The European Commission has granted marketing approval for BioMarin Pharmaceutical‘s 3,4-diaminopyridine (amifampridine phosphate), a new treatment for the rare autoimmune disease Lambert Eaton Myasthenic Syndrome (LEMS).

The drug is the first approved treatment for LEMS in the EU, a landmark which confers it orphan drug status and provides ten years of market exclusivity in Europe.

LEMS is a rare autoimmune disease with the primary symptoms of muscle weakness that is believed to affect around 2,000 to 5,000 patients in the EU and 1,200 to 3,100 patients in the US and can in respiratory cases, lead to death.

BioMarin CEO Jean-Jacques Bienaime said that the company was excited to bring the first approved therapeutic option to the EU to treat LEMS.

“We are on track to launch amifampridine in the EU in mid-March and look forward to meeting with the FDA in early 2010 to determine the necessary regulatory path for this product in the US,” Bienaime said.

Amifampridine phosphate, was developed by the pharmaceutical unit (AGEPS) of the Paris Public Hospital Authority (AP-HP) and licensed from EUSA Pharma SAS.