Paradigm Biopharmaceuticals (ASX:PAR) said that the first US clinical sites participating in its phase 3 PARA_OA_012 study were activated, and the first US patients provided informed consent and entered the screening process for participation in the study, according to a Monday Australian bourse filing.

The study will test injectable pentosan polysulfate sodium for the treatment of moderate-to-severe knee osteoarthritis. The primary endpoint is the change from baseline in average daily pain at day 112. Secondary endpoints include WOMAC scores for pain and physical function, PGIC, rescue medication use, and structural joint assessments via MRI and X-ray imaging.

First randomization and dosing are expected in the coming weeks.

Its shares fell over 4% on market close on Monday.