A novel study has shown that intra-articular therapy with high‐purity synthetic trans‐capsaicin (CNTX‐4975) was associated with significant relief of knee pain in patients with chronic knee osteoarthritis (OA).
The TRIUMPH study was a double‐blind, phase II study in adults (45–80 years) with stable knee osteoarthritis. Patients were given an intra‐articular injection of placebo, CNTX‐4975 0.5 mg, or CNTX‐4975 1.0 mg. The primary efficacy endpoint was area under the curve (AUC) for change in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain with walking scores at week 12.
A total of 172 subjects were enrolled and at week 12, greater decreases in WOMAC pain scores were observed with CNTX‐4975 versus placebo.
- CNTX-4975 0.5 mg: LSMD −0.79, P=0.0740
- CNTX-4975 1.0 mg: LSMD −1.6, P<0.0001
- Efficacy continued till week 24 in the 1.0 mg group (LSMD −1.4, P=0.0002)
Adverse events were similar in the placebo and 1.0‐mg groups.
Knee pain from knee OA may be effectively and safely managed with this new investigational compound, CNTX‐4975, and is thought to be mediated by sustained desensitization of nociceptors (pain sensory fibers).
Jack Cush, MD, is the director of clinical rheumatology at the Baylor Research Institute and a professor of medicine and rheumatology at Baylor University Medical Center in Dallas. He is the executive editor of RheumNow.com. A version of this article first appeared on RheumNow, a news, information and commentary site dedicated to the field of rheumatology. Register to receive their free rheumatology newsletter.
Primary Source
Arthritis & Rheumatology
Source Reference: Stevens RM, et al "Randomized, Double‐Blind, Placebo‐Controlled Trial of Intra‐articular CNTX‐4975 (trans‐capsaicin) for Pain Associated With Osteoarthritis of the Knee" Arthr Rheumatol 2019; DOI: 10.1002/art.40894.