Twenty consultants and a patient group have written an open letter to Prime Minister David Cameron and health secretary Andrew Lansley calling for an investigation.
They claim companies are exploiting orphan drugs rules to charge 'exorbitant' amounts for treatments otherwise available for much less.
The EU Orphan Regulation is designed to encourage drug companies to research rare diseases. But the authors claim many companies are instead applying for licences to repackage existing drugs for rare diseases.
The sole licence allows companies to charge dozens of times higher prices for drugs than existing treatments, the letter said.The authors wrote: ‘In the present economic situation it seems vital to ensure that systems are in place to prevent excessive commercial profits being made at the expense of patients and public spending.'
The consultants conclude: ‘Legislation on orphan drugs, far from encouraging the development of new treatments for orphan diseases, is severely limiting the availability of existing treatments.
‘We believe that the MHRA and DoH should not just state the rules but should act now to progress the issue of unfairness upwards, so as to instigate change.’
In an accompanying article, Timothy Cox and colleagues at the University of Cambridge said orphan drug pricing hampers access to treatment and may warrant a competition law investigation.
They added current high pricing contravenes the aim of the Orphan Regulation, which states: ‘Patients suffering from rare conditions should be entitled to the same quality of treatment as other patients.’