The purpose of this study is to determine how effective, and to what extent, Iressa is in the treatment of acute myelogenous leukemia.

Patients will receive Iressa daily until either disease progression or intolerable toxicity develops. On Day 1 of treatment, a physical exam and bloodwork will be performed. Once weekly for the first 8 weeks, a physical exam and complete blood count with differential will be performed.

For the first year, a physical exam, bloodwork will be performed monthly. Bone marrow biopsies will be performed after the first month of therapy and then every 3 months for the first year. After the first year a physical exam, bloodwork will be performed every 3 months and bone marrow biopsies every 6 months.

Inclusion Criteria:

• Patients must have pathologically documented acute myelogenous leukemia and either not be a candidate for myelosuppressive chemotherapy due to age or comorbid disease; or have relapsed acute myelogenous leukemia or be refractory to standard therapy and not likely to require cytoreductive therapy within 30 days.
• ECOG performance status 0, 1 or 2
• Age > 18 years
• Adequate kidney and hepatic function
• Greater than 4 weeks from any chemotherapy, radiotherapy, immunotherapy, or systemic steroid therapy with the exception of hydroxyurea.
• Greater than 2 months following bone marrow or peripheral blood stem cell transplantation or donor lymphocyte infusion.

Exclusion Criteria:

• Uncontrolled active infection
• Urgent need for cytoreductive chemotherapy, surgery, or radiotherapy
• Current chemotherapy or chemotherapy within the last 4 weeks.
• Pregnancy or nursing mothers
• Infection with HIV