STOCKHOLM, Sweden, December 11, 2025. Karolinska Development AB (Nasdaq Stockholm: KDEV) announces that its portfolio company SVF Vaccines has presented new preclinical data on its immunotherapy SVF-001, targeting hepatitis B and D, as a late-breaking abstract at the HepDart scientific meeting held December 7-11 in Honolulu, Hawaii. The results are follow-up data from a previously reported study, showing extended antiviral effect in preclinical models.

SVF Vaccines develops DNA vaccines and immunotherapies based on proprietary technology originating from Karolinska Institutet. New data from the SVF-001 preclinical program demonstrate apparent antiviral activity of the antibody treatment up to six weeks after treatment. The data on the extended effect are based on a follow-up analysis in a previously reported preclinical study, showing sustained reductions of hepatitis D virus RNA in the blood through the six-week follow-up period.

The data support SVF Vaccines’ goal for SVF-001 to achieve strong and long-lasting immunological control of hepatitis B and hepatitis D in patients with chronic coinfections. The data was presented by one of SVF Vaccines’ founders, Matti Sällberg, as a late-breaking abstract at the HepDart scientific meeting in December.

"It’s very promising to see not only a therapeutic response but also a durable antiviral effect of SVF-001 in this preclinical program. We look forward to continuing to follow this potentially new immunotherapy that has a great chance to offer a cure for patients with chronic hepatitis B and D coinfection," says Viktor Drvota, CEO of Karolinska Development.

SVF Vaccines’ portfolio includes SVF-001, a therapeutic immunotherapy for chronic hepatitis B and D, SVF-002, a universal prophylactic vaccine against COVID-19, and early-stage discovery programs for other serious infectious diseases.

Karolinska Development's ownership in SVF Vaccines amounts to 33 percent.

For further information, please contact:

Viktor Drvota, CEO, Karolinska Development AB
Phone: +46 73 982 52 02, e-mail: viktor.drvota@karolinskadevelopment.com

Johan Dighed, General Counsel and Deputy CEO, Karolinska Development AB
Phone: +46 70 207 48 26, e-mail: johan.dighed@karolinskadevelopment.com

TO THE EDITORS

About Karolinska Development AB

Karolinska Development AB (Nasdaq Stockholm: KDEV) is a Nordic life sciences investment company. The company focuses on identifying breakthrough medical innovations in the Nordic region that are developed by entrepreneurs and leadership teams. The Company invests in the creation and growth of companies that advance these assets into commercial products that are designed to make a difference to patient’s lives while providing an attractive return on investment to shareholders.

Karolinska Development has access to world-class medical innovations at the Karolinska Institutet and other leading universities and research institutes in the Nordic region. The Company aims to build companies around scientists who are leaders in their fields, supported by experienced management teams and advisers, and co-funded by specialist international investors, to provide the greatest chance of success.

Karolinska Development has a portfolio of eleven companies targeting opportunities in innovative treatment for life-threatening or serious debilitating diseases.

The Company is led by an entrepreneurial team of investment professionals with a proven track record as company builders and with access to a strong global network.

For more information, please visit www.karolinskadevelopment.com.