The FDA has proposed a guidance for sponsors on what studies of marketed cancer drugs or biological products can be conducted without submitting an application for an investigational new drug (IND).
The proposal emphasizes that exemption from the IND requirement depends primarily on whether the investigation significantly increases risk associated with use of the product. Ordinarily, uses well above the recommended dose might be associated with increased risk. But because in oncology modifications of labeled dosing recommendations are common, oncology studies deviating from the approved labeling can be exempted, provided such changes are supported by the literature and generally known clinical experience.
Crawford, Jr LM. IND Submission Exemptions. JAMA. 2002;287(22):2936. doi:10.1001/jama.287.22.2936-JFD20006-2-1