Breakthrough Injection Could Reverse Cartilage Loss and Stop Osteoarthritis

Scientists have developed an injection that helps animal cells regrow cartilage, offering hope for preventing osteoarthritis. The treatment targets a protein linked to ageing, which weakens muscle and joint repair over time. Early tests in mice show promising results, with thicker cartilage and reduced arthritis risk after injury.

The injection works by blocking a protein called 15-PGDH, which rises with age and harms muscle stem cells. In mice, just two doses a week for four weeks cut the chances of osteoarthritis developing after a joint injury. The drug also thickened cartilage and encouraged cells to produce new, functional tissue.

Tests in older mice revealed another benefit: blocking 15-PGDH boosted muscle mass and endurance. Surprisingly, the same effect shrank muscles in younger, healthy mice. Meanwhile, Phase 1 trials of an oral version of the inhibitor have already shown success in treating muscle weakness in humans.

Beyond injections, oral 15-PGDH inhibitors are also under study. Standigm and Samsung Bioepis's SW033291, along with Pelage Pharmaceuticals' PP405, have reached Phase 1 and Phase 2a trials for hair loss and kidney injury. Data from 2025 confirmed PP405's safety and ability to raise prostaglandin levels in healthy volunteers, while later trials for hair regrowth reported strong results with no serious side effects.

Further human trials are now planned to explore how well the injection could regenerate cartilage. If successful, the treatment might one day reduce the need for joint replacement surgeries.

The injection could transform how osteoarthritis is treated, particularly in older adults or those recovering from injuries. With clinical trials expanding, researchers aim to confirm whether the same cartilage-regrowing effects seen in mice will apply to humans. The findings may also open doors for broader uses of 15-PGDH inhibitors in age-related conditions.