Phase 4 post-licensing

Phase IV. post-licensing studies in the target population, with widening of entry criteria to broaden experience in clinical practice study objectives are typically surveillance for safety or further comparisons with other therapies. The results of such trials are more likely to be used for marketing purposes than in support of applications to regulatory authorities. 

This is a post-marketing study, to establish the long-term safety of a drug, especially when a biopharmaceutical is intended for prolonged use. If unexpected adverse effects are observed the product can be withdrawn from the market. Some Phase III licenses are granted with the condition that an additional study phase should follow according to a predefined plan. 

The overall performance assessment for the rq)ository system (overall geological situation, mine, waste package) must prove (operational phase) and give reasonable assurance (post operational phase) that the quantitative safety criteria are met. The long term safety assessment consists of the identification and description of potential pathways of radionuclide release, migration and exposure. The establishment of waste acceptance requirements based on the conq>liance of the performance assessment results with the safety criteria is the last step before a disposal facility can be licensed and operated. 

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