The effectiveness and safety were assessed through to week 52.
Results
Through week 24, TLC599 was numerically superior to placebo with regard to WOMAC pain at all measured study time points and statistically superior at week 12 (P<0.05). For average daily pain, TLC599 was numerically and statistically better than placebo at all time points after the first injection (P<0.05).
When compared with dexamethasone sodium phosphate at week 12, TLC599 was superior in reducing the average daily pain after the first injection (P<0.05). After the second injection, when 203 patients received TLC599 and 94 received placebo, TLC599 proved numerically superior to placebo for reducing the average daily pain of patients at all time points from baseline to week 52.
TLC599 was also statistically superior to placebo through week 34.
The safety data showed the adverse effects among the three treatment groups were comparable, and TLC599 was generally well tolerated. After the first and second injections in patients who received TLC599, the morning serum cortisol level had a transient decrease. This result normalized by weeks 2 and 26. No patients showed signs or symptoms of adrenal insufficiency.
Conclusion
This phase 3 study demonstrated that patients with knee OA who received TLC599 experienced a greater reduction in average daily pain and WOMAC pain scores than those who received placebo at week 24 and week 52 following a second injection. Minimal side effects were seen after the two injections.
These results provide additional information about benefits of repeated corticosteroid injections for patients with knee OA. Additionally, they suggest that managing knee OA pain with TLC599 may provide a prolonged benefit and offer an alternative to corticosteroids in a nonsurgical treatment.
Michele B. Kaufman, PharmD, BCGP, is a freelance medical writer based in New York City and a pharmacist at New York Presbyterian Lower Manhattan Hospital.
References
- Spencer-Green G, Hunter D, Schnitzer T, et al. A phase 3 study of repeat injection of TLC599 in osteoarthritis of the knee: Benefits to 52 weeks [abstract L19]. Arthritis Rheumatol. 2023 Oct;75 (suppl 9).
- About osteoarthritis. Arthritis Foundation. 2024.
- Phase 2a, randomized, double blinded, placebo controlled, dose finding study for TLC599 in OA patients (NCT03005873). ClincalTrials.org. 19 Sep 2018.
