History
The development of amifampridine and its phosphate has brought attention to orphan drug policies that grant market exclusivity as an incentive for companies to develop therapies for conditions that affect small numbers of people.Amifampridine, also called 3,4-DAP, was discovered in Scotland in the 1970s, and doctors in Sweden first showed its use in LEMS in the 1980s.In the 1990s, doctors in the US, on behalf of Muscular Dystrophy Association, approached a small family-owned manufacturer of active pharmaceutical ingredients in New Jersey, Jacobus Pharmaceuticals, about manufacturing amifampridine so they could test it in clinical trials. Jacobus did so, and when the treatment turned out to be effective, Jacobus and the doctors were faced with a choice — invest in clinical trials to get FDA approval or give the drug away for free under a compassionate use program to about 200 patients out of the estimated 1500-3000 LEMS patients in the U.S.. Jacobus elected to give the drug away to this subset of LEMS patients, and did so for about twenty years.Doctors at the Assistance Publique – Hôpitaux de Paris had created a phosphate salt of 3,4-DAP (3,4-DAPP), and obtained an orphan designation for it in Europe in 2002. The hospital licensed the intellectual property on the phosphate form to the French biopharma company OPI, which was acquired by EUSA Pharma in 2007, and the orphan application was transferred to EUSA in 2008. In 2008 EUSA submitted an application for approval to market the phosphate form to the European Medicines Agency under the brand name Zenas.
EUSA, through a vehicle called Huxley Pharmaceuticals, sold the rights to 3,4-DAPP to BioMarin in 2009, the same year that 3,4-DAPP was approved in Europe under the new name Firdapse.The licensing of Firdapse in 2010 in Europe led to a sharp increase in price for the drug. In some cases, this has led to hospitals using an unlicensed form rather than the licensed agent, as the price difference proved prohibitive. BioMarin has been criticized for licensing the drug on the basis of previously conducted research, and yet charging exorbitantly for it. A group of UK neurologists and pediatricians petitioned to prime minister David Cameron in an open letter to review the situation. The company responded that it submitted the licensing request at the suggestion of the French government, and points out that the increased cost of a licensed drug also means that it is monitored by regulatory authorities (e.g. for uncommon side effects), a process that was previously not present in Europe. A 2011 Cochrane review compared the cost of the 3,4-DAP and 3,4-DAPP in the UK and found an average price for 3,4-DAP base of £1/tablet and an average price for 3,4-DAP phosphate of £20/tablet; and the authors estimated a yearly cost per person of £730 for the base versus £29,448 for the phosphate formulation.Meanwhile, in Europe, a task force of neurologists had recommended 3,4-DAP as the firstline treatment for LEMS symptoms in 2006, even though there was no approved form for marketing; it was being supplied ad hoc.