Safety and Systemic Exposure of Triamcinolone Acetonide Following Ultrasound-Guided Intra-Articular Injection of Triamcinolone Extended-Release or Standard Triamcinolone Acetonide in Patients with Shoulder Osteoarthritis: An Open-Label, Randomized Study

BACKGROUND AND OBJECTIVES: Osteoarthritis (OA) is a major public health burden. While knee and hip joints are most commonly affected, the glenohumoral (shoulder) joint is also frequently involved. We evaluated the pharmacokinetics and safety/tolerability of triamcinolone acetonide extended-release (TA-ER) and triamcinolone acetonide crystalline suspension (TAcs) in patients with shoulder OA. METHODS: In this phase 2, randomized, open-label, single-dose study (NCT03382262), adults with moderately-to-severely symptomatic shoulder OA for ≥ 6 months randomly received a single ultrasound-guided intra-articular (IA) injection of TA-ER 32 mg or TAcs 40 mg. Safety was evaluated throughout 12 weeks post-injection; blood samples for pharmacokinetic evaluations were collected pre-injection and through Day 85 post-injection. RESULTS: Among 25 randomized patients, 12 received TA-ER and 13 received TAcs. Most patients were female (60%), and all had moderate (72%) or severe (28%) shoulder OA. Adverse events (AEs) were reported by four (33%) patients following TA-ER and three (23%) following TAcs injection. No AE was serious or led to study discontinuation. Systemic exposure following TAcs was approximately 1.5-fold higher than that following TA-ER injection (geometric mean [GM] AUC(0–last) 873,543 vs 557,602 h × pg/mL). GM C(max) was also higher in TAcs- than TA-ER-treated patients (2034 vs 1283 pg/mL). Bioequivalence testing confirmed lower systemic TA exposure following TA-ER than TAcs IA injection. CONCLUSION: These pharmacokinetic data confirm protracted release of TA from TA-ER following IA injection in patients with shoulder OA. Lower peak and systemic TA exposure following TA-ER suggests TA-ER could potentially confer an improved systemic safety profile over TAcs. TRIAL REGISTRATION NUMBER: NCT03382262 (December 22, 2017 retrospectively registered).