Flexion Therapeutics Announces Inclusion of ZILRETTA® in American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guidelines for the Management of Osteoarthritis of the Knee

  • AAOS finds that ZILRETTA (triamcinolone acetonide extended-release injectable suspension) can improve patient outcomes over immediate-release corticosteroids

BURLINGTON, Mass., Sept. 02, 2021 (GLOBE NEWSWIRE) -- Flexion Therapeutics Inc. (Nasdaq:FLXN) announced that the American Academy of Orthopaedic Surgeons (AAOS) included ZILRETTA (triamcinolone acetonide extended-release injectable suspension) in its updated evidence-based clinical practice guidelines for the management of osteoarthritis (OA) of the knee.1

The AAOS guidelines reflect a moderate recommendation for the use of intra-articular (IA) corticosteroids for patients with symptomatic OA of the knee. The recommendation follows a review of data from 25 studies assessing IA corticosteroids. Included in its rationale is a differential analysis of extended-release intra-articular steroid, of which ZILRETTA is the only available product, versus immediate-release IA corticosteroids, where AAOS analyses demonstrated that it can, “be used over immediate-release corticosteroids to improve patient outcomes.”

“We are very pleased that the AAOS data review has determined that ZILRETTA can play a differentiated role in the treatment of OA knee pain,” said Michael Clayman, M.D., President and Chief Executive Officer of Flexion. “This supports our belief that ZILRETTA is an important option for the millions of people who confront OA knee pain every year.”

Andrew I. Spitzer, M.D., Professor of Orthopaedic Surgery, Clinical Chief, Department of Orthopaedic Surgery, Co-Director, Joint Replacement Program, Cedars-Sinai Department of Orthopaedic Surgery added, “I believe these guidelines acknowledge the quality of data surrounding the efficacy and safety of ZILRETTA and offer healthcare providers who treat patients with knee OA added confidence to further incorporate ZILRETTA into their clinical practice.”  

The AAOS guidelines serve as an educational tool to help guide clinical treatment decisions to improve the quality and effectiveness of care and were last revised in 2013.

Indication and Select Important Safety Information for ZILRETTA

Indication: ZILRETTA is indicated as an intra-articular injection for the management of osteoarthritis pain of the knee.

Limitation of Use: The efficacy and safety of repeat administration of ZILRETTA have not been demonstrated.

Contraindication: ZILRETTA is contraindicated in patients who are hypersensitive to triamcinolone acetonide, corticosteroids or any components of the product.

Warnings and Precautions:

  • Intra-articular Use Only: ZILRETTA has not been evaluated and should not be administered by epidural, intrathecal, intravenous, intraocular, intramuscular, intradermal, or subcutaneous routes. ZILRETTA should not be considered safe for epidural or intrathecal administration.
  • Serious Neurologic Adverse Reactions with Epidural and Intrathecal Administration: Serious neurologic events have been reported following epidural or intrathecal corticosteroid administration. Corticosteroids are not approved for this use.
  • Hypersensitivity reactions: Serious reactions have been reported with triamcinolone acetonide injection. Institute appropriate care if an anaphylactic reaction occurs.
  • Joint infection and damage: A marked increase in joint pain, joint swelling, restricted motion, fever and malaise may suggest septic arthritis. If this occurs, conduct appropriate evaluation and if confirmed, institute appropriate antimicrobial treatment.

Adverse Reactions: The most commonly reported adverse reactions (incidence ≥1%) in clinical studies included sinusitis, cough, and contusions.

Please see ZilrettaLabel.com for full Prescribing Information.

On October 6, 2017, ZILRETTA was approved by the U.S. FDA as the first and only extended-release intra-articular therapy for patients confronting osteoarthritis-related knee pain. ZILRETTA employs proprietary microsphere technology combining triamcinolone acetonide — a commonly administered, short-acting corticosteroid — with a poly lactic-co-glycolic acid (PLGA) matrix to provide extended pain relief. The pivotal Phase 3 trial on which the approval of ZILRETTA was based showed that ZILRETTA significantly reduced OA knee pain for 12 weeks. Learn more at www.zilretta.com.

About Flexion Therapeutics
Flexion Therapeutics (Nasdaq:FLXN) is a biopharmaceutical company focused on the development and commercialization of novel, local therapies for the treatment of patients with musculoskeletal conditions, beginning with osteoarthritis, the most common form of arthritis. The company's core values are focus, ingenuity, tenacity, transparency and fun. Please visit flexiontherapeutics.com

Forward-Looking Statements
This press release contains forward-looking statements that are based on the current expectations and beliefs of Flexion. Statements in this press release regarding matters that are not historical facts, including, but not limited to, statements relating to the future of Flexion; and the potential therapeutic and other benefits of ZILRETTA, are forward looking statements. These forward-looking statements are based on management’s expectations and assumptions as of the date of this press release and are subject to numerous risks and uncertainties, which could cause actual results to differ materially from those expressed or implied by such statements. These risks and uncertainties include, without limitation, the fact that the impacts and expected duration of the COVID-19 pandemic are uncertain and rapidly changing; the risk that we may not be able to maintain and enforce our intellectual property, including intellectual property related to ZILRETTA; and other risks and uncertainties described in our filings with the Securities and Exchange Commission (SEC), including under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021 and subsequent filings with the SEC. The forward-looking statements in this press release speak only as of the date of this press release, and we undertake no obligation to update or revise any of the statements. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release.



Scott Young
Vice President, Corporate Communications & Investor Relations
Flexion Therapeutics, Inc.
T: 781-305-7194

Julie Downs
Associate Director, Corporate Communications & Investor Relations
Flexion Therapeutics, Inc.
T: 781-305-7137

  1. American Academy of Orthopaedic Surgeons Management of Osteoarthritis of the Knee (Non-Arthroplasty) Evidence-Based Clinical Practice Guideline. https://www.aaos.org/OAK3CPG 

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