A Randomized, Open-Label, Single-Dose Study to Assess Safety and Systemic Exposure of Triamcinolone Acetonide Extended-Release in Patients With Hip Osteoarthritis

Introduction Intra-articular (IA) corticosteroids, including triamcinolone acetonide (TA), are a recommended treatment for hip osteoarthritis. We compared the safety and systemic exposure of TA extended-release (TA-ER) versus TA crystalline suspension (TAcs) in patients with hip osteoarthritis. Methods In this phase 2, randomized, multicenter, open-label, single-dose study (NCT03382262), patients with hip osteoarthritis were randomly assigned 1:1 to receive single IA injections of TA-ER 32 mg or TAcs 40 mg. Safety assessments included treatment-emergent adverse events (TEAEs). Blood samples were collected for pharmacokinetic (PK) analysis up to day 85. PK parameters included area under the concentration–time curve, total body drug clearance, maximum concentration ( C max ), mean residence time, half-life, and time to maximum concentration. Results Of 30 patients (TA-ER: n = 15; TAcs: n = 15) randomized and included in the Safety Population, 25 patients were evaluated in the PK Population. TEAEs were reported in four of 15 (26.7%) patients who received TA-ER and in seven of 15 (46.7%) patients who received TAcs. The most common TEAEs included arthralgia and headache. All TEAEs were of grade 1 or 2 in severity. TA-ER produced substantially lower peak plasma TA concentrations compared with TAcs ( C max geometric mean: 890.4 vs. 5549.4 pg/ml), and these were less variable with TA-ER versus TAcs. Similarly, overall TA systemic exposure was substantially lower for TA-ER versus TAcs, with gradual elimination from systemic circulation through day 85. Conclusions Following a single IA injection in the hip, TA-ER was generally well tolerated, with a safety profile comparable to that of TAcs. Systemic TA exposure was markedly lower in TA-ER-treated patients, consistent with the PK profile observed in knee osteoarthritis. Clinicaltrials.gov identifier: NCT03382262.