Flexion Therapeutics Inc. (NASDAQ: FLXN) shares popped on Friday after the company announced that the U.S. Food and Drug Administration (FDA) has approved a supplemental New Drug Application (sNDA) to update the product label for Zilretta for the treatment of osteoarthritis (OA) knee pain.
One of the key elements of the label update is the removal of language that stated Zilretta was “not intended for repeat administration.” The updated label states that the “efficacy and safety of repeat administration of Zilretta have not been demonstrated.”
The label update will include a study description and safety data from the single-arm, open-label Phase 3 repeat administration trial. It also will remove a misleading statement describing a single secondary exploratory endpoint in the original Phase 3 pivotal trial that compared Zilretta to immediate-release triamcinolone acetonide crystalline suspension.
Michael Clayman, M.D., president and CEO of Flexion, commented:
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. In addition, we are gratified by the inclusion of safety data from our repeat administration trial and the removal of the inappropriate comparator statement. We believe the updated label supports our goal of seeing Zilretta become the leading intra-articular therapy for managing OA knee pain.
In 2016, Zilretta was approved by the FDA as the first and only extended-release intra-articular therapy for patients confronting OA-related knee pain. The pivotal Phase 3 trial on which the approval of Zilretta was based demonstrated that Zilretta significantly reduced knee pain for 12 weeks, with some people experiencing pain relief through week 16.
Shares of Flexion closed Thursday at $19.17, in a 52-week range of $8.76 to $21.39. The consensus price target is $27.10. Following the announcement, the stock was up about 19% at $22.77 in early trading indications Friday.