The purpose of this study is to identify the highest tolerated doses in drugs used to treat aggressive leukemia, lymphoma or multiple myeloma not responding to standard chemotherapy treatment. The drugs being used in this study include drugs frequently used in treating such diseases (mitoxantrone and etoposide) as well as a newer drug that has also been shown to be effective (topotecan).

The purpose of this study is to identify the highest tolerated doses in drugs used to treat aggressive leukemia, lymphoma or multiple myeloma not responding to standard chemotherapy treatment. The drugs being used in this study include drugs frequently used in treating such diseases (mitoxantrone and etoposide) as well as a newer drug that has also been shown to be effective (topotecan).

Inclusion Criteria:

Patients in the following disease categories will be considered eligible for this study:

• Any acute leukemia beyond an initial attempt to induce a remission or after relapse
• Chronic Myelogenous Leukemia in Blast Phase
• Refractory Multiple Myeloma
• Refractory non-Hodgkin's and Hodgkin's Lymphoma
• Patients must be more than 14 days beyond prior myelotoxic chemotherapy
• Several other eligibility criteria apply.

Exclusion Criteria:

• None