Flexion Therapeutics Announces First Patient Treated in FX301 Phase 1b Trial for Management of Post-Operative Pain

• FX301 is a locally administered NaV1.7 inhibitor (funapide) formulated for extended release in a proprietary thermosensitive hydrogel
• Proof-of-concept trial will evaluate safety and tolerability of FX301 administered as a peripheral analgesic nerve block in patients undergoing bunionectomy; initial data anticipated later this year

BURLINGTON, Mass., March 31, 2021 (GLOBE NEWSWIRE) — Flexion Therapeutics, Inc. (Nasdaq:FLXN) today announced the treatment of the first patient in a Phase 1b proof-of-concept trial evaluating the safety and tolerability of FX301 administered as a single-dose, popliteal fossa block (a commonly used nerve block in foot and ankle-related surgeries) in patients undergoing bunionectomy.

“There are approximately seven million orthopedic surgical procedures performed in the United States each year, and with many of those patients using opioids after surgery, there is a substantial need for non-opioid post-operative pain management,” said Michael Clayman, M.D., President and Chief Executive Officer of Flexion. “FX301 has the potential to deliver extended pain relief while preserving motor function which we believe could provide improved patient comfort, reduce the need for opioids, allow for earlier ambulation and physical therapy, and enable patients to leave the facility or hospital sooner following surgery.”

The Phase 1b randomized, double-blind, placebo-controlled study will be conducted in two parts beginning with a single ascending dose portion which will investigate FX301 at low and high doses of funapide administered at two volumes in four cohorts of patients undergoing bunionectomy. A total of 48 patients (12 patients per cohort), will be randomized to receive either FX301 or placebo. A Safety Monitoring Committee will review data from each dose cohort before the study escalates into higher doses.

The data from the single ascending dose portion of the trial will be reviewed and a decision made regarding expanding a selected dose and volume cohort by another 36 patients. This would support broader understanding of the safety and efficacy in that cohort.

FX301 represents a potential first-in-class analgesic nerve block agent. In a validated preclinical model of post-operative pain, FX301 administered as a peripheral nerve block demonstrated analgesic effect beginning at 1 hour post-dosing compared to placebo and significantly greater analgesic effect compared to liposomal bupivacaine at 36 hours post-dosing. Data from the study also indicated that treatment with FX301 did not significantly affect total walking distance in animals at 2 and 24 hours post-injection, whereas animals treated with liposomal bupivacaine experienced a significant reduction in total walking distance at those time points. The company anticipates sharing data from the Phase 1b trial of FX301 in late 2021.

About FX301
FX301 is an investigational locally administered NaV1.7 inhibitor known as funapide, formulated for extended release in a thermosensitive hydrogel. The initial development of FX301 is intended to support administration as a peripheral analgesic nerve block for control of post-operative pain. Flexion believes FX301 has the potential to provide effective pain relief for at least three to five days while preserving motor function.

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 OA, 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; timing and plans with respect to the Phase 1b clinical trial of FX301; and the potential therapeutic and other benefits of FX301, 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 FX301; risks related to clinical trials, including potential delays, safety issues or negative results; 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.

Contacts:

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

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