• SECN-15, a potential first-in-class antisense oligonucleotide (ASO), constitutes promising new treatment option for solid tumors
• Preclinical data substantiate enhanced anti-tumor immunity in monotherapy as well as in combination therapy setting with the potential to overcome resistance to checkpoint inhibitors

Martinsried (Munich), Germany, May 27, 2026 - Secarna Pharmaceuticals GmbH & Co. KG, a company redefining the discovery and development of best-in-class oligonucleotide therapeutics will present new preclinical and translational data for its proprietary lead program SECN-15, an antisense oligonucleotide (ASO) targeting the transmembrane protein Neuropilin-1 (NRP1), in a poster session at the American Society of Clinical Oncology (ASCO) Annual Meeting 2026 in Chicago, IL, USA, on Saturday, May 30, 2026.

“We feel privileged to once again present data on our lead program SECN-15 at the ASCO Annual Meeting, the world’s leading conference for clinical oncology,” said Konstantin Petropoulos, PhD, CEO of Secarna Pharmaceuticals. “Data generated for SECN-15 have shown a strong anti-tumor efficacy both as monotherapy and in combination with immune checkpoint inhibitors, ICIs, in multiple mouse tumor models. We can now add new pharmacodynamics data as we prepare for the first-in-human clinical trials.”

SECN-15 is Secarna’s proprietary ASO program in development, designed to selectively downregulate NRP1 expression, a promising target in oncology with the potential to break resistance to ICIs. Elevated NRP1 expression correlates with poor prognosis across multiple solid tumors and is associated with epithelial-mesenchymal transition (EMT), angiogenesis, fibrosis and the establishment of an immunosuppressive tumor microenvironment – key processes that drive tumor progression and resistance to currently approved immunotherapies. In tumor endothelial cells, for example, knockdown of NRP1 by SECN-15 is associated with reprogramming from an angiogenic to an immune-permissive, interferon-responsive state supporting a potential role in modulating the tumor microenvironment to enhance anti-tumor immunity.

A single injection of SECN-15 resulted in a sustained reduction of soluble NRP1 levels in vivo for at least 28 days, supporting durable target engagement. Soluble NRP1 levels in plasma will serve as a reliable and easily measurable biomarker for assessing NRP1 knockdown in subsequent clinical trials. While SECN-15 has the potential to target a broad range of solid tumors, patient-derived data suggest NRP1 to be a particularly promising target in gastric cancer, an area of significant unmet medical need, where treatment options remain limited and ICIs show poor efficacy. IND-enabling studies are currently underway to advance SECN-15 into clinical development for the treatment of solid tumors.

Poster Presentation Details
Title: Effects of SECN-15, a neuropilin-1-targeting antisense oligonucleotide, on resistance to immune checkpoint inhibitors in preclinical tumor models
Presenting Author: Konstantin Petropoulos, PhD, Chief Executive Officer, Secarna Pharmaceuticals
Abstract Number for Publication: 2613
Session Type/Title: Poster Session – Developmental Therapeutics – Immunotherapy
Poster Board: 403
Session Date: May 30, 2026
Session Time: 1:30 pm – 4:30 pm CDT

About Secarna Pharmaceuticals

Secarna Pharmaceuticals is a biopharmaceutical company redefining the discovery and development of best-in-class oligonucleotide therapeutics, offering hope to patients facing conditions that are beyond the reach of current approaches and modalities. With the Company’s proprietary AI-empowered OligoCreator® platform, which includes multiple delivery technologies, Secarna identifies and characterizes oligonucleotide therapeutics with unparalleled speed and excellent safety and efficacy. By delivering these novel therapeutics to the cells, organs, or tissues where they are needed, targeted oligonucleotide therapies have the potential to revolutionize treatments for a wide range of difficult-to-treat disorders. Secarna’s unique OligoCreator® platform is leveraged to transform untreatable conditions into treatable ones, profoundly changing the future of medicine. www.secarna.com