TARGEGEN ANNOUNCES INITIATION OF CLINICAL TRIAL OF JAK2 INHIBITOR TG101348 IN MYELOPROLIFERATIVE DISEASE PATIENTS

San Diego, CA – January 31, 2008 – TargeGen, Inc. today announced that the Company has started a multi-center Phase I/II clinical trial of TG101348, an oral, potent, and highly selective inhibitor of JAK2 in patients with myeloproliferative diseases.

The V617F mutation of JAK2 is implicated in the pathogenesis of certain myeloproliferative diseases, including polycythemia vera (PV), essential thrombocytopenia (ET) and primary myelofibrosis (PMF). In preclinical models of myeloproliferative diseases, TG101348, administered orally, was shown to reduce V617F-expressing cell populations in a dose-dependant manner without adversely impacting normal hematopoeisis. The reduction of V617F- expressing cell populations correlated with improved survival and reduced morbidity. There are no currently approved specific therapies for PV, ET and PMF. These disorders are estimated to affect approximately 200,000 patients in the United States and more than twice that total worldwide.

The current clinical trial is being conducted at multiple centers in the USA. The trial is expected to enroll between 40-80 patients. Primary goals of this open label dose escalating protocol include identification of a maximum tolerated dose (MTD), accumulation of safety data, measurement of drug effect on surrogate markers, biomarkers, and presumptive clinical endpoints.