Bafetinib

Bafetinib (formerly known as INNO-406) is an orally bioavailable, rationally designed, dual Bcr-Abl and Lyn-kinase inhibitor. According to a study published in the journal Blood (Dec. 1, 2005), bafetinib is 25 to 55 times more potent than imatinib in vitro, and at least 10 times as effective as imatinib mesylate in suppressing the growth of Bcr-Abl bearing tumors. Bafetinib has demonstrated activity in 12 of 13 imatinib-resistant cell lines.

In addition to its Bcr-Abl inhibitory properties, bafetinib is a potent and specific inhibitor of Lyn and Fyn kinases. These kinases are reported to be involved in both solid and hematological cancers. Lyn kinase’s involvement in the B-cell signaling pathway led CytRx to evaluate bafetinib in B-cell malignancies such as CLL.

The Company is evaluating bafetinib in the ENABLE Phase 2 clinical trial in high-risk B-cell chronic lymphocytic leukemia (B-CLL), and recently announced that results from that clinical trial demonstrated bafetinib's clinical activity and preliminary safety in patients with relapsed or refractory B-CLL. CytRx plans to seek a partner for further development of bafetinib, and holds rights to bafetinib in all territories except Japan.

In November 2008, CytRx announced that bafetinib demonstrated clinical responses in patients with CML in an international Phase I dose-ranging clinical trial conducted in patients with CML and other leukemias that have a certain mutation called the Philadelphia Chromosome (Ph+) and are intolerant of or resistant to Gleevec and, in some cases, second-line tyrosine kinase inhibitors such as dasatiniband nilotinib). INNO-406 has been granted Orphan Drug Status for the treatment of Philadelphia chromosome-positive (Ph+) CML by the FDA.

CytRx holds rights to bafetinib for all territories except Japan.