MLN3897 is part of Millennium's larger inflammatory development program that includes six product candidates and is one of several small molecules included in the Company's small molecule inflammation collaboration with sanofi-aventis. MLN3897 (sanofi-aventis AVE9897) is an orally active, small molecule antagonist of CCR1, a chemokine receptor found on the surface of various cells in the immune system and involved in a number of inflammatory disorders. In the Phase I studies, results showed MLN3897 to be well-tolerated and to exhibit dose dependent blockage of the CCR1 receptor. Since CCR1 is involved in the recruitment of white blood cells in response to sites of inflammation, effectively blocking CCR1 could have a significant effect on RA disease progression and other inflammatory diseases. A Phase II trial to evaluate MLN3897 in RA is underway.

For more information about MLN3897 clinical trials, patients and physicians can contact the Millennium Call Center at (800) 589-9005.  Information about ongoing clinical research studies may also be found at http://www.clinicaltrials.gov.

MLN3701 is an orally active, small molecule antagonist of CCR1 - the same class of compound as MLN3897. It is currently in pre-clinical testing, and is being developed as part of our collaboration with Sanofi-Aventis.

CCR1 is a chemokine receptor expressed on the surface of various cells in the immune system, including monocytes, macrophages and T-lymphocytes, that participate in inflammatory responses. Several different chemokines can bind to CCR1, including macrophage-inflammatory protein 1-alpha (MIP-1alpha) and RANTES. CCR1 thus plays a role in the recruitment of white blood cells in response to sites of inflammation.

Millennium is developing small molecules that block the CCR1 receptor as potential drugs for treating chronic inflammatory disorders, including rheumatoid arthritis and multiple sclerosis.