GQ-303 is a helper-dependent adenoviral gene therapy vector expressing proteoglycan 4 (a.k.a. lubricin), which is being developed for treatment of osteoarthritis. After intraarticular injection into the affected joint, GQ-303 enters the joint cells and turns them into factories for production of the therapeutic protein proteoglycan 4. Proteoglycan 4 has a biomechanical effect (improving lubrication) and inhibits molecular pathways that promote disease progression in osteoarthritis. GQ-303 has demonstrated symptomatic and disease-modifying efficacy in several osteoarthritis animal models. GQ-303 is currently at preclinical stage and anticipated to enter clinical trials soon.

GeneQuine is initially targeting knee osteoarthritis patients with GQ-303 with the potential to expand to other osteoarthritis types later.