Flexion Therapeutics, Inc. is an American biopharmaceutical company that specializes in the discovery, development, and commercialization of innovative, locally administered therapies for musculoskeletal conditions. Founded in 2007 and headquartered in Burlington, Massachusetts, Flexion Therapeutics has built its scientific focus around addressing unmet medical needs in osteoarthritis, the most common form of arthritis. Its flagship product, Zilretta, marked a significant advancement as the first FDA-approved extended-release intra-articular therapy for osteoarthritis-related knee pain, utilizing a novel microsphere technology for prolonged pain relief. Beyond Zilretta, Flexion's research portfolio includes FX201, an investigational gene therapy targeting long-term relief and potential disease modification in osteoarthritis, and FX301, a locally administered NaV1.7 inhibitor designed for use as a peripheral nerve block to control post-operative pain while preserving motor function. Flexion Therapeutics plays a notable role in the pharmaceutical sector, particularly within the orthopedic and pain management fields, striving to improve quality of life for patients suffering from chronic musculoskeletal disorders.