A new drug described as one of the most important advances in treating breast cancer in the past 20 years will not be approved on the NHS, draft guidance says.
The Institute of Cancer Research (ICR) condemned the move by the National Institute for Health and Care Excellence (Nice), calling for urgent discussions to reduce the price of Ibrance (palbociclib).
Research presented at the world's biggest cancer conference in Chicago last June showed that women taking Ibrance with another common drug (an aromatase inhibitor) lived 10 months longer without their cancer getting worse as those given standard treatment.
Typically, they enjoyed 24.8 months without their cancer progressing compared with 14.5 months for women on usual treatment. Some women had much better results.
At the time, Baroness Delyth Morgan, chief executive of Breast Cancer Now, said Ibrance was part of a new class of drugs and a "significant step forward" for treating women.
Ibrance is for women with hormone-positive, HER2 negative breast cancer that has spread around the body.
These women are usually treated with 20p-a-day aromatase inhibitors (AIs).
Ibrance was approved for women in the US in February 2015.
Dr Nicholas Turner, team leader in molecular oncology at the ICR, who also works at the Royal Marsden and was on the Nice panel for the drug, led the ICR's clinical trial of Ibrance.
He said: "Palbociclib is one of the most important advances in treating the most common type of breast cancer in 20 years.
"Clinical trials show the drug can substantially slow the progression of the disease and help delay chemotherapy, which often has life-limiting side-effects.
"It is very disappointing that palbociclib is not being made available to patients, but cost is the limiting factor.
"If the manufacturer, Nice and NHS England can find a way of making this treatment available for patients, they will substantially improve the lives of patients with breast cancer."
Ibrance is given as a once-daily capsule with an aromatase inhibitor. It costs £2,950 for a pack of 21 capsules.
Nice said it was unclear if overall survival definitely improved during clinical trials and cited too-high costs.
There are around 45,000 new cases of breast cancer each year in England. It is thought 5,500 people would be eligible for treatment with Ibrance.
Professor Carole Longson, director of the centre for health technology assessment at Nice, said: "The committee needs more evidence of the drug's impact on overall survival of people with breast cancer.
"However, even when allowing for these potential benefits, it was still not enough to make palbociclib cost effective at its current price."
Baroness Morgan said: "This is the clearest illustration to date that the drug appraisal system is totally unfit for purpose in assessing first-in-class breast cancer medicines.
"For women with incurable breast cancer in England to potentially be made to wait years for such a promising drug, while NHS bodies and pharmaceutical companies haggle over pricing, would be totally unacceptable.
"Palbociclib could benefit a large proportion of metastatic breast cancer patients and may even be the closest thing these women would have to a cure in their lifetime.
"This must not be the end for this pioneering drug and we now urge Pfizer and Nice to work together to explore every possible solution to ensure it is made available to NHS patients.
"Pfizer must urgently reconsider their decision not to offer the NHS any form of discount on the list price."
She said the decision also showed the "systemic flaws" of the Nice appraisal process, adding that it now needed "wholescale reform".