Biological sample disposition [Bioanalytics]
❝ If sample discarded, then what will be the regulatory issue?
As far as I know: none. I am not aware of any requirement in any of the main BE guidelines (EU, USA, WHO...) requiring the plasma samples to be kept for any period of time once the trial is completed.
The main possible issue is if the re-analysis of the samples is needed once the list of questions is received from the authorities (if they want another analyte, or if problems are identified with the bioanalytical method used). But then you won't have sufficient long-term stability data anyway.
As Helmut says in his answer: make sure the retention period is specified in the contract.