Introduction: Alemtuzumab is a new generation monoclonal antibody with anti-CD52 action and with specific indication for relapsing-remitting multiple sclerosis. In recent years, however, "off-label" applications in the immunological field have begun, such as immunosuppression in transplants or the treatment of other dysimmune diseases. The purpose of this article is, starting from its characteristics, to describe these uses and the tolerability profile. Materials and methods: A computerized search was carried out for the articles inserted through the use of international databases such as pubmed, scopus, researchgate, google scholar, selecting articles about alemtuzumab with particular regard to pharmacovigilance and new off-label applications. The research was carried out by selecting recent articles, obviously also including those relating to authorized uses. We also use the AIFA site and some books for the chapter on pharmacovigilance together with the "codifa" site to evaluate the technical data sheet. Discussion and Conclusion: Alemtuzumab is an interesting drug, very potent and usable for both inducing and maintaining remission from highly active forms of multiple sclerosis. However, induced immuno-reconstitution has prompted researchers to test its use both in the transplant field, especially for the immunosuppression induction regimen in the immediate post-surgical period, and for immuno-manipulation in the management of autoimmune diseases such as some rheumatic forms. refractory to conventional treatments. However, it must be said that safety is not always favorable, as it is associated with two important risks; severe opportunistic infections (including PML) and induction of secondary autoimmunity, particularly on the thyroid gland.