It looks like investors will have to wait a little longer to get news about Eli Lilly's (NYSE:LLY) potentially game-changing pipeline compound prasugrel. On Monday, the FDA pushed back its target review date for Lilly's marketing application of the heart drug by three months, to Sept. 26.

Lilly is trying to get prasugrel approved as a treatment for acute coronary syndrome sufferers. The drug's PDUFA date was set for tomorrow; instead, Lilly now gets to join a large and ever-growing list of drugmakers who've had their New Drug Applications delayed this year. Investors shouldn't read too much into this prasugrel holdup, since the FDA has been slowing up its reviews of nearly every type and class of drug. In other words, the postponement likely springs from an FDA issue, not a prasugrel issue.

No matter what caused the delay, its biggest beneficiaries are Bristol-Myers Squibb (NYSE:BMY) and Sanofi-Aventis (NYSE:SNY), since their anticoagulant Plavix will be most affected by prasugrel competition. In phase 3 testing, Lilly specifically targeted Plavix as its main competition, studying prasugrel's effectiveness versus that of the longtime billion-dollar blockbuster drug.

In the first quarter alone, Bristol-Myers brought in $1.3 billion in Plavix sales. The market for prasugrel clearly has blockbuster potential if it can get through the sometimes headache-inducing FDA approval process. If prasugrel can't get approved, though, the stakes for Lilly will be high, since it's already facing a countdown to patent expiration on its antipsychotic schizophrenia drug Zyprexa.

In the first quarter, Zyprexa accounted for 23% of Lilly's sales. Whether its review occurs in three months or sometime in the future, Lilly needs potential blockbuster compounds like prasugrel -- and its partner Amylin Pharmaceuticals' (NASDAQ:AMLN) long-acting version of Byetta -- on the market to fill in for Zyprexa's pending downfall.