Phase 2b trial of a novel extended-release microsphere formulation of triamcinolone acetonide for intra-articular injection in knee osteoarthritis.
FX006 is a novel, microsphere-based, extended-release formulation of triamcinolone acetonide (TA) for intra-articular injection designed to maintain TA joint concentration and provide prolonged analgesic benefits in patients with osteoarthritis (OA) of the knee. The aim of this study was to compare the analgesic benefits of two FX006 doses with saline-placebo injection.
In this Phase 2b study, participants with knee OA (Kellgren-Lawrence Grade 2-3) and average daily pain (ADP)-intensity ≥5 to ≤9 (0-10 Numeric Rating Scale) were randomized (1:1:1) and received single IA injections of FX006 32 mg (N=104) or 16 mg (N=102) or saline-placebo (N=100). The primary endpoint was least-squares-mean (LSM) change from baseline to Week 12 in weekly mean ADP-intensity scores for FX006 32 mg versus saline-placebo.
The primary endpoint was not met (FX006 32 mg versus saline-placebo LSM-change at Week 12: -3.1 versus -2.5; LSM-difference [95% confidence interval] of -0.58 [-1.22, 0.07]; P = 0.08). However, FX006 32 mg improvements were significant versus saline-placebo at Weeks 1-11 and Week 13. FX006 16 mg improvements were significant versus saline-placebo at Weeks 1-9. A dose-response was evident in duration of maximal analgesic effect (32 mg: 13 weeks versus 16 mg: 9 weeks), with FX006 32 mg providing increased therapeutic benefit relative to FX006 16 mg. All treatments were well-tolerated.
Although the primary endpoint was not met, FX006 demonstrated a prolonged reduction in symptoms with an evident dose response and a safety profile similar to that of saline-placebo.