Intraarticular Trans-Capsaicin Effective in Knee OA Save

A novel study has shown that intraarticular therapy with high‐purity synthetic trans‐capsaicin (CNTX‐4975) for chronic knee osteoarthritis (KOA) was associated with significant relief of knee pain.

The TRIUMPH study was a double‐blind, phase 2 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 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 KOA 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).