The Food and Drug Administration (FDA) has granted Fast Track designation to pentosan polysulfate sodium (PPS; Zilosul) for the treatment of osteoarthritis (OA).

PPS is a semi-synthetically produced heparin-like macromolecular carbohydrate derivative, which chemically and structurally resembles glycosaminoglycans. In preclinical studies, PPS was observed to reduce inflammation and prevent cartilage degradation.

The Company is currently enrolling adults with knee OA pain in a 2-stage, adaptive, randomized, double-blind, placebo-controlled, phase 3 trial (PARA_OA_002; Identifier: NCT04809376). The study will evaluate the change from baseline in pain and function with subcutaneous injections of PPS. 

A phase 3 follow-up extension study ( Identifier: NCT04814719) is also being planned for patients who complete the PARA_OA_002 study in order to assess the duration of effect and need for retreatment.

Commenting on the FDA designation, Dr Donna Skerrett, Paradigm Chief Medical Officer and Interim CEO, said, “This is welcome news from the FDA as the company continues to gain momentum in site activation and participant screening across the 56 selected sites in the US.”


  1. FDA grants Fast Track designation for Paradigm Biopharmaceuticals phase III osteoarthritis program. News release. Paradigm Biopharmaceuticals. Accessed April 13, 2022.
  2. Our focus: PPS. Paradigm Biopharmaceuticals. Accessed April 13, 2022.