Amifampridine phosphate to treat Lambert Eaton Myasthenic Syndrome (LEMS) gets EU marketing approval

Amifampridine phosphate to treat the rare autoimmune disease Lambert Eaton Myasthenic Syndrome (LEMS) has been given marketing approval in Europe.

Amifampridine  phosphate, which contains 3,4-diaminopyridine has been granted marketing approval by the European Commission to treat Lambert Eaton Myasthenic Syndrome (LEMS), BioMarin Pharmaceutical Inc. announced.

Amifampridine phosphate is the first approved treatment for LEMS, thereby conferring orphan drug protection and providing ten years of market exclusivity in Europe.

Amifampridine phosphate has also received orphan drug designation in the US.

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

“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,” stated Jean-Jacques Bienaime, Chief Executive Officer of BioMarin.

BioMarin will also evaluate the amifampridine phosphate opportunity in a number of countries outside the U.S. and Europe as well as the best development strategy for amifampridine in other indications, he said.

Amifampridine phosphate is the fourth approved product of BioMarin.

What is Lambert Eaton Myasthenic Syndrome (LEMS)?

Lambert Eaton Myasthenic Syndrome (LEMS) is a rare autoimmune disease with the primary symptoms of muscle weakness.

Muscle weakness in LEMS is caused by autoantibodies to voltage gated calcium channels leading to a reduction in the amount of acetylcholine released from nerve terminals.

Lambert Eaton Myasthenic Syndrome affects about four to ten per million, or approximately 2,000 to 5,000 patients in the EU and 1,200 to 3,100 patients in the U.S, it is estimated.

Approximately 50 percent of LEMS patients diagnosed have small cell lung cancer.

Patients with Lambert Eaton Myasthenic Syndrome (LEMS) typically present with fatigue, muscle pain and stiffness.

The weakness is generally more marked in the proximal muscles particularly of the legs and trunk. Other problems include reduced reflexes, drooping of the eyelids, facial weakness and problems with swallowing.

Patients often report a dry mouth, impotence, constipation and feelings of light headedness on standing. On occasion these problems can be life threatening when the weakness involves respiratory muscles.

A diagnosis of Lambert Eaton Myasthenic Syndrome (LEMS) is generally made on the basis of clinical symptoms, electromyographic testing and the presence of autoantibodies against voltage gated calcium channels.

Current treatment of Lambert Eaton Myasthenic Syndrome (LEMS) can consist of strategies directed at the underlying malignancy if one is present.

Unfortunately, therapy of small cell lung cancer is limited and outcomes are generally poor. Immunosuppressive agents have been tried but success is limited by toxicity, and difficulty administering the regimens.

A mainstay of therapy has been 3,4-DAP but its use in practice has been limited by the drug’s availability. This problem will be addressed by the introduction of BioMarin’s product.

BioMarin develops and commercializes innovative biopharmaceuticals for serious diseases and medical conditions.

BioMarin’s product portfolio comprises four approved products and multiple clinical and pre-clinical product candidates.

Approved products include Naglazyme (galsulfase) for mucopolysaccharidosis VI (MPS VI), a product wholly developed and commercialized by BioMarin; Aldurazyme (laronidase) for mucopolysaccharidosis I (MPS I), a product which BioMarin developed through a 50/50 joint venture with Genzyme Corporation.

Kuvan (sapropterin dihydrochloride) tablets, for phenylketonuria (PKU), developed in partnership with Merck Serono, a division of Merck KGaA of Darmstadt, Germany; and 3,4-diaminopyridine (amifampridine phosphate), which has been approved by the European Commission for the treatment of Lambert Eaton Myasthenic Syndrome (LEMS).

Other product candidates include PEG-PAL (PEGylated recombinant phenylalanine ammonia lyase), which is currently in Phase II clinical development for the treatment of PKU and GALNS (N-acetylgalactosamine 6-sulfatase), which is currently in Phase I/II clinical development for the treatment of MPS IVA.