Merck’s Zontivity approved in US
Merck’s new cardiovascular treatment Zontivity (vorapaxar) has been approved by the FDA to reduce the risk of heart attack, stroke and death in high risk patients.
Zontivity is the first in a new class of drug, called a protease-activated receptor-1 (PAR-1) antagonist. It is an anti-platelet agent, designed to decrease the formation of blood clots, and thereby cut risk of heart attack and stroke.
The drug had once been earmarked for peak annual sales of up to $5 billion, but concerns about its safety which emerged in clinical trials – specifically the risk of dangerous, excessive bleeding – means it is unlikely to hit such heights, but could still earn well in excess of the $1 billion mark.
The oral treatment is aimed at reducing the risk of heart attack, stroke, cardiovascular death, and revascularisation surgery, needed to restore blood flow to the heart in patients with a previous heart attack or blockages in the arteries to the legs.
Like other antiplatelet treatments, Zontivity increases the risk of bleeding, including life-threatening and fatal bleeding. Bleeding is the most commonly reported adverse reaction in people taking Zontivity, and the drug carries a boxed warning to highlight this risk.
The drug’s US licence states that Zontivity must not be used in people who have had a stroke, transient ischemic attack (TIA), or bleeding in the head, because the risk of bleeding in the head is too great.
“In patients who have had a heart attack or who have peripheral arterial disease, this drug will lower the risk of heart attack, stroke, and cardiovascular death. In the study that supported the drug’s approval, Zontivity lowered this risk from 9.5% to 7.9% over a three-year period – about 0.5% per year,” said Ellis Unger, M.D., director of the Office of Drug Evaluation I in the FDA’s Center for Drug Evaluation and Research.
In a clinical trial with over 25,000 participants, Zontivity, added to other anti-platelet agents (generally aspirin and clopidogrel), reduced the rate of a combined endpoint of heart attack, stroke, cardiovascular death, and urgent procedures to improve blood flow to the heart (coronary revascularisation) when compared to an inactive pill (placebo).
Other cardiovascular candidates
Merck has two other promising cardiovascular drug programmes. The company has just signed a major deal with Bayer to share the right to the German company’s pulmonary arterial hypertension drug Adempas, plus a number of other candidates in the same class in Bayer’s pipeline.
Meanwhile in Phase 3 is Merck’s atherosclerosis drug anacetrapib, a member of the CETP inhibitor class in which has seen numerous other molecules have failed. Phase 3 trials of the drug will be complete in 2017, but the drug could earn in excess of $3 billion if it lives up to early promise of raising HDL or ‘good’ cholesterol and lowering LDL or ‘bad’ cholesterol, and thereby improving cardiovascular health.
