Drugmaker Merck & Co. (MRK) Saturday said its experimental blood thinner vorapaxar in combination with standard of care was seen to significantly reduce cardio vascular events in heart patients, but saw an increase in bleeding especially in those who have had a stroke.
The company had announced the outcome of the study last month, but did not provide the details then. Now, the mixed results have given rise to concerns whether the company will go ahead to seek regulatory approval for the drug candidate.
Results from the TRA-2P (Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events) TIMI 50 study of vorapaxar in patients with a prior history of cardiovascular events or disease was presented at the American College of Cardiology 61st Annual Scientific Session and published concurrently online in the New England Journal of Medicine.
TRA-2P included 26,449 stable patients at 1,032 sites in 32 countries. These patients had experienced a stroke or heart attack no less than 2 weeks and no more than 12 months before randomization, or who had peripheral arterial disease or PAD.
The goal of the study was to evaluate the efficacy and safety of vorapaxar compared with placebo plus standard of care in the secondary prevention setting. Vorapaxar was administered at a 2.5 mg daily maintenance oral dose for more than one year. The median follow-up time was 30 months.
The addition of vorapaxar to standard of care such as aspirin or thienopyridine or both reduced the risk of cardiovascular or CV death, heart attack, stroke or urgent coronary revascularization by 12 percent compared to placebo plus standard of care. The addition of vorapaxar also resulted in a 13 percent reduction in CV death, heart attack and stroke.
However, vorapaxar significantly increased moderate or severe bleeding in 4.2 percent of patients compared to 2.5 percent in the placebo population. Rates of intracranial hemorrhage were 1 percent in the vorapaxar arm compared to 0.5 percent in placebo, primarily driven by patients with a history of stroke. In patients without a history of stroke, the rates of intracranial hemorrhage were 0.6 percent in the vorapaxar arm compared to 0.4 percent in placebo.
Merck said it was the first time that an anti-thrombotic medicine added to the standard of care has been shown to provide an additional, significant reduction in cardiovascular events in the secondary prevention setting.
MRK closed on Friday at $38.01, up $0.41 or 1.09 percent, on a volume of 10.77 million shares.
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