Kolon Life Science said that U.S. orthopedic surgeons had published a research paper that showed the mislabeled cell ingredient of Invossa's second fluid -- kidney-derived cells (GP2-293 cells) -- has no impact on the quality, safety, and efficacy of the treatment.
The study came after the Seoul Administrative Court rejected a petition made by Kolon Life Science to suspend the government's decision to revoke the sales approval of Invossa-K on Aug. 14.
According to the Korean company, Dr. Javad Parvizi, director of clinical research at Rothman Orthopedic Institute of Philadelphia and Dr. Michael Albert Mont, a former associate professor of orthopedic surgery at Johns Hopkins Hospital, published the paper titled "The Safety and Efficacy of a Novel Cell-Based Gene Therapy for Knee Osteoarthritis," in the Surgical Technology International, a U.S. orthopedic journal.
The paper stated Invossa-K has caused no lethal side effects and proved its efficacy through years of clinical trials on knee osteoarthritis patients.
"Due to a misidentification error, there have been concerns that this cell-based gene therapy is based on a different cell than the one that was initially approved," the report said. "However, its safety profile has been demonstrated by over 10 years of data revealing no evidence of tumorigenicity or other long-term safety concerns."
In all studies to date, there have been no treatment-related serious adverse events, the abstract added.
The report did disclose, however, that Professors Parvizi and Mont had participated in Invossa's clinical trials in the U.S. until Kolon Life Science suspended clinical trials for the drug in April.
"Two of the authors participated in the U.S. clinical trial for Invossa, but there were two other researchers who were unrelated," the company said. "The report is meaningful as it is the first paper published based on scientific evidence after the current incident."