Inclusion Criteria:

1. Relapsed or refractory acute myeloid leukemia (AML), acute lymphocytic leukemia
(ALL), chronic lymphocytic leukemia (CLL), high risk myelodysplasia (MDS) with an
IPSS score > 2.5, Non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HD) or multiple
myeloma, for which all potentially curative or standard salvage therapy options have
been exhausted.

2. ECOG performance status < 2.

3. Biochemical values within the following range:

- Serum creatinine < 2x upper limit of normal.

- Total bilirubin < 2x upper limit of normal, AST and ALT < 5x upper limit of
normal.

- Normal serum B12 level.

4. Ability to maintain adequate oral intake of medication.

5. Ability to understand and sign informed consent.

6. Toxicity from prior chemotherapy has resolved.

Exclusion Criteria:

1. Uncontrolled systemic infection.

2. Uncontrolled intracurrent illness.

3. Pregnant or breast feeding.

4. CNS disease.

5. Neurologic symptoms related to intracurrent illnesses or unexplained causes.

6. Psychiatric illness that would limit compliance with study.

7. Receiving other systemic chemotherapy, other than hydroxyurea to control circulating
blast counts, within 10 days of study entry. Hydroxyurea is permitted, however the
dose must be stable and unchanged in the 7 days prior to initiation with Clioquinol.

8. Prior therapy with Clioquinol.

9. Use of other investigational antileukemic therapy within two weeks of study entry.

10. Given the neurological side of Clioquinol in the Japanese population, this
population, this trial will exclude patients who have a parent of Oriental or
Japanese origin or who self-identify as Oriental or Japanese (Appendix 9.2).

11. Active ocular problems including visual migraines and glaucoma.

12. Use of oral or intravenous heavy metal supplements including copper, zinc, and
nickel.