Technology & Portfolio

Technology & Portfolio

Unique drug delivery technology

Synartro develops improved injection treatments using a patented drug delivery technology that enables a sustained drug release. By locally injecting the treatment, a very low dose of the active substance is needed. For other indications where local slow release of compounds with systemic safety concerns is beneficial, our delivery technology could provide significant improvement.  

Lead program, SYN321

Drug candidate SYN321 is an intraarticular injection, containing diclofenac and hyaluronan, in development for the treatment of knee OA. It is the unique binding between diclofenac and hyaluronan that enable therapeutic benefits of SYN321 such as reduced side effects, prolonged pain relief as well as reduction of inflammation and pain. Compared with other treatments, considerably less SYN321 substance is needed for desired efficacy. SYN321 also has disease-modifying potential, which could slow down or, in best case, stop the disease progression entirely.

SYN321 has the potential to become the preferred second-line treatment for knee OA.


The next step for SYN321 is a first-in-human trial. This trial will focus on safety and exploratory efficacy of SYN321. Synartro plans to manufacture product and file for approval for the trial with relevant authorities in 2022.

In the preclinical stage of SYN321 a study in horses was completed at the Swedish University of Agricultural Sciences, SLU. The results from the study showed very good tolerability and favorable pharmacokinetics. The preclinical program has covered several studies giving further information on the characteristics of SYN321.

Other steps that have been performed are to manufacture the substance under GMP conditions and toxicological safety studies.


The patent filed by Synartro in 2015 was initially approved in the US in May 2020 and in Europe in December 2021. The patent is a compound patent, covering the unique platform of hyaluronan and a linker, that can be connected to different pharmaceutical active substances. Thus, the patent protects not only SYN321, but also other compounds based on the platform.

The patent is valid until 2035, with a possible extension of five years. It is the company’s assessment that the patent provides strong immaterial protection.