The UK's NICE says it does not believe Johnson & Johnson's Imbruvica to treat chronic lymphocytic leukaemia (CLL) is a cost-effective use of NHS resources.
Draft guidance issued by NICE said it is not minded to approve Imbruvica (ibrutinib) for NHS prescribing because of "numerous uncertainties in the evidence base and economic modelling" for the drug.
The preliminary verdict - which is open for comment until 22 March - has been greeted with disbelief by J&J's Janssen unit, which sells the drug in the UK, as well as patient groups.
The decision "sits in stark contrast to the recommendations of 48 countries globally which have opted to fund or reimburse the medicine including 27 European countries, most recently in Greece", said the company.
The list price for Imbruvica, which is used to treat adult patents with relapsed or refractory CLL who are not suitable for chemotherapy, is around £56,000 per year, although Janssen had agreed an undisclosed discount with the Department of Health.
Meanwhile, chair of the CLL Support Association David Innes said the decision was a blow because "CLL patients have historically had limited access to effective and innovative treatments".
He suggested that the reason for NICE's decision is that median survival data from clinical trials of the drug are uncertain "because patients are responding well and living longer".
That view was echoed by Zack Pemberton-Whiteley, head of campaigns and advocacy at Leukaemia CARE, who said the preliminary finding "demonstrates the numerous flaws in NICE's methodology when dealing with uncertainty”.
"With the UK cancer survival outcomes continuing to lag far behind the rest of Europe, decisions like this cannot be allowed to continue", he added.
Janssen notes that Imbruvica is available on the Cancer drugs Fund (CDF) - in fact it is the CDF's most requested CLL drug - but with a new version of the Fund due to come into effect from 1 July there are fears that patients could increasingly be denied access to new treatments.
"The current NICE appraisal process is not fit-for-purpose in responding to the needs of cancer patients and the healthcare professionals who treat them”, according to Janssen UK managing director Mark Hicken.
"This is a worrying sign for people living in England and is, unfortunately, likely to be much more common under the new CDF process approved by the NHS England board last week."