Are there biosimilar orphan drugs for Gaucher disease? An overview in Mexico

Enzyme replacement therapy (ERT) is the first-line treatment for Gaucher disease (GD). The ERT Cerezyme (imiglucerase) was approved by the US Food and Drug Administration (FDA) in 1994; however, its patents have expired allowing the development of non-originator biological drugs. The Group of Medical Specialists on Gaucher disease in Mexico claims there is a 'regulatory gap' in the definition of biosimilar orphan drugs which should be resolved before these drugs are approved and marketed. In Mexico, Asbroder (imiglucerase; Abcertin in other countries) has been approved for the treatment of GD, but it does not meet the exact definition of a biosimilar described by the World Health Organization (WHO) and other international guidelines. However, it was recognized as an orphan drug for GD and approved by the medicines regulatory authority in Mexico with the same international non-proprietary name (imiglucerase), in order to increase national access to treatment. This regulatory practice opens up a debate surrounding the relationship between international guidelines, clinical medicine, scientific evidence, bioethical considerations, public health institutions, and local laws. The aim of this paper is to establish whether there are biosimilars of imiglucerase as a therapeutic option. Moreover, it describes the regulatory setting of non-originator biological drugs in orphan diseases based on the approval of the non-originator imiglucerase in Mexico.