The Ministry of Food and Drug Safety inspected six gene therapy companies as a follow-up measure to the Invossa issue, a wire report said Thursday.

Invossa, a gene therapy for joint inflammation treatment by Kolon Life Science, was stripped of its sales approval in May this year after the company belatedly reported a mislabeling of the key cell used in the drug.

Invossa obtained the MFDS approval in July 2017 and started commercial sale in November of the same year.

While attempting to make inroads into the US market, KLS said it realized that what the company had thought was the source cell of Invossa had in fact been kidney-derived cell, not the cartilage-derived cell indicated in its documents earlier submitted for approval in Korea.

This mix-up had a devastating effect on the company, as the kidney-derived 293 cell in question was suspected to have potentially cancerous properties.

KLS countered the suspicion saying that the radiation treatment of the 293 cell made it safe.

The company said it will run a 15-year free medical check-up for patients who have taken the Invossa shot while trying to restart the phase 3 clinical trials for the drug in the US.

The US Food and Drug Administration recommended KLS replace the kidney-derived cell to cartilage-derived cell.

Kolon TissueGene, the US-based affiliate responsible for the research and development of Invossa, was tentatively delisted from the Kosdaq bourse in August.

Kolon’s demise has prompted the Drug Ministry to run a good manufacturing practice inspection on the 10 other gene therapy companies in Korea.

GC Green Cross Cell, Medipost, Tego Science and Corestem were among the six that were inspected in late August and early September.

Based on the inspection results, follow-up measures will take place this month at the earliest.

By Lim Jeong-yeo (kaylalim@heraldcorp.com)