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This medicine is now known as amifampridine.

On 18 December 2002, orphan designation (EU/3/02/124) was granted by the European Commission to Agence Générale des Equipements et Produits de Santé - Etablissement Pharmaceutique des Hôpitaux de Paris (AGEPS - EPHP), France, for 3,4 diaminopyridine phosphate for the treatment of Lambert-Eaton myasthenic syndrome.

The sponsorship was transferred to OPi, France, in April 2006. OPi changed its name to EUSA Pharma SAS in February 2008.

The sponsorship was subsequently transferred to BioMarin Europe Ltd, United Kingdom, in June 2010.

3,4 diaminopyridine phosphate has been authorised in the EU as Firdapse since 23 December 2009.

The sponsorship was transferred to BioMarin International Limited - Ireland, in June 2018.

Please note that this product was withdrawn from the Community Register of designated orphan medicinal products in December 2019 at the end of the 10-year period of market exclusivity.

Key facts

Active substance
3,4-diaminopyridine phosphate (amifampridine)
Medicine name
Disease / condition
Treatment of Lambert-Eaton myasthenic syndrome
Date of first decision
EU designation number

Sponsor's contact details

BioMarin International Limited
County Cork P43 R298

Patients' organisations

For contact details of patients’ organisations whose activities are targeted at rare diseases, see:

  • European Organisation for Rare Diseases (EURORDIS), a non-governmental alliance of patient organisations and individuals active in the field of rare diseases.

  • Orphanet, a database containing information on rare diseases, which includes a directory of patients’ organisations registered in Europe.

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