Safety Study of CAT-8015 Immunooxin in Patients With HCL With Advance Disease

OUTLINE: Patients receive CAT-8015 IV over 30 minutes on days 1, 3, and 5 followed by rest. Treatment repeats every 4 weeks for up to a total of 10 courses in the absence of dose limiting toxicity, complete response or disease progression. Patients are followed at 1, 3, 6,12,15,18, 21, 24 months following the start of the last treatment cycle. Cohorts of 3-6 patients each will receive escalating doses of recombinant CAT-8015 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose proceeding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. Once the MTD is determined, between16 to 25 new patients will be added to the MTD cohort depending on how well the CAT-8015 is tolerated.