Invossa, gene therapy for osteoarthritis of the knee, has shown promising results in a domestic clinical trial, Kolon Life Science said Wednesday. The company is seeking a disease-modifying osteoarthritis drug (DMOAD) designation from the U.S. Food and Drug Administration for, through a global phase-3 trial.

The biotech firm said it presented Invossa’s efficacy, shown in the two-year observation study, at the annual meeting of the American Academy of Orthopaedic Surgeons (AAOS) in Louisiana, the U.S.

According to the results of the local trial, led by Seoul National University Hospital’s orthopedic surgery professor Lee Myung-chul, patients treated with Invossa had their functions and activities of knees improve three times more than the placebo group, 12 months after the injection. Their pain and osteoarthritis symptoms also decreased twice as much as the placebo group.

Invossa treatment was also effective 24 months after the injection, showing meaningful improvements in the International Knee Documentation Committee (IKDC) evaluation, Visual Analog Scale (VAS) score, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score.

“Invossa showed significant effects on pain relief and improvement of joint function compared to the placebo. At 12 months after treatment, patients injected with Invossa had the response rate at 84 percent of all patients, twice as high as that of the placebo group at 45 percent,” SNUH’s Lee said. “Long-term follow-up observations for more than two years have proven efficacy, suggesting that it may be a major treatment option for patients who had to relieve pain or rely on short-term conservative treatment temporarily.”

For Invossa to be recognized as DMOAD from the FDA, the treatment should prove the effectiveness of long-term structural improvements. The company has to prove that Invossa’s efficacy in long-term structural improvements can last for at least two years to obtain the FDA’s DMOAD status.

Also, a biomarker analysis, which can predict the diagnosis and progression of osteoarthritis, confirmed the effectiveness to reduce the progression of osteoarthritis. Therefore, Invossa may become a fundamental therapeutic agent with DMOAD label, the company said.

Invossa is a gene therapy that treats knee osteoarthritis by injecting chondrocytes derived from allograft and cells containing growth factor called TGF-β1. The treatment only needs a simple injection procedure without an incision of the knee.

The company is conducting a global phase-3 clinical trial on more than 1,000 patients under the Kellgren & Lawrence Grade 2 to 3.

The global trial will be able to produce statistically significant results in structural improvement, as the number of participating patients is much higher than that of the domestic one at 160, the company said.