An extended-release formulation of triamcinolone acetonide gives a clinically relevant improvement in pain relief in patients with knee OA compared to the immediate release formulation, a phase II trial finds.

The double blind dose ranging study randomised 228 patients with moderate to severe knee OA to a single intra-articular injection of 10mg, 40mg, or 60 mg extended release triamcinolone acetonide (FX006) or 40 mg of immediate-release triamcinolone acetonide.

Results showed a 40mg dose of FX006 provided a clinically meaningful improvement in analgesia compared to immediate-release triamcinolone acetonide while substantially reducing systemic exposure.

From five weeks to ten weeks FX006 was significantly superior to immediate-release triamcinolone acetonide (p < 0.05 at each time point), with a mean pain reduction relative to immediate-release triamcinolone acetonide of 20.9 on the 11-point Numeric Rating Scale, the researchers reported.

“The extended residency of triamcinolone acetonide in the joint with the 40-mg dose of FX006 not only prolonged but also amplified the analgesic effect, “ they wrote.

“This constitutes a meaningful clinical improvement relative to immediate-release triamcinolone acetonide as evidenced by significant improvement in both the OMERACT-OARSI and the >20%, >30%, and >50% improvement responder analyses at eight weeks.”

The 60-mg dose did not provide additional improvement relative to the 40-mg dose, the researchers including David Hunter reported in the Journal of Bone and Joint Surgery.

“The sustained local residence of triamcinolone acetonide provided by FX006 may be of utility in the treatment of other musculoskeletal disorders and dermatologic conditions,” the researchers added.