- The Food and Drug Administration has issued a warning letter to biosimilars maker Celltrion Inc., flagging issues related to manufacturing processes at the company's production facility in Incheon, South Korea.
- The warning letter, which officially puts recipients on notice of significant GMP violations, follows a Form 483 sent to Celltrion earlier this year.
- Celltrion does not expect the warning letter to limit its ability to manufacture and supply Pfizer Inc. with Inflectra, a biosimilar copy of the blockbuster TNF-inhibitor Remicade.
Celltrion is one of a handful of drugmakers at the forefront of biosimilar development, having won major market approvals for copies of Remicade (infliximab) and Rituxan (rituximab).
Like its South Korean rival Samsung Bioepis Co. Ltd., Celltrion has invested in dedicated manufacturing facilities and can boast 140,000 liters of production capacity across its two active plants.
Last May, the FDA inspected Celltrion's site outside Incheon, listing twelve observations in a Form 483 released in September. Now, the FDA has formalized those potential violations into a warning letter. As the letter has not yet been disclosed by the FDA, it's not clear where the regulator's principal concerns lie.
Celltrion, for its part, doesn't appear too concerned.
"We are making progress addressing these concerns, and we are committed to working with the agency to fully resolve all outstanding issues with highest priority," the company said in a Feb. 1 statement.
Notably for Pfizer, Celltrion doesn't anticipate any restrictions on manufacturing Inflectra from that same Incheon site.
Inflectra launched in U.S. markets in November 2016 at a 15% discount to Johnson & Johnson's Remicade, but uptake has been slowed by payer hurdles. Pfizer alleges that J&J's contracting practices have illegally blocked competition from Inflectra.
Global sales of the biologic copycat totaled $419 million last year, with $118 million earned in the U.S. market.
Editor's note: A previous version of this article did not specify the year in which Inflectra was approved. It was November 2016.