Xeomin®:: Perspectives of a novel therapeutic botulinum toxin preparation

Botulinumtoxin (BT) for therapeutic purposes is available as BOTOX (R), Dysport (R), and NeuroBloc (R)/Myobloc (R). In July 2005 Xeomin (R) was introduced in Germany as a new therapeutic BT type A-preparation. Xeomin (R) is distributed in packages of 1, 2 or 3 vials each containing 100 mouse units of a vacuum dried powder. Before reconstitution with normal saline it has a shelf life at room temperature of 36 months. Compared to conventional BT preparations Xeomin (R) excels with an improved specific biological activity. This should reduce its antigenicity and the risk of BT antibody formation. With these properties Xeomin (R) could improve BT therapy and potentially allow high dose applications, injection series with reduced interinjection intervals and booster injections for improved dose finding which are all currently not approved because of fear of BT antibody formation. Whilst conventional BT preparations consist of botulinum neurotoxin-complexing protein dimers of 600 kD or 900 kD Xeomin (R) consists of monomeric botulinum neurotoxin of 150 kD. Whether this transforms into an immunological advantage is unclear. Current clinical experience suggests that Xeomin (R) and BOTOX (R) are identical with respect to the onset and duration of their therapeutic effects and to their adverse effect profiles. This allows BT therapy conversion between BOTOX (R) and Xeomin (R) without changing the individualised injection scheme. Animal experiments and clinical studies are necessary to evaluate the expected reduced antigenicity of Xeomin (R) and the role of the complexing proteins.