EU Patent Win Strengthens Persica’s Global Grip on PP353

The newly granted European patent, EP3709970, covers the formulation and use of PP353, a novel injectable, thermosensitive hydrogel containing linezolid—an antibiotic known for its effectiveness against gram-positive bacteria. PP353 is currently being developed for the treatment of chronic low back pain (cLBP) associated with Modic Type 1 changes, a specific type of vertebral bone marrow inflammation linked to bacterial infection in intervertebral discs.

This patent grant adds to Persica’s expanding international IP portfolio, which already includes granted patents in the United States, Japan, and China, securing protection for PP353 in key global markets. With this European patent, Persica now holds intellectual property coverage across four of the largest healthcare markets in the world, enhancing its ability to commercialize PP353 on a broad scale and protect its proprietary formulation until 2038.

According to Persica, the patent includes claims for the specific composition of the hydrogel as well as methods of treating discogenic back pain using the formulation. The technology combines linezolid, a radio-opaque dye, and a thermosensitive biodegradable polymer that solidifies upon reaching body temperature, allowing for sustained release of the antibiotic directly into the infected disc area. This targeted and extended-release approach aims to offer non-opioid, localized pain relief, while addressing the bacterial infection believed to be a root cause of Modic Type 1 changes.

The significance of this development is twofold. From a scientific perspective, the grant validates the uniqueness of PP353’s formulation and its therapeutic approach. From a business standpoint, it positions Persica to defend its innovations more effectively against competitors while laying a strong foundation for partnerships, licensing, or future commercialization opportunities within the European Union.

Earlier in 2025, Persica reported promising results from a Phase 1b clinical study of PP353, demonstrating safety, tolerability, and a significant improvement in pain and disability metrics among trial participants over a 12-month period. The combination of clinical progress and robust IP protection enhances the therapy’s potential to meet a critical unmet need in chronic back pain management.