Intensive dose ifosfamide and etoposide with G-CSF for stem cell mobilization in patients with non-Hodgkin's lymphoma

We studied 36 patients with non-Hodgkin's lymphoma to evaluate the stem cell yield following recovery from intensive dose ifosfamide and etoposide given as mobilization chemotherapy. We also assessed the toxicity of the regimen and engraftment kinetics. All patients had intermediate grade lymphoma and had either failed to achieve a complete remission to induction chemotherapy or had relapsed. Patients received ifosfamide 10 g/m2 IV total dose given over 72 hours, etoposide 150 mg/m2 IV every 12 hours for 6 doses and G-CSF 10 microg/kg/d. Thirty-four patients went on to receive high-dose chemotherapy with BEAM or with CVP and BEAM. A median of 2 (1-10) apheresis was required to reach the target CD34+ count of >4 x 10(6)/kg. A median of 13.1 CD34+ cells/kg (4.1-148) was obtained. Toxicity was limited to mucositis in 3 patients, transient confusion and transient rise in liver function tests in 3 and 2 patients respectively. The median time to engraftment was 10 days (8-17) for all the patients undergoing high-dose chemotherapy. The regimen of intensive dose ifosfamide and etoposide along with G-CSF is well tolerated and in this group of patients has lead to successful stem cell harvests and sustained engraftment.

Comparative molecular field analysis-based predictive model of structure-function relationships of polyamine transport inhibitors in L1210 cells

Maintenance of intracellular polyamine concentrations necessary for cell growth and proliferation is regulated in part by an energy-dependent polyamine uptake system. To obtain information on the characteristics of the polyamine uptake system in L1210 leukemia cells, we have applied computational chemistry techniques to the study of relationships between structure and function of 57 polyamine analogues. Ki values of polyamine analogues, derived from competitive inhibition of [3H]spermidine transport into L1210 cells, were chosen as the measure of biological activity. Using comparative molecular field analysis (CoMFA), a model was constructed to relate molecular structure with biological activity. The model was based on 4 monocationic, 8 dicationic, 14 tricationic, and 20 tetracationic polyamine analogues with a range of Ki values for the inhibition of [3H]spermidine uptake of 0.97-521 microM. The CoMFA model successfully predicted the inhibitory potency of 11 polyamines that had not previously been tested for polyamine uptake inhibitory activity. The 11 values predicted were within 33 +/- 62% of the actual Ki values. The test group included aziridinyl diamines, acetylated spermidines, two new oxazolidinonyl spermidines, monoaziridinyl spermidines, and a diaziridinyl spermine. Several of the compounds from this test group have been shown to have anticancer activity in mice. Consistent with the CoMFA model, certain basic functional groups, such as aziridines that have pKa values in the range of 6-7, seem to interact with the polyamine transporter in a cationic form. The results suggest that the CoMFA model is useful in drug design strategies as a predictive tool for the discovery of new anticancer agents that utilize a polyamine transporter for cellular uptake.