Synartro – completed treatment of all four cohorts in phase 1/2a clinical study of SYN321

Synartro AB announces that it has completed the treatment of all four cohorts in its phase 1/2a clinical study of SYN321.

Synartro is advancing the candidate drug SYN321, a novel intra-articular treatment for knee osteoarthritis, through a phase 1/2a clinical trial focused on safety, tolerability, PK, and early efficacy signals. The trial began on September 1st, 2025, and is being carried out in partnership with CTC at Uppsala University Hospital, with study completion anticipated in the spring of 2026.

Following evaluation by the study’s internal safety review committee, the highest dose was selected for the fourth cohort, in which twelve participants were treated, bringing the total number of participants dosed in the clinical trial to thirty-five. With this, all four cohorts have now been successfully dosed. The first and second cohorts have completed their participation in the study, while the third cohort is expected to complete the study during this week. The fourth cohort is expected to complete the study in February 2026.

For further information, please contact:

Magnus Hurst, CFO & acting CEO. Tel: +46 (0) 760 27 44 27. E-mail: magnus.hurst@synartro.com

About Synartro AB

Synartro is a Swedish life science company developing local injection treatments that provide superior and sustained efficacy without systemic side-effects. This is achieved by combining our proprietary slow-release technology with existing proven drugs. Our lead candidate drug SYN321 is a novel treatment of symptomatic osteoarthritis (OA). A disease that leaves hundreds of millions of patients without adequate pain relief.

In addition to the founders, major shareholders include life science investment company Linc AB.