Stevenage based pharmaceutical firm Flynn Pharma says it will appeal against a huge fine imposed by the The Competition and Markets Authority for hiking the price of epilepsy drugs.

The firm was hit with a £5.2 million fine after a CMA investigation found it had raised the price of phenytoin sodium capsules by 2,600 per cent.

The firm said yesterday it would try to overturn the fine on the grounds the CMA investigation was ‘seriously flawed’.

It says its phenytoin sodium capsules are already cheaper than alternative drugs available in the UK and have been sold at a price negotiated with the Department of Health for the past nine years.

It says the CMA has invented a ‘novel theory’ by which to judge the amount that a firm producing generic or non-branded drugs can charge for them in relation to branded products and claims

the CMA’s decision could help ‘stunt investment’ in generic drugs leading to a reduction in supply and less choice for doctors and patients.

The company issued a statement saying: “Flynn Pharma Limited is disappointed that the CMA reached the decision it has in its case relating to phenytoin sodium capsules..

“The CMA has taken more than three and a half years to reach this decision which in Flynn’s view is based on a wholly flawed understanding of the UK pharmaceutical market. This has resulted in the CMA making a serious error in its decision which we believe may have unintended consequences on future investment in, and availability of, generics.”

Flynn says it will appeal to overturn the CMA’s findings in the courts.

Before September 2012, American firm Pfizer manufactured and sold the drugs to UK wholesalers and pharmacies under the brand name Epanutin and the prices of the drug were regulated.

But then Pfizer sold the UK distribution rights for Epanutin to Flynn Pharma, which de-branded the drug – meaning it was no longer subject to price regulation.

The amount the NHS was charged for 100mg packs of the drug rocketed from £2.83 to £67.50, before reducing to £54 from May 2014.

As a result of the price increases, NHS expenditure on the capsules increased from about £2m a year in 2012 to around £50m in 2013.