawk Therapeutics, Inc. (Nasdaq: WHWK), a clinical-stage oncology therapeutics company applying advanced technologies to established tumor biology to efficiently deliver improved antibody drug conjugate (ADC) cancer treatments, reported the presentation of a real world analysis supporting the therapeutic potential of targeting seizure related homolog protein 6 (SEZ6) with a next-generation ADC for the treatment of neuroendocrine tumors, including small cell lung cancer (SCLC). These data will be presented in a poster at the 2026 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting, being held May 29-June 2, 2026, in Chicago, Illinois.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

SEZ6 is a cell surface transmembrane protein involved in neuronal development that is primarily expressed in central nervous system (CNS) tissues. A large-scale RNA analysis demonstrated that SEZ6 is highly expressed across SCLC and other tumors of neuroendocrine origin. In SCLC, expression exceeds other approved and emerging ADC targets. SEZ6 expression is positively correlated with DLL3, indicating the potential for combination approaches with DLL3-targeted therapies. Together, these data support its potential as a clinically meaningful ADC target and reinforce the rationale for clinical development of HWK-206.

"SEZ6 demonstrates a compelling expression profile across SCLC and other neuroendocrine malignancies. In SCLC, it has levels of expression that are consistently high across disease stages and metastatic settings," said Afshin Dowlati, MD, University Hospitals Seidman Cancer Center and Case Western Reserve University. "The magnitude of SEZ6 expression relative to other therapeutic targets, along with its enrichment in neuroendocrine‑high SCLC subtypes, supports its potential as an ADC target."

Key Findings Include:

SEZ6 is highly expressed in SCLC and other tumors of neuroendocrine origin.
Expression exceeds other established and emerging ADC targets.
SCLC – SEZ6 expression was at least 3-fold higher than HER2, B7-H3, DLL3, PD-L1 and PD-1.
Prostate neuroendocrine carcinoma – SEZ6 expression was 2- to 6-fold higher than B7-H3, DLL3 and TROP2.
Among SCLC molecular subtypes, SEZ6 expression is highest in SCLC-A and SCLC-N, which accounts for ~90% of subtypes and are characterized by high expression of neuroendocrine transcription factors.
Expression is high across SCLC disease stages and metastatic status, supporting potential relevance across treatment settings.
Correlative expression in DLL3 supports combination strategies.
HWK-206 utilizes a dual epitope binding, or biparatopic, approach which can potentially improve binding and internalization of the ADC. In preclinical models, HWK-206 has demonstrated the potential to outperform other single epitope ADCs in development. An Investigational New Drug application to evaluate HWK-206 in SCLC and neuroendocrine tumors is expected to be submitted in mid-2026, with a Phase 1 start planned in Q3 2026.

"This real-world characterization of SEZ6 expression across small cell lung cancer and other neuroendocrine tumors reinforce our conviction in SEZ6 as a clinically meaningful target for ADC development," said Margaret Dugan, MD, Chief Medical Officer of Whitehawk Therapeutics. "These findings add to the body of evidence supporting our biparatopic SEZ6-directed ADC, HWK-206, and its potential to have a meaningful impact on patients with SCLC and neuroendocrine tumors."

Poster Presentation Details:

Title: Real-world characterization of SEZ6, a transmembrane protein expressed in various solid tumors
Poster: 219
Abstract: 3082
Presenter: Afshin Dowlati, MD, University Hospitals Seidman Cancer Center and Case Western Reserve University
Date & Time: May 30th, 2026, 1:30 – 4:30 PM CDT

The analysis was conducted as part of a previously announced collaboration between Whitehawk and Tempus AI. The posters will be accessible on the Presentations page of the Investors & News section of the Company’s website at www.whitehawktx.com.

(Press release, Whitehawk Therapeutics, MAY 30, 2026, View Source [SID1234666275])