March 22, 2006

Callisto Pharmaceuticals has expanded its ongoing research trial of L-Annamycin, the company's drug candidate to treat adult patients with relapsed or refractory acute lymphocytic leukemia, to a third clinical trial site. The new site to join the Phase I/IIa clinical trial of L-Annamycin is the Roswell Park Cancer Institute in Buffalo, New York.

In previous published animal studies, L-Annamycin has demonstrated that it can kill tumor cells that are resistant to other anthracycline anticancer drugs. In addition, earlier studies have shown that L-Annamycin may have other key advantages over other anthracycline drugs, including a decreased risk of treatment-related cardiomyopathy (inflammation of the heart muscle), a complication associated with this family of anticancer drugs.