• On track to file a Clinical Trial Application (CTA) by year end 2025, with initial clinical data expected mid-2026
• Important step in developing scalable and accessible ‘off-the-shelf’ cell therapy for patients with solid tumours

Oslo, Norway, 12 December, 2025 – Zelluna (OSE: ZLNA), a company pioneering allogeneic “off-the-shelf” T Cell Receptor-based Natural Killer (TCR-NK) cell therapies for the treatment of cancer, today announced the successful manufacture and QC (Quality Control) testing of the first GMP (Good Manufacturing Practice) batch of its lead candidate, ZI-MA4-1. This material is intended for use in Zelluna’s upcoming first-in-human clinical trial, marking a major milestone in the company’s progress toward regulatory submission and patient dosing.

The GMP batch was successfully produced using Zelluna’s proprietary manufacturing process, which was finalised and locked in April 2025. The process is designed to deliver high-quality TCR-NK products, with the ability to generate hundreds of doses from a single manufacturing run, offering both broad patient access and cost-of-goods advantages.

“Having our first GMP batch in storage and ready for our first clinical trial fills us with hope and excitement as we move closer to bringing our TCR-NK therapies to patients,” said Emilie Gauthy, Head of CMC at Zelluna. “This successful GMP run, backed by our robust development data, strengthens our confidence in delivering safe, potent, and consistent therapies at a scale capable of meeting patient’s needs.”

ZI-MA4-1 is the world’s first MAGE-A4-targeting TCR-NK therapy, designed to harness both the innate cancer-killing properties of NK cells and the precision targeting of affinity-enhanced TCRs. The therapy aims to overcome key challenges facing current cell therapies in solid tumours, including tumour heterogeneity and antigen loss, while offering an anticipated favourable safety profile and broad patient access.

“As we approach CTA submission, this achievement represents the final operational step on our path to the clinic,” said Namir Hassan, CEO of Zelluna. “Together with our compelling preclinical data showing ZI-MA4-1’s potent and selective activity in solid tumour models, this milestone underscores the strength of our science, our process, and our team. We believe ZI-MA4-1 is a highly differentiated therapy with the potential to redefine what is possible for patients with solid tumours. This is a proud and energising moment for everyone at Zelluna.”

Zelluna remains on track to submit a CTA for ZI-MA4-1 in 2H 2025 with initial clinical data expected mid-2026.

About Zelluna ASA

Zelluna ASA (OSE: ZLNA) is a biotechnology company pioneering the development of allogeneic ‘off-the-shelf’ T Cell Receptor-based Natural Killer (TCR-NK) cells for the treatment of cancer. The company’s platform combines the innate killing power of NK cells with the precision targeting of TCRs, designed to address the limitations of current cell therapies, particularly in solid tumours. Zelluna’s proprietary manufacturing process enables scalable, cost-effective production of TCR-NK cell therapies, with potential for broad patient accessibility. The company’s lead program, ZI-MA4-1, targets the MAGE-A4 tumour antigen and is expected to enter clinical trials in 2026. Zelluna is headquartered in Oslo, Norway.

For further information, please contact:

Namir Hassan, CEO, Zelluna ASA

Email: namir.hassan@zelluna.com

Phone: +44 7720 687608

For media enquiries, please contact:

Frazer Hall/Mark Swallow – MEDiSTRAVA

Email: zelluna@medistrava.com

This information is considered to be inside information pursuant to the EU Market Abuse Regulation and is subject to the disclosure requirements pursuant to Section 5-12 in the Norwegian Securities Trading Act.

This stock exchange announcement was published by Joachim Midttun, Finance manager of Zelluna ASA, on 12 December 2025 at 12.58 CET.