A Post-Authorization Efficacy Study (PAES) is a study performed after the marketing authorization and aiming principally to further evaluate the efficacy of the medicinal product.

Post-Authorization Efficacy Study

PAES refers to studies performed after marketing authorization when concerns relating to some aspects of the efficacy of the product are identified, or when the understanding of the disease or the clinical methodology indicate that previous efficacy evaluations might have to be modified significantly.

PAES in the European Union

In the EU, a PAES evaluation may be financed by a MAH voluntarily. However, the EMA guideline on good pharmacovigilance practices mentions the possibility to impose to the MAH the conduct of PAESs. The intention is to complement efficacy data that are available at the time of the initial authorization. A PAES can be imposed during evaluation of initial MAA or during PA phase whenever there are doubts on efficacy.