IND stands for Investigational New Drugs.
Exploratory IND studies usually involve very limited human exposure and have no therapeutic or diagnostic intent.
These studies can serve a number of useful goals.
For example, an exploratory IND study can help sponsors
- Determine whether a mechanism of action defined in experimental systems can also be observed in humans (e.g., a binding property or inhibition of an enzyme)
- Provide important information on pharmacokinetics (PK)
- Select the most promising lead product from a group of candidates designed to interact with a particular therapeutic target in humans, based on PK or pharmacodynamic (PD) properties.
Difference Between Traditional IND vs. Exploratory IND
Preclinical testing strategy for traditional and exploratory INDs. Studies generally conducted under a traditional IND include pharmacokinetic and pharmacology studies to evaluate different dosing schedules or routes of administration, such as tests of animal absorption, distribution, metabolism, and excretion, analytic assays, and drug formulation testing. Both INDs require single-dose (acute) toxicology studies in two mammalian species to determine toxic and safe doses.
For the exploratory IND, these studies may have a single-dose or dose-escalation design; subsequent repeat-dose toxicology studies in oncology reflect the proposed clinical schedule. For the traditional IND, two mammalian species are tested for cumulative toxicities arising from repeat-dosing that reflects the clinical route and schedule, including full histopathology and clinical sign evaluation; other preclinical studies to assess drug or vehicle activity and safety and support the IND can be conducted as needed. Genetic toxicity testing of oncology agents is not necessary until prior to phase II testing. Full genetic toxicity evaluation includes in vitro bacterial reverse mutagenicity tests, in vitro mammalian chromosome damage tests, and in vivo chromosomal damage tests (i.e., in vivo rodent micronucleus assay).