Disclosed are protein kinase inhibitors of Formula Ia and Ib, compositions comprising such inhibitors, and methods of use, thereof. More particularly, these compounds and compositions are inhibitors of Aurora-A (Aurora-2) and Aurora-B (Aurora-1) protein kinase. Also disclosed are methods of using these compounds and compositions to prevent and treat diseases associated with protein kinases, especially diseases associated with Aurora-A or Aurora-B, such as cancer.
