TG-C, our lead product candidate developed for the treatment of knee osteoarthritis (KOA), has completed Phase II trials in the US. Safety and efficacy have not been established by any US agency.
TG-C has the potential to become the first cell-based gene therapy to treat KOA. Phase II clinical trials conducted in the US have demonstrated significant improvements in pain relief and joint function over a two-year period.
Kolon TissueGene has completed enrollment in its US Phase III clinical trials, which are being conducted under a Special Protocol Assessment (SPA) agreement with the US Food and Drug Administration (FDA). The trials are currently in the two-year follow-up period. The studies are designed to investigate TG-C’s efficacy in improving pain and function as co-primary endpoints, and impact on joint structure, longer duration of pain, and quality of life as secondary endpoints. Positive results could support a potential designation as a disease-modifying osteoarthritis (OA) drug.
With the continued growth of the OA market globally, there remains a critical need for advanced therapeutic options that can halt or slow disease progression. Current treatments temporarily alleviate pain and improve function but do not prevent structural deterioration.
Kolon TissueGene is committed to improving OA-related pain and knee function.
Figure 1. Demographic distribution of adults with OA according to the location of the affected joint.1
OA can broadly be divided into groups according to the location of the joint affected, with most people suffering from knee OA, followed by hand OA, other joints, and hip (Figure 1). Although TG-C is currently being developed to treat the knee OA application, as shown in Figure 1 there are still large populations of individuals affected by OA in other joints who may benefit from TG-C’s mechanism of action. TG-C has been tested in the US for safety and efficacy as an OA treatment of the knee through Phase II clinical trials. Phase III clinical trials in the US are currently in the two-year follow-up period. Additionally, TG-C-K has also completed Phase III clinical trials in South Korea.
1. Splete H. Osteoarthritis burden grows worldwide, Global Burden of Disease study finds. Medscape Rheumatology. March 2022. Available at: https://www.mdedge.com/rheumatology/article/252364/osteoarthritis/osteoarthritis-burden-grows-worldwide-global-burden. Accessed: July 2026.
Spinal discs are rubbery structures located between the vertebrae that act as shock absorbers for the spine. Common disorders affecting these discs include spinal disc herniation and nucleus pulposus herniation, both typically caused by degenerative changes. These conditions can manifest as early as the late teens and are increasingly observed in active individuals between their 20s and 40s.
In nonclinical studies, TG-C demonstrated the ability to delay disc degeneration and showed preliminary evidence of inducing regeneration in damaged discs. Based on these findings, Kolon TissueGene received clearance from the FDA for an Investigational New Drug application in December 2023. The Company plans to initiate a Phase I clinical trial in the US to evaluate TG-C in subjects with degenerative disc disease.
The meniscus is a crescent-shaped fibrocartilaginous structure, located on the medial and lateral sides of the knee joint. The meniscus protects the knee joint by alleviating the pressure on the knee and supporting the correct functioning of the knee. Meniscus damage in younger people is typically caused by sports injuries, while meniscus damage in elderly people is more often observed as a degenerative disorder. It is more common in women than men and is considered to be caused by pressure and stress accumulated from the individual’s daily routines.
If the meniscus damage is not treated on time, it often develops into a more serious disease such as degenerative arthritis. In clinical trials of TG-C, evidence of the improvement of meniscus injury was observed, which suggests the potential for meniscus treatment by TG-C.
In animal studies, TG-C has shown to be effective in treating rheumatoid arthritis (RA). RA is an autoimmune disorder in which the individual’s own immune cells attack the joints, resulting in inflammation and damage to the articular cartilage and bone matrix. RA commonly occurs in the fingers and wrist; it is particularly observed in the knuckles, which become swollen. Unlike OA, which occurs in elderly populations, RA is often observed in young adults. The differences between OA and RA are shown in the table below.
When TG-C was injected into an RA animal model of inflammation, preliminary results in reducing the inflammatory response were promising. These results indicate the possibility of using TG-C in the future as a treatment for RA.
| OA | RA | |
|---|---|---|
| Cause | Aging, overweight, repetitive movements | Disorder of immune system |
| Symptom | Uncomfortable walking, pain after movement | Pain and fever in the joints, pain after rest |
| Affected Joint | Large joints such as knee, back, and hip | Small joints such as finger, wrist, and toe |
| Age | Typically people over 50 | All ages |
OA is a common illness among companion animals. Based upon the results observed in nonclinical studies, TG-C has demonstrated efficacy in treating animal OA. It is anticipated that upon successful completion of the animal studies, TG-C will also be able to provide benefits to companion animals in alleviating their pain and slowing the progression of the disease.
