The study is being conducted at Karolinska University Hospital Huddinge and at Uddevalla Hospital. The treatment lasts for a total of 14 weeks with 2 doses per month. Three dose levels of ODX are studied, 3mg/kg body weight, 6mg/kg, and 9mg/kg. The Principal Investigator (PI) is Dr Katarina Uttervall, MD, PhD, Department of Hematology/HERM, Karolinska University Hospital Huddinge. Dr Dorota Knut is the principal investigator at the Department of Hematology at Uddevalla Hospital. Analysis of biomarkers takes place at the Central Laboratory, Karolinska University Hospital Solna, NKS.  Adult myeloma patients with progressive, treatment-resistant, disease, who have previously received 1–5 prior lines of treatment are included in the study. The primary objective is to confirm ODX safety and tolerability and with a secondary objective to demonstrate indications of treatment response.

The last patient in dose group 2 (6mg/kg) is expected to be finished at week 50 (7 doses). After 6 doses, the patient has still maintained their achieved stable disease, i.e. the progression verified prior to the start of treatment has stopped. The other 3 patients in dose group 2 have, after completion of ODX treatment and the disease was stable, now returned to their progressive disease.

The first patient in dose group 3 (9mg/kg) has received 3 doses to date. Here, too, the progressive disease has turned into a stable one. A further 2 patients in dose group 3 have only recently started their ODX treatment.

This means that so far, 9/9 (100%) of patients have responded positively to ODX treatment (transition from progressive disease to stable disease). The patients are followed as planned after completion of ODX treatment; this is to map when the disease progresses again. The disease-inhibiting effect persists in some cases even after postponed ODX treatment, at most up to six months.

"Overall, the results are remarkable and far better than we dared to hope for. The fact that the disease-inhibiting effect persists even after the end of ODX treatment is surprising. I believe that the results will arouse interest in ODX for the indication of multiple myeloma, in addition with the absence of serious side effects," says CEO Anders R Holmberg.

For more information about DexTech, please contact:

Gösta Lundgren – CFO

DexTech Medical AB

Phone: +46 (0) 707104788

E-mail: gosta.lundgren@dextechmedical.com

This information is information that DexTech Medical AB is obliged to make public pursuant to the EU Market Abuse Regulation. The information was submitted for publication, through the agency of the contact person set out above, on December 3, 2025.

DexTech Medical AB is a Swedish research company that, based on its technology platform, has developed four drug candidates that are protected by patents. The lead candidate is OsteoDex for the treatment of castration-resistant prostate cancer (CRPC) with bone metastases. A successful clinical phase II study has been conducted with OsteoDex where the results show high tolerability with mild side effects and treatment effect on patients who fail existing drugs. DexTech''s goal is to out-license each drug candidate no later than after completion of the phase II study. DexTech Medical AB is listed on the Spotlight Stock Market.