Open Label, Phase II Dosing Study of Ara-C Chemotherapy in Combination With EL625 and Idarubicin in Refractory and Relapsed Acute Myelogenous Leukemia (AML)

This clinical trial is designed to assess the ability of cenersen sodium (EL625) in combination with Idarubicin alone or with Cytarabine to either: (1) induce remissions in patients who have previously failed to go into remission in response to chemotherapy; or (2) provide patents who have relapsed after going into a chemotherapy-induced remission with a longer remission.

Cenersen sodium is one of a new class of drugs called antisense oligonucleotides (oligos). Oligos are designed to block the production of specific proteins and thereby inhibit their function. Cenersen sodium targets p53, a widely studied protein.

In cancer, p53 occurs either in the un-mutated ("normal") or mutated forms. The majority of participants in this trial are expected to have un-mutated p53. Cenersen sodium is anticipated to sensitize cancers with un-mutated p53 to most established cancer therapeutics.

p53 has a pivotal role in protecting the body from cells that have suffered genetic damage and, as a result, do not function properly. The protein first senses the level of the damage and then forces the damaged cell to respond to the damage either by repairing itself or committing suicide. In general, the greater the level of damage the more likely the cellular response will be suicide.

Many cancer therapeutics, including both chemotherapy and radiation, cause the types of genetic damage that activate p53 and, consequently, cause either damage repair or cellular suicide. Laboratory studies suggest that cancer cells have a host of defenses that reduce the chances that these cells will respond to genetic damage by committing suicide. So compared to normal cells, cancer cells are more likely to repair the damage caused by cancer therapeutics while normal cells are more likely to commit suicide. Thus, blocking un-mutated p53 is more likely to prevent repair in cancer cells while preventing suicide in normal cells. This provides the basis for a differential effect of cenersen sodium on cancer cells verses normal cells.