Flexion Therapeutics is a biopharmaceutical company focused on the discovery, development and commercialization of therapies for the treatment of patients with musculoskeletal conditions, beginning with osteoarthritis (OA), a type of degenerative arthritis. Co.'s product, ZILRETTA®, is an injection indicated for the management of OA knee pain. Co. has two product candidates focused on the treatment of musculoskeletal conditions: FX201 and FX301. FX201, is a gene therapy product candidate designed to provide on demand production of an anti-inflammatory protein, interleukin-1 receptor antagonist. FX301, is a NaV1.7 inhibitor formulated for extended release in a thermosensitive hydrogel.