FDA Removes Clinical Hold On Flexion's FX006 Phase Osteoarthritis 2b Trial

Flexion Therapeutics announced in a press release that the Food and Drug Administration (FDA) has lifted the clinical hold on the FX006 trial in patients with moderate to severe osteoarthritis (OA) pain. The hold was due to a single patient that developed septic arthritis in the knee. The FDA has indicated that Flexion complied with its requests, testing, and investigation of the adverse event. Flexion states that it intends to resume the trial immediately and to begin a Phase 3 trial in 2015.

Michael Clayman, M.D., Flexion President and CEO, said, "We are pleased to have been able to rapidly provide data to the FDA that allowed the agency to remove the clinical hold. Now we can continue to advance FX006, which has the potential to make a real difference for the many individuals who suffer from OA pain."

FDA Action

The FDA placed the clinical hold on FX006 on September 16, 2014, due to a patient with an infection in the injected knee joint. The FDA requested that the company determine whether FX006 was the source of the infection by recovering the drug vials and unused study drug vials to test for contamination. The FDA also asked that Flexion consider other infection sources as well, such as unsterile equipment or breaches in procedure.

The company complied with the FDA’s request and engaged a certified third-party sterility-testing firm, which found no contamination in used or unused vials. Flexion examined the other possibilities and consulted with the principal investigator, the study coordinator, and the healthcare professional that administered the injection to the infected patient. Flexion states it could find no evidence that sterility was compromised, citing the other 100 patients in the study that received FX006 with no infections.

Due to the atypical nature of the adverse event, on October 28, 2014, the principal investigator changed the initial diagnosis from septic arthritis to inflammatory arthritis. The company believes that the event was a false positive as no cases of septic arthritis developed in the 300 patients that have been treated with FX006 since human trials began.

Flexion’s FX006

FX006 is an intra-articular steroid with a sustained release action. In a Phase 2b trial, the agent showed clinically meaningful and significantly better pain relief compared to standard treatments. FX006 was designed to provide long-lasting pain relief while limiting system side effects. Flexion states that advantages include its anti-inflammatory properties, prolonged efficacy, and absence of steroidal side effects.