RCGD423, a small molecule gp130 modulator, prevents articular cartilage degeneration and promotes repair.

The ability of RCGD 423 to inhibit hypertrophy in human cells was confirmed by assessing RUNX2 and COL 10 levels in healthy and osteoarthritic articular chondrocytes following incubation with the compound. RCGD 423 elicited a unique signaling profile, driving strong increases in pSTAT3 and MYC levels without activating AKT or NF-κB, resulting in a signaling milieu downstream of gp130 similar to actively proliferating and anabolic fetal chondrocytes.

Operated animals would receive an intra-articular injection of 4 μg RCGD 423 loaded onto microspheres at the time of surgery and another 3weeks later. In RCGD 423-treated animals, there was little to no cartilage degradation, structural damage or generation of osteophytes. Control animals showed increased levels of cartilage-degrading proteins and markers of hypertrophy, while these were mostly absent in RCGD 423-treated rats.