Kolon Life Science said it would conduct a long-term follow-up study on over 3,700 patients who were treated with osteoarthritis gene therapy Invossa for 15 years.
The regulator recently suspended the sales of Invossa after the company revealed that the cell ingredient of the second fluid of the drug was kidney-derived GP2-293 cells, not the authorized cartilage-derived cells.
The so-called 293 cells are abnormal cells transduced for limitless proliferation, just like cancerous cells. In a laboratory, 293 cells are used for massive production of viruses. Using 293 cells as a treatment was unprecedented which raised safety concerns for Invossa, although the company said radiations blocked tumorigenicity.
The U.S. National Center for Biotechnology Information (NCBI) said in a paper that 293 cells, which rapidly change the expression of cancer-related genes, cause chromosomal instability, and exacerbates tumorigenicity. Earlier, the Ministry of Food and Drug Safety (MFDS) demanded that Kolon conduct special monitoring and long-term follow-up on all of the patients who received Invossa injections for safety.
Kolon expected that the follow-up would cost more than 80 billion won ($66.9 million). In a public disclosure on Wednesday, the company said it set aside 62.1 billion won for the follow-up study.
The company has been observing 163 patients who participated in a clinical trial on Invossa before the drug approval. The company decided to do the same on other 3,700 patients additionally.
The long-term follow-up will include a general blood test, serologic test, vital signs, TGF-b1 enzyme-linked immunosorbent assay (ELISA), TGF-b1 polymerase chain reaction (PCR), replication competent retroviruses (RCR) test, X-ray, and genetic test. For further details, the company will consult with the MFDS.
A hospital that injected Invossa to a patient should register the patient’s information with the “Invossa-K Injection Long-term Follow-up Patient Registration System” of the Korea Institute of Drug Safety and Risk Management. Patients can be informed about the registration process by visiting the hospital that prescribed Invossa or making a phone call. They can also contact Kolon Life Science’s call center at 02-3688-4020.
“Through 15 years of continuous monitoring, we will concentrate our capacity to relieve concerns of Invossa-injected patients and their families,” Kolon Life Science CEO Lee Woo-sok said.