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Additional Positive Preclinical Proof-Of-Concept Results for the HER2-CVLP Breast Cancer Vaccine

Hørsholm, Denmark, May 25, 2022 – ExpreS2ion Biotech Holding AB's affiliate ExpreS2ion Biotechnologies ApS (“ExpreS2ion") announces that the capsid virus-like particle (cVLP) HER2-breast cancer vaccine candidate ES2B-C001 has demonstrated additional positive proof-of-concept also in a metastatic outgrowth therapeutic tumor mice model. These data support the already established preclinical proof-of-concept results announced in December 2021 and January 2022.

The additional topline preclinical results reported today by ExpreS2ion are based on data from a new therapeutic study in HER2-transgenic mice that were injected intravenously with HER2-positive tumors upon which vaccination every two weeks were initiated one week after challenge. All control mice had lung nodules, whereas all mice vaccinated with ES2B-C001 formulated in an adjuvant were metastasis-free. Furthermore, 73% of mice vaccinated with ES2B-C001 without adjuvant were metastasis-free, the remaining had only 1-2 lung nodules.

The data will be presented at the Oncology webinar hosted by H.C. Andersen Capital on May 31 at 10:00 CET. Information and registration can be found on the H.C. Andersen Capital events website.

ExpreS2ion continues on path to bring ES2B-C001 towards the first clinical trial in 2024 and is currently working on the GMP manufacturing process development, as well as has initiated the preclinical safety studies as advised by DKMA (the Danish Medicines Agency) earlier this year.

CEO Bent Frandsen comments:

“It is very pleasing that we in a preclinical setting continue to demonstrate excellent results, which advances our ES2B-C001 breast cancer vaccine candidate towards a first in human trial in 2024.”

About ES2B-C001 and breast cancer

Breast cancer is a widespread oncology indication affecting more than 1.3 million people worldwide annually, resulting in more than 450,000 deaths (Tao, 2015: www.ncbi.nlm.nih.gov/pubmed/25543329). The most common treatment today is based on monoclonal antibodies, where the dominating therapy Herceptin (trastuzumab) generates annual global sales of USD 7 billion. The target product profile of the HER2-cVLP breast cancer vaccine candidate is tailored to be highly competitive both in terms of cost and efficacy, thus aiming at a significant market share.

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This press release constitutes inside information that ExpreS2ion Biotech Holding AB (publ) is obliged to make public pursuant to the EU Market Abuse Regulation 596/2014. The information was sent for publication, through the agency of the contact persons set out above, at the time stated by the Company's news distributor, Cision, at the publication of this press release.

For further information about ExpreS2ion Biotech Holding AB, please contact:

Bent U. Frandsen, CEO
Telephone: +45 4256 6869
E-mail: [email protected]

Keith Alexander, CFO
Telephone: +45 5131 8147
E-mail: [email protected]

About ExpreS2ion

ExpreS2ion Biotechnologies ApS is a fully owned Danish subsidiary of ExpreS2ion Biotech Holding AB with company register number 559033-3729. ExpreS2ion has developed a unique technology platform, ExpreS2, for fast and efficient non-clinical development and production of complex proteins for new vaccines and diagnostics. ExpreS2 is regulatorily validated for clinical supply. The platform includes functionally modified glycosylation variants for enhanced immunogenicity and pharmacokinetics. Since 2010, the Company has produced more than 500 proteins and virus-like particles (VLPs) in collaboration with leading research institutions and companies. ExpreS2ion develops novel VLP based vaccines in association with AdaptVac ApS, of which ExpreS2ion owns 34%. For additional information, please visit www.expres2ionbio.com.