Friday, the Food and Drug Administration gave the go-ahead to Eli Lilly and Company’s and Daiichi Sankyo Co Limited’s anti-clotting drug prasugrel, yet that did not manage to put to rest investors’ concerns regarding cancer and bleeding, which they say could give rise to low demand.

The former company’s shares dropped by over 2 percent when investors voiced their worries that safety issues might come to limit the use of the drug and thus hinder the product to gain market share to the loss of major rival Bristol-Myers Squibb Company and Sanofi-Aventis SA's Plavix.

In a statement made to Reuters, Natixis Bleichroeder analyst Jon LeCroy said that were the drug to be FDA approved, it would have the most restrictive label.

The FDA issued its report on the drug before a meeting concerning its approval is to be held on Tuesday, when the agency’s officials will vote on the matter and decide whether to let the companies put their product on the market.

Lilly and Daiichi have been waiting for an answer from the FDA for over a year now, while federal health officials have delayed making a decision twice within that time-frame.

Prasugrel, which the two companies are planning to market under the Effient brand name, is aimed at reducing heart attacks in patients that have undergone angioplasty.

The drug’s effectiveness has been proved via clinical trials, which according to the regulatory staff that recommended its approval, showed that prasugrel was more effective than active drugs and not just placebos, adding that the benefits weighed more than the risks entailing excessive bleeding.