Two new "breakthrough" breast cancer drugs have been approved for use at NHS England by the National Institute for Health and Care Excellence (NICE).

Palbociclib (Ibrance) and ribociclib (Kisqali) have been shown to slow the advance of late stage cancer for as much as to 2 years.

The results of clinical trials demonstrated that the drugs reduced the speed of tumour growth, meaning that women could delay chemotherapy – with its negative side effects – and live a relatively normal life for longer.

Palbociclib and ribociclib work by inhibiting the action of two proteins known as CDK 4 and CDK 6. They only need to be taken once a day in conjunction with another drug.

Around 8,000 people will now have access the medication. Every year, around 45,000 people are diagnosed with breast cancer in England.

Initially, palbociclib had been rejected by NICE because it was too expensive, but the institute later renegotiated the price with the drug's manufacturer, Pfizer, in a confidential agreement.

The list price of one cycle of both drugs is £2,950 – which amounts to 21 capsules of palbociclib and 63 ribociclib.

Professor Carole Longson, director of the Centre for Health Technology Evaluation at NICE, said: "The committee heard that by postponing disease progression, palbociclib and ribociclib may reduce the number of people who are exposed to the often unpleasant side effects of chemotherapy, and delay the need for its use in others.

"We are pleased therefore that the companies have been able to agree reductions to the price of palbociclib and ribociclib to allow them to be made routinely available to people with this type of breast cancer."

Professor Nicholas Turner, a Professor of Molecular Oncology at the Institute of Cancer Research (ICR), and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust, was one of the clinical experts on the NICE panels for both drugs, and led clinical trials examining the efficacy of palbociclib.

"The development of this brand new class of cancer drug is one of the most important breakthroughs for women with advanced breast cancer in the last two decades," he said.

"I'm delighted that NICE and the manufacturers have managed to come to an agreement over the price and economic modelling of palbociclib and ribociclib, so that many more women can access this much-needed new type of treatment on the NHS."

However, Paul Workman, ICR chief executive, added it was "frustrating that the approval of palbociclib on the NHS was such a long, drawn-out process", even though the, "manufacturer made the drug available for free in the meantime".

"We need NICE to work together with industry on a new process for evaluation where companies are encouraged to come forward with their best price much earlier in discussions. The current system is taking too long and prices still remain high."

Woman's mammogram
A doctor exams mammograms, a special type of X-ray of the breasts, which is used to detect tumours as part of a regular cancer prevention medical check-up at a clinic in Nice, south eastern France. Reuters