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 therapy, 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.

Dose group 2 (6mg/kg) is expected to be fully recruited in August/September. Two patients in dose group 2 have progressive disease after completion of treatment. This means that so far, 67% of patients have responded positively to ODX treatment (transition from progressive disease to stable disease). No significant, ODX-related, side effects have been noted. Follow-up of all patients who have achieved stable disease is done to determine how long the disease-inhibiting effect persists after the ODX treatment has been discontinued. Follow-up of patients from dose group 1 shows that the disease-inhibiting effect continued, even after discontinuation of ODX. At most, the disease-inhibiting effect lasted just over six months without the initiation of other cancer treatment.

A meeting of the DMC (the independent data monitoring committee) is expected to be held in September to approve the continuation to dose group 3.

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 August 20, 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.