Flexion (Burlington, Massachusetts) has submitted a new drug application (NDA) to the US Food and Drug Administration (FDA) for Zilretta™ (FX006), a potential treatment for patients with osteoarthritis (OA) of the knee. This intra-articular, extended-release treatment combines triamcinolone acetonide (TA) with a poly lactic-co-glycolic acid (PLGA) matrix.

The NDA is supported by results from a randomized, double blind, placebo and active-comparator (immediate-release TA) controlled trial. A total of 484 patients were enrolled in the study for 12 weeks. Results showed that Zilretta demonstrated a highly significant (<.0001) reduction in average daily pain versus placebo at week 12 (primary endpoint), with durable and clinically meaningful pain relief in patients with moderate to severe OA knee pain. 

Also, compared to immediate-release TA, the Zilretta-treated group had statistically significant improvements in Western Ontario and McMaster Universities Arthritis Index (WOMAC) A1 (pain), WOMAC B (stiffness) and WOMAC C (function). 

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The most common adverse events for Zilretta with an incidence rate ≥2% were arthralgia, headache, joint swelling and back pain. No serious drug-related adverse events were observed.

Zilretta was granted Fast Track status by the FDA in 2015.

“Based on our pivotal data, we believe that Zilretta has the potential to be the first intra-articular, extended-release treatment for the many millions of patients who suffer with knee OA,” said Michael Clayman, MD, President and CEO of Flexion. 

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Flexion therapeutics submits new drug application for Zilretta™ to treat knee osteoarthritis pain. [news release]. Burlington, MA. Flexion Therapetics.  Accessed December 15, 2016.

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This article originally appeared on MPR