The FDA’s Cardiovascular and Renal Drugs Advisory Committee voted 10-1 in favor of approval for vorapaxar, Merck's novel thrombin receptor antagonist. The “roller coaster ride” cliché might have been invented for this drug, which was the subject of tremendous early hopes followed by major disappointments and, finally, a subsequent revival.
The committee voted in favor of the drug for use as an adjunctive therapy for the reduction of atherothrombotic events in patients with a history of myocardial infarction (MI). Panel chairperson Philip Sager said that “this drug addresses a real unmet medical need and can make a real difference for patients.”
The University of Colorado’s Mori Krantz provided the one negative vote, though in his comments he indicated that he was not entirely opposed to approval. He characterized his vote as a “formal dissent” and said that he wanted to get on the record his concerns about the large number of patients who would need to be treated with vorapaxar to prevent a single event and his fear that the bleeding complications observed in the study might be amplified in the real world.
Sanjay Kaul said that Merck ”convincingly demonstrated that the benefit exceeded the risk in the selected patient cohort. Like all development programs, it has it’s fair share of warts, but there is an unmet need in this population where we have no safe and effective therapies available. Hopefully, if approved it will be used in scenarios that optimize its benefit-risk profile.”
The panel spent much of the day wrestling with the complex questions raised by the drug’s troubled history, in which one large trial, TRACER, was stopped early due to high rates of serious bleeding and the other trial, the TRA2P trial, was redesigned in midstream. But ultimately the panel believed that TRA2P had been able to show that vorapaxar was effective in a post-MI population in which patients with a history of stroke were excluded.