Merck & Co Inc's experimental blood clot-preventing drug vorapaxar should be approved, based on "robustly positive" clinical trial results, according to a preliminary review of the data by the U.S. Food and Drug Administration.
The review, posted on the FDA's website on Monday, comes two days ahead of a meeting of outside medical experts who are expected to recommend whether it should be approved. The FDA usually follows the advice of its advisory panels.
The drug, which would be sold under the brand name Zontivity, is designed to prevent heart-related deaths, cardiac arrests and strokes in patients who have had a recent heart attack. It would not be recommended for patients who have previously had a stroke because of an increased risk of bleeding in the brain.
Results from a trial known as TRA 2P "are sufficient to establish the effectiveness of vorapaxar for its proposed indication," the review found.
The main safety concern with the drug is bleeding, the review found, though it noted that the rate of fatal bleeding was low in the population for whom the drug is proposed.
The FDA did not recommend that the company establish a risk management program, nor did it recommend that the company conduct additional trials following approval.
Vorapaxar works by preventing blood cells, known as platelets, from clumping together and forming clots in the arteries, which can lead to heart attacks. Other anti-platelets include aspirin and Plavix, which is made by Bristol-Myers Squibb Co. Merck's drug works in a different way, by inhibiting a receptor known as PAR-1.
Each year about 525,000 Americans have heart attacks and about 190,000 have a second heart-related event, according to Merck. Standard therapy to prevent a second episode often includes treatment with aspirin and Plavix. Voraxapar would be given in addition to standard treatment.
During clinical trials, safety monitors found that patients who had previously had a stroke were at higher risk of bleeding in the brain and were instructed to stop taking the drug. Merck then focused its analysis on patients who had had a heart attack but no stroke.
Merck's shares rose 2.7 percent to $51.21 in early trading, helped also by news it had initiated its application to market a drug for patients with advanced melanoma.
The company also said it is pursuing strategic options for its animal health and consumer businesses and expects to complete any action this year.
(Reporting by Toni Clarke in Washington; Editing by Lisa Von Ahn and Bernadette Baum)