Relevance of distinctions and parallels between the US and EU guidelines for determination of comparative effectiveness and safety of the orally inhaled drug products

Approval of drug products for market registration warrants, among other data, evidence to support their safety and effectiveness in the target populations. The extent of investigations to provide the supporting evidence varies between the new innovator products and their follow-on versions generally referred to as Generic Drugs Products in the United States and Hybrids in the Europe. The new drug applications entail large data sets encompassing both nonclinical and clinical product developments. Safety and effectiveness in man is studied in sequentially phased clinical trials, including post marketing evaluations (Where applicable). However, for the generic/hybrid products the safety and effectiveness are established through determination of bioequivalence in head-to-head comparison between the originator and the follow-ons. Methods for documentation of bioequivalence for drug products that reach target site(s) through systemic circulation are aligned worldwide. However, establishing bioequivalence of orally inhaled drug products is complex as drug delivery to the local site(s) of action is independent of the systemic circulation. Documentation of bioequivalence gets further complicated due to the Drug-Device combination nature of these products. The guidelines for establishment of BE of locally acting orally inhaled drugs products vary among certain geographies. This article examines the scientific underpinning of distinctions and similarities between the US and EU guidelines.