[EXCERPT]. Regarding a letter by Erika Lietzan (1) addressing our article on regulating biotechnology drugs in Colombia (2), we offer the following response. As Lietzan states, it is true that there is a global consensus on the two regulatory pathways to obtaining market authorization for biological medicines the full dossier pathway for pioneer products and an abbreviated pathway for competitors (biosimilars), called the “comparability pathway” in Colombia. The scientific principles of the abbreviated pathway are clearly stated in our article, referencing the WHO Guidelines on Evaluation of Similar Biotherapeutic Products (3), which underscores the importance of demonstrating a high similarity of physicochemical and functional characteristics between the biocompetitor and the reference product...