Yale researchers found in preclinical testing that lacosamide, an epilepsy medication, reduced osteoarthritis-related pain and helped reverse cartilage damage. The findings were strongest when the drug was delivered directly into the affected joint through a specialized hydrogel.
The work focused on Nav1. 7, a sodium channel that helps transmit electrical signals. Researchers found that the protein becomes more active in osteoarthritis, where it contributes both to pain signaling and to cartilage breakdown by disrupting the activity of chondrocytes, the cells that maintain cartilage.
Lacosamide blocked Nav1. 7 and produced strong biological effects at relatively low concentrations. The drug also stimulated release of HSP70 and midkine, proteins involved in cellular stress responses, tissue repair, inflammation regulation and protection against joint degeneration.
Oral lacosamide worked in preclinical tests but circulated throughout the body, creating the possibility of unwanted effects elsewhere. To concentrate the drug in the joint, the team developed a Collagen II hydrogel that stays liquid in a cool syringe and becomes a jelly-like material at body temperature, helping it remain in the knee after injection instead of being cleared within hours.
Study investigator Liu described Nav1. 7 as a target that could affect both pain and structural joint deterioration. Lacosamide has also been tested in humans for certain nerve-related pain conditions linked to Nav1. 7 mutations, but the osteoarthritis findings remain preclinical.