Brussels, 06 Mar 2006
For years patient groups have criticised pharmaceutical companies for failing to invest in the development of drugs for rare diseases. But it appears that of those drugs created to treat rare conditions, very few are being approved.
According to a group of scientists at the Institute for Pharmacological Research in Milan, Italy, just over seven per cent of drug applications for treating people with rare diseases were approved in Europe between 2000 and 2004. During the same period, 79 per cent of other drug applications submitted to the European Agency for the Evaluation of Medicinal Products (EMEA) were given the green light. Some 5,000 conditions remain untreatable with medication, while between 24 and 36 million people in Europe alone suffer from rare diseases.
'It's difficult to find a balance between the urgent need for drugs for patients with rare diseases and guaranteeing their quality, efficacy, safety and, where necessary, making comparisons with existing drugs,' says one of the researchers, Professor Silvio Garattini.
Professor Garattini suspects that the lack of reliable methods for evaluating orphan drugs, which must be tested on a small number of people, is probably responsible for the poor quality of applications submitted to the EMEA. 'However, it is clear that less stringent criteria are acceptable for orphan drugs than for drugs for more common diseases, particularly in view of the small number of patients,' he said.
Dr Jeffrey Aronson from the editorial board of the British Journal of Clinical Pharmacology, in which the research was published, claims that the situation in Europe also contrasts sharply with that of the US, where there are more incentives for carrying out research into orphan drugs. The figures suggest however that while the US does have a higher approval rate than Europe (231 out of 1,100 over 19 years - 21 per cent - compared to 18 out of 255 over 3.5 years - 7.06 per cent), Europe actually submits more applications for approval than the US (255 over 3.5 years, compared to 1,100 over 19 years).
Between August 2000 and December 2004, of the 255 drugs for rare diseases submitted to the EMEA, only 18 were approved on the basis of epidemiological data, medical plausibility and potential benefit. However, ten of these drugs were authorised under 'exceptional circumstances', meaning that the dossier was not quite complete, and that additional studies are required in order for the developers to maintain their marketing authorisation.
The approved drugs will be used for treating conditions such as rare forms of leukaemia, Fabry disease, which affects the body's ability to break down lipids, and Wilson's disease, in which copper build-up can damage vital organs.