The European Commission said Wednesday it had forced South African drugs giant Aspen to slash prices on six cancer drugs after finding it abused its market dominance to hike charges.

The firm agreed to cut the cost of the medicines, used for the treatment of some forms of blood cancer including leukaemia, by some 73 percent inside the EU, after a years-long probe.

"Aspen's commitments will save European health systems many dozens of million euros and will ensure that these crucial medicines remain available," European Commission competition chief Margrethe Vestager said.

"Today's decision gives a strong signal to other dominant pharmaceutical companies not to engage in abusive pricing practices to exploit our health systems."

The European Commission, the EU's executive arm, launched an investigation back in 2017 after Aspen increased prices of some of its medicines by several hundred percent.

The case was the Commission's first investigation into allegations of excessive pricing practices in the pharmaceutical industry.

The Commission said it "found serious concerns that Aspen's behaviour may be in breach of EU competition rules" after no "legitimate reasons" were provided for the firm's high profits.

"Aspen could achieve these price increases, because patients and doctors had mostly no alternatives to using these particular cancer medicines," the statement said.

"When national authorities tried to resist Aspen's requests for price increases, Aspen went as far as threatening to withdraw the medicines from the national list of reimbursable medicines and in some cases was ready to even withdraw from normal supply in the market."

Vestager said the prices for the drugs -- used by thousands of patients, including young children -- would now return to pre-2012 levels before the increases started.

The reduced prices will remain in force for 10 years and the company has committed to maintain the supply of drugs, the Commission said.

aro/del/dc