Pharmacokinetics
Safinamide is absorbed quickly and nearly completely from the gut and reaches highest blood plasma concentrations after 1.8 to 2.8 hours. There is no relevant first-pass metabolism; total bioavailability is 95%. The substance is bound to plasma proteins to 88–90%.The metabolism is not well understood. The principal step is mediated by amidases which have not been identified, and produces safinamide acid (NW-1153). Other relevant metabolites are O-debenzylated safinamide (NW-1199), the N-dealkylated amine which is then oxidized to a carboxylic acid (NW-1689), and the glucuronide of the latter. In tests with liver microsomes, dealkylation seemed to be mediated by CYP3A4, but other CYP enzymes appear to be involved as well. Safinamide acid binds to the organic anion transporter 3 (OAT3), but this has probably no clinical relevance. Safinamide itself transiently binds to ABCG2. No other transporter affinities have been found in preliminary studies.Safinamide is eliminated, mainly (>90%) in form of its metabolites, via the kidney, with an elimination half-life of 20 to 30 hours. Only 1.5% are found in the stool. History
The compound was originally discovered at Farmitalia-Carlo Erba, which was acquired by Pharmacia in 1993. In 1995, Pharmacia merged with Upjohn. Safinamide was first disclosed in 1998. In the course of a major restructuring in the same year, all rights for safinamide were transferred to the newly formed company Newron Pharmaceuticals, which developed the drug until it was sold to Merck KGaA in 2006.In 2007, a Phase III clinical trial was started, scheduled to run until 2011.
In October 2011 Merck, now Merck-Serono, announced that they would give all rights to develop the compound back to Newron because they wanted to prioritise other projects and had corrected their estimates for safinamides market potential downwards.The US Food and Drug Administration (FDA) refused to file Newrons application in 2014 on formal grounds. Newron re-applied in December 2014. In spring 2015, following a commercial agreement between Newron and the Italian pharmaceutical company Zambon, the European Medicines Agency (EMA) approved the drug. In the following years, the drug has been launched in several European countries. Safinamide is the first antiparkinson medication to be approved for ten years. Safinamide was approved by US FDA in March 2017 for people with Parkinsons taking levodopa/carbidopa during "off" episodes. Research
Potential additional uses might be restless legs syndrome (RLS) and epilepsy. Safinamide was being tested in Phase II trials in 2008, but no results are available. When used as an adjunct to parkinsonian medication, safinamide was found to be efficacious in reducing pain in PD. References
External links
"Safinamide". Drug Information Portal. U.S. National Library of Medicine. "Safinamide mesylate". Drug Information Portal. U.S. National Library of Medicine.