Company to host conference call tomorrow, September 18, 2014 at 9:00 a.m. ET to discuss the clinical hold

BURLINGTON, MA, USA I September 17, 2014 I Flexion Therapeutics, Inc. (FLXN) today announced that the United States Food and Drug Administration (FDA) informed the company yesterday that a clinical hold has been placed on patient enrollment and dosing in an ongoing Phase 2b clinical trial evaluating FX006 in patients with osteoarthritis (OA) of the knee. FX006 is a novel, non-opioid, sustained-release, intra-articular (IA) formulation of triamcinolone acetonide (TCA) targeting moderate-to-severe OA pain.

Flexion has not yet received written notice of its clinical hold from the FDA, but based on the verbal communication yesterday afternoon, the FDA indicated that the clinical hold is due to a single occurrence of an infection in the injected knee joint of a patient in the Phase 2b clinical trial.

“We will work closely with FDA to provide the agency with all appropriate information and data required to expedite their review and evaluation of this event,” said Michael Clayman, M.D., President and CEO of Flexion. “Once the FDA has completed its review, we can better assess the impact this clinical hold will have on our development program timeline for FX006.”

Conference Call

Flexion’s management team will host a conference call and webcast at 9:00 a.m. EDT tomorrow, September 18, 2014, to discuss the clinical hold. The dial-in number for the conference call is toll-free (855) 770-0022 for domestic participants and (908) 982-4677 for international participants. A live webcast of the conference call can also be accessed through the “Investors” tab on the Flexion Therapeutics website at www.flexiontherapeutics.com. A webcast replay will be available online after the call.

About Flexion Therapeutics

Flexion is a clinical-stage specialty pharmaceutical company focused on the development and commercialization of novel pain therapies. The company is currently advancing a portfolio of injectable drug candidates that have the potential to provide better and more persistent analgesia compared with existing therapy. The company’s lead program, FX006, is an intra-articular sustained release steroid in development for patients with moderate to severe OA pain. The company also has two additional product candidates, FX007, a locally administered TrkA receptor antagonist for post-operative pain, and FX005, an intra-articular, sustained-release p38 MAP kinase inhibitor for end-stage OA patients.

SOURCE: Flexion Therapeutics