To the Editor:—
Dr. Brown's interpretation of our regulations (203: 857, 1962) states that the investigator must "retain all records until two years after his study ends or after the New Drug Application (NDA) is approved." The regulation reads "... or if the application is not approved, until two years after the investigation is discontinued." This means the investigator must retain his records until two years after the NDA is approved or until two years after he has been notified by the sponsor that the study of the drug has been officially discontinued. For example, if an investigator had completed his study on an investigational drug in 1965 and was told by the sponsor in 1967 that the investigation was officially discontinued (the Food and Drug Administration official notification), the investigator must retain his records at least until 1969.