The Competition and Markets Authority has assured the NHS that the pharmaceutical company Aspen will not charge more than its current prices for six cancer drugs.

The regulator cleared up any lingering uncertainty over potential price rises by insisting Aspen’s commitment to lower pricing across Europe, a pledge made legally binding under European Union antitrust rules last year, will continue to be fulfilled in the UK and not be affected by Brexit.

Aspen reduced its prices by an average of 73 per cent, ensuring the supply of the six drugs for five years and promising to carry on supplying or making its marketing authorisation available to other suppliers for another five years.

The CMA said Aspen’s commitments “became legally binding under EU law after the UK was no longer part of the EU” and insisted it would “have effective mechanisms to monitor and ensure compliance by Aspen following the UK’s exit from the EU.”

“The CMA has now assisted the NHS to secure binding undertakings from Aspen, under the law of England and Wales, which enshrine the UK elements of the commitments and are enforceable by UK courts, including in relation to the supply of these drugs in Northern Ireland and Scotland,” the CMA said.

In May 2017, the European Commission opened an investigation into concerns Aspen was engaging in excessive pricing relating to six off-patent cancer medicines mainly used to treat leukaemia and other haematological cancers.