Clofarabine for Langerhans in Pedi

If you are willing to participate in this research study you will be asked to undergo some
screening test or procedure to find out if you are eligible. Many of these tests and
procedures are likely to be part of regular care and may be done even if it turns out that
you do not take part in the research study. If you have had some of these tests or
procedures recently, they may or may not have to be repeated. These tests and procedures
include the following: a medical history, performance status, blood tests, assessment of
disease and pregnancy test. If these tests show that you are eligible to participate in the
research study, you will begin the study treatment. If you do not meet the eligibility
criteria, you will not be able to participate in this research study. After confirming
eligibility you will also have a bone marrow test, electrocardiogram and urinalysis.

You will receive a maximum of 6 cycles of study treatment. Each treatment cycle will last
approximately 4 weeks. In each cycle, you will receive the study drug clofarabine daily on
the first 5 days (days 1 to 5) and rest for the remaining days. Clofarabine will be
administered into the vein (IV) over two hours in the clinic or in the hospital. If you have
high-risk disease, the dose of clofarabine will be higher during the first two cycles.

Before the start of each cycle, and at the end of your therapy, you will have a physical
exam and you will be asked questions about your general health and specific questions about
any problems that you are having and any medications you are taking. You will also have
blood and urine tests done to monitor organ functions. You will also undergo an assessment
of your disease by x-ray, CT scan, MRI or PET or bone scans, which wil be performed every
two cycles and at the end of study treatment.

After the final dose of the study drug there will be a follow up period. Once every three
months for the first year, twice yearly for the second and third years, and then annually,
you will have a physical exam and be asked questions about your general health. You will
also have blood and urine tests performed.

Twice yearly for the first three years, x-ray, CT scan, MRI, PET, and/or bone scans will be
repeated if your doctor feels they are necessary.

Inclusion Criteria:

- Have failed first line treatment with prednisone and vinblastine

- Clinical evidence of involvement of hematopoietic system, liver or spleen

- Have failed salvage treatment with cladribine/cytarabine or are not considered to be
eligible for such treatment

- Willing to use effective contraception during study and for six months after study
treatment

- Adequate marrow and organ function

Exclusion Criteria:

- Pregnant or breastfeeding

- Have received chemotherapy or radiotherapy within 2 weeks of study entry

- Have not recovered from adverse events due to previously administered agents

- Receiving other study agents

- Taking drugs with known renal toxicity

- Use of alternative medicine during study treatment

- Uncontrolled intercurrent illness

- History of a different malignancy except if disease-free for at least five years or
within five years for cervical cancer in situ and basal and squamous cell carcinoma
of the skin

- Known to be HIV positive on antiretroviral therapy