Phase II Study for Patients With Relapsed Primary Central Nervous System Lymphoma

Rationale: The blood brain barrier is made up of tightly packed cells to protect the brain
from toxic materials that might travel up from other parts of the body. However, the blood
brain barrier also blocks the delivery of drugs, including therapies for brain tumors. This
study includes a combination of chemotherapy agents that might have efficacy against
malignant central nervous system lymphoma and a technique called reversible opening of the
blood brain barrier. The technique is experimental and might improve the delivery of
treatments to the disease in the brain. Through this technique, the blood brain barrier is
opened during an angiogram, or blood vessel study of the brain, along with the use of other
substances.

Treatment: Patients in this study will receive the following treatments: rituximab
(Rituxan), carboplatin (Paraplatin), cyclophosphamide (Cytoxan), etoposide phosphate
(Etopophos), and cytarabine (Cytosar-U). A technique called reversible opening of the blood
brain barrier will also be performed in patients. For two successive days each month for 12
to 16 months, patients will be admitted to the hospital to receive study treatments and an
angiogram. The night before the angiogram, patients will receive rituximab through an
intravenous infusion. The next day, an angiogram will be performed with a general anesthetic
and catheter placed in an artery in the groin. The catheter will be directed into the neck
to one of the arteries going to the brain that supplies the tumor area. A sugar
concentration will then be given to open up the blood brain barrier.

During the two days in the hospital, the drugs carboplatin, cyclophosphamide, and etoposide
phosphate will be given to patients. An imaging exam will be performed before opening the
blood brain barrier and during the angiogram to assess the amount of blood brain barrier
opening. At the physician's discretion, patients may undergo chemotherapy without opening
the blood brain barrier due to safety issues. Two weeks after the hospital chemotherapy,
patients will receive the drug cytarabine. This agent will be given into spinal fluid
through a spinal tap or Ommaya reservoir, which is a port that is implanted under the scalp.