Pfizer is to offer its breast cancer drug Ibrance free to the NHS while cost regulators decide whether it should be routinely funded in the UK.

Ibrance (palbociclib) is the first of a new type of drug that increases the effect of aromatase inhibitors, which block the production of the hormone oestrogen, stopping its ability to stimulate some breast cancers to grow.

The drug was approved in November 2016 as a first-line treatment for hormone receptor (HR) positive, HER2 negative locally advanced or metastatic breast cancer, the first of a new class of drugs that work by inhibiting two crucial cell division proteins called CDK4 and CDK6.

Clearance came on the back of data from three randomised trials showing that when Ibrance was administered in combination with an endocrine therapy patients lived on average 24.8 months without their disease getting worse, compared to 14.5 months in those taking letrozole, stalling growth of the cancer by around 10 months.

However, in February this year the National Institute for Health and Care Excellence published draft guidelines rejecting the drug, which costs nearly £80,000 for a full course of treatment, after concluding that although the progression free survival benefit was likely to result in some improvement in overall survival, this could not be quantified from clinical trials undertaken.

Following the provisional rejection campaigners – alongside leading charity Breast Cancer Now – called on Pfizer and NICE to “explore every possible solution to ensure the drug is made available to NHS patients,” the charity said.

The appraisal is now effectively on pause while Pfizer presents further clinical data on the drug, during which time patients will be treated for free under the ‘Ibrance Patient Programme’. This is expected to run for up five months, closing six weeks after NICE issues final guidance on the drug, or on the 30th September 2017, whichever is earlier.

“This is an unexpected lifeline for thousands of women living with this type of breast cancer. We are delighted that Pfizer have listened to our campaigners and have found a way to enable patients to access this first-in-class drug in the short term,” said Fiona Hazell, director of policy and engagement at Breast Cancer Now.

“While only an interim measure, more than sixteen women every day could have their lives changed by this drug during this window. Palbociclib can offer a large proportion of patients with incurable metastatic breast cancer significant extra time before their disease progresses – time that can be truly invaluable to them and their loved ones.

“However, D-Day for palbociclib is still to come and this temporary fix cannot hide the desperate need for Pfizer, NICE and the SMC to do everything they can to ensure this drug is made routinely available on the NHS beyond the timeline of this scheme.”