Daiichi Sankyo Company, Limited and Eli Lilly and Company announced that enrolment of new patients and administration of the study drug in two small Prasugrel-related pharmacodynamic clinical trials are being suspended until protocol amendments can be completed and approved.

The amendments are due to preliminary results from pharmacokinetic analyses, including patients and healthy subjects/volunteers, indicating that a dose adjustment may be appropriate for certain subpopulations.

These protocol amendments should not be interpreted to represent the outcome of the overall Prasugrel clinical development programme.

The two small phase II pharmacodynamic studies compare the levels of inhibition of platelet aggregation (IPA) in patients with coronary artery disease taking the investigational antiplatelet agent Prasugrel or clopidogrel (Plavix). Neither study has an efficacy endpoint. Patient enrolment will resume as soon as additional analyses of pharmacokinetic and clinical data are completed, and the protocols are amended and approved by institutional review boards.

"We are suspending enrolment in these two small pharmacodynamic trials so that we can amend current protocols. These amendments are strictly protocol-related and do not provide a basis for inferring overall outcomes of other prasugrel trials," said J. Anthony Ware, M.D., Lilly cardiovascular platform leader for prasugrel.

Cardiovascular disease is the leading cause of death in the US and worldwide, killing 16.7 million people each year. Acute heart attacks and unstable angina, called acute coronary syndrome, affect more than 840,000 Americans each year and 800,000 in Europe. Utilizing current medical interventions and treatments, 300,000 people continue to experience recurrent heart attacks and 450,000 people die from heart attacks annually in the US.

Daiichi Sankyo Company, Limited and Eli Lilly and Company are co-developing prasugrel, an investigational oral antiplatelet agent invented by Daiichi Sankyo and its Japanese research partner Ube Industries, Ltd., as a potential treatment, initially for patients with acute coronary syndrome undergoing PCI. Prasugrel works by inhibiting platelet activation and subsequent aggregation by blocking the P2Y12 adenosine diphosphate (ADP) receptor on the platelet surface. Antiplatelet agents prevent platelets from clumping or sticking together, which can result in clogged arteries and may lead to heart attack or stroke.