The agency cited the company for failing to submit a supplement for a change in the production process and quality controls. Specifically, Merck prepared production cell culture from a pre-existing production cell culture instead of from the master cell culture, a change that required the company to file a prior-approval supplement. The company also instituted a re-isolation procedure for selecting cells for use in production of asparaginase intermediate without characterizing the new isolate prior to use in production.
FDA cited these violations in a Form 483 following a February inspection of the company’s plant in Riverside, Pennsylvania. FDA issued the warning letter because it found the company’s responses to the Form 483 to be inadequate.
