Zilretta Labeling Updated to Include Information Pertaining to Repeat Administration

The Food and Drug Administration has approved a supplemental New Drug Application (sNDA) to update the product labeling for Zilretta (triamcinolone acetonide extended-release injectable suspension; Flexion Therapeutics) for the management of osteoarthritis (OA) knee pain.

Zilretta combines triamcinolone acetonide, a short-acting corticosteroid, with a poly lactic-co-glycolic acid (PLGA) matrix to be administered by intra-articular injection. The updated prescribing information includes:

• An updated Limitation of Use statement: “The efficacy and safety of repeat administration of Zilretta have not been demonstrated.” Previously, the labeling stated that the treatment was not intended for repeat administration.
• Inclusion of a study describing a single-arm, open-label phase 3 repeat administration trial.
• Removal of a misleading statement describing a single secondary exploratory end point in the original phase 3 pivotal trial which compared Zilretta to immediate-release triamcinolone acetonide crystalline suspension.
• Inclusion of nonclinical toxicology data from previously submitted single and repeat administration studies in non-diseased animals.

The efficacy and safety of repeat administration of Zilretta were evaluated in a multicenter, open-label, single-arm study in patients with osteoarthritis pain of the knee. A total of 179 patients received a repeat injection on or after Week 12 (median time to second injection was 16.6 weeks) and were followed for 52 weeks from the initial injection. Results showed that both injections were associated with similar improvements in OA knee pain. With regard to safety, higher rates of mild to moderate arthralgia were observed after the second dose (16%) than after the first dose (6%). The data from this study were insufficient to fully characterize the safety of repeat administration of Zilretta.

Commenting on the updates, Michael Clayman, MD, President and Chief Executive Officer of Flexion, said, “We are very pleased with the new product label as it achieves our primary goal of removing unclear language pertaining to repeat administration, which we believe was potentially confusing to patients, physicians and payers alike.”

For more information visit zilrettalabel.com.