Clinical Studies with Sirolimus, Zotarolimus, Everolimus and Biolimus A9 Drug- Eluting Stent Systems

The introduction of the drug-eluting stent (DES) has revolutionized the field of interventional cardiology during the past decade. Initial pivotal randomized clinical trials showed a large reduction in restenosis rates and the need for repeat intervention with DES compared with bare-metal stents. The three main components of a DES are 1) the stent platform, 2) a coating facilitating elution of the drug (mostly a polymer), and 3) a antiproliferative/anti-inflammatory drug. Currently, two classes of drugs are widely used in DES, Taxanes, including its best-known member Paclitaxel, and Rapamycins, which include Sirolimus and its analogues such as Everolimus, Zotarolimus and Biolimus A9. The first DES to receive United States Food and Drug Administration approval was the Sirolimus-eluting stent. Recently, two other stent types eluting a Sirolimus-analogue were approved; the Zotarolimus-eluting stent and the Everolimuseluting stent. Biolimus A9-eluting stents, using biodegradable polymers, are currently approved and marketed outside of the United States. This review article focusses on the clinical studies that have been performed with DES eluting Sirolimus or its analogues.