GQ-201 is a gene transfer vector for the treatment of osteoarthritis in horses. After direct injection into the affected joint, GQ-201 enters the joint cells and turns them into factories for production of a therapeutic protein. The protein diffuses into the joint fluid from where it acts on the joint cells. It inhibits inflammation and stops the cartilage degeneration, which is the underlying process of osteoarthritis.

Due to the gene therapy approach, joint cells containing GQ-201 are expected to produce the therapeutic protein over a long period of time.

Preclinical studies have shown that GQ-201 enters joint cells efficiently and can express proteins for more than one year. Moreover, the efficacy was demonstrated in a mouse osteoarthritis model. In horses with induced osteoarthritis, GQ-201 was shown to be safe and produced the target protein at therapeutic concentrations. Lameness of joints treated with GQ-201 improved markedly better and faster compared with placebo. Therefore, GQ-201 has demonstrated the proof of concept that it treats osteoarthritis in horses efficiently.