Flexion Therapeutics Enrolls First Patient in Pharmacokinetic Study of Zilretta™ for Osteoarthritis of the Knee

Flexion Therapeutics, Inc.

announced today that it has enrolled its first patient in a pharmacokinetic (PK) study of Zilretta (also known as FX006). In this open-label, single administration clinical trial, researchers at four U.S. sites will study 40 mg of Zilretta administered as a single 5 mL intra-articular (IA) injection in 50 patients with osteoarthritis (OA) of the knee. The objective of the study is to provide additional characterization of the local concentrations of triamcinolone acetonide (TCA, or the active ingredient in Zilretta) in the knee over 20 weeks following a single injection. OA is a painful and debilitating musculoskeletal disease that is characterized by IA inflammation, deterioration of articular cartilage, and degenerative changes to joint architecture. The incidence of OA is increasing rapidly, and the condition is expected to affect 45 million Americans by 2030. Current treatment options – including opioids and common anti-inflammatory medicines – are not always effective, and many carry serious risks and side effects. "This study is being conducted in support of our planned New Drug Application (NDA) submission to the FDA, and is designed to determine the concentration of drug in the synovial fluid and plasma of patients with OA at multiple time points," said Michael Clayman, M.D., Flexion Therapeutics President and Chief Executive Officer. "We anticipate making the NDA submission during the second half of 2016, and we continue to look forward to positioning Zilretta as a potential first-in-class IA treatment for patients with moderate to severe OA, providing them with a non-opioid, sustained-release pain therapy." Zilretta is intended to provide an extended-release of the TCA formulation over a three-month period into the patient's synovial and peri-synovial tissues. Due to the large unmet need among OA patients, the FDA recently granted Zilretta with Fast Track designation.