Cohorts of 3-6 patients each receive escalating doses of recombinant human thrombopoietin IV on days 4, 6, 8, 10, and 12 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which fewer than 2 patients experience dose limiting toxicity. After the MTD is determined an additional cohort of patients are treated at this dose level every other day on days 4-20. Patients receive filgrastim (G-CSF) subcutaneously beginning on day 5 and continuing until absolute neutrophil count is greater than 1000/mm3 for 2 consecutive days or day 33.