February 8, 2006

Avalon Pharmaceuticals has announced the completion of a three-week dosing regimen on the first patient in Cohort II and the initiation of Cohort I of its Phase I clinical trial of AVN944 in patients with advanced hematological malignancies. The first patient in Cohort II, which is focused on multiple myeloma and lymphoma patients, completed the three-week scheduled dosing at the University of Arkansas for Medical Sciences with no adverse side-effects. The first patient in Cohort I, focused on leukemia patients, began treatment last week at the University of Texas M.D. Anderson Cancer Center.

The Phase I clinical trial is designed as an open-label, repeat dose-escalation study for the evaluation of the safety and tolerability of AVN944 in adult patients with advanced hematological malignancies including those with leukemia, lymphoma or myeloma. The study is designed to determine the optimal dose with which to advance Phase II efficacy trials. In the current study, as many as 36 patients could receive AVN944 at or near this optimal dose. Currently, this trial is being conducted at four leading cancer centers in the United States, including the University of Arkansas for Medical Sciences, The University of Texas MD Anderson Cancer Center, Stanford University, and The Ohio State University Comprehensive Cancer Center.