**1. Introduction**

Biological drugs have overturned the classic concept of medicine and pharmacology. They are now one of the cornerstones of modern medicine and the so-called "targeted therapy" or "personalized therapy," which acts specifically on a given target. Biological drugs are henceforth referred to as "biologics" in this work. Biologics include various products, such as hormones and enzymes, blood products, and immunological drugs (serums, vaccines, immunoglobulins, allergens, and monoclonal antibodies) [1].

These therapies have drastically improved the prognosis of several severe and life-threatening diseases, such as cancer, diabetes, and autoimmune diseases (e.g., rheumatoid arthritis, Crohn's disease, multiple sclerosis, and severe psoriasis) [2, 3].

Biologics are very different from "conventional drugs" in origin, structural complexity and variability, manufacturing process, side effects (immunogenicity), and regulatory aspects. This makes the pharmacovigilance of biologics particularly complex.

It should also be emphasized that a huge commitment of resources burdens therapies derived from biotechnologies and this, as repeatedly stressed by the various regulatory agencies, poses a significant problem in terms of economic sustainability at the global level. "Biosimilars", which are similar to original biologics that are no longer subject to patent protection, and can be marketed at lower prices than actual products, fit into this context, further complicating the already tricky pharmacovigilance for biologics.
