Swiss group Roche’s new melanoma drug Zelboraf has been rejected in a preliminary ruling by Britain’s healthcare cost agency, triggering a fresh clash between the world’s biggest maker of cancer drugs and NICE. The National Institute for Health and Clinical Excellence said on Friday that while Zelboraf was effective for melanoma patients with a particular genetic mutation, its longer-term effect on survival was uncertain. NICE said that, as a result, it could not recommend the drug as a cost-effective treatment for the deadliest form of skin cancer within the state-run National Health Service (NHS), even after an undisclosed price discount offered by Roche.