FAILURE OF A SINGLE-CYCLE OF HIGH-DOSE CYCLOPHOSPHAMIDE FOLLOWED BY INTENSIVE MYELOABLATIVE THERAPY AND AUTOLOGOUS STEM-CELL TRANSPLANTATION TO IMPROVE OUTCOME IN RELAPSED DISEASE

Background. This study attempted to determine the use of a single cycl e of high dose cyclophosphamide (60 mg/kg/day X 2) with (N = 16) and w ithout granulocyte macrophage colony stimulating factor (GM-CSF) (N = 12) followed by intensive treatment and autologous stem cell transplan tation (ASCT) in patients with relapsed disease. Methods. Ten patients with multiple myeloma, eight with non-Hodgkin's lymphoma, three with Hodgkin's disease, six with breast cancer, and one with ovarian cancer were studied. Eighteen patients were in resistant relapse (RR) and 10 had sensitive relapses (SRs). All patients had marrow involvement wit h tumor and had received extensive prior therapy. Results. When respon ses were assessed just before undergoing ASCT, none of the patients ac hieved a complete response (CR). Overall, 17 of 28 patients (61%) achi eved a partial response (PR). Seven of 18 patients with RR achieved PR (39%). All 10 patients with SR achieved a PR. There were three early deaths. Sixteen patients underwent peripheral blood stem cell (PBSC) c ollection. Ten of 16 patients received cyclophosphamide plus GM-CSF, a nd 6 received cyclophosphamide alone. In patients treated with cycloph osphamide plus GM-CSF and cyclophosphamide alone, a median of 5.52 X 1 0(6) CD34+ cells/kg (range, 0.26-30.49) and 5.72 X 10(6) (range, 1.25- 15.66) were collected, respectively. There was no apparent improvement in collection efficiency with GMCSF. Twenty-two of 28 patients procee ded to ASCT irrespective of response, a median of 45 days (range, 21-2 03 days) after cyclophosphamide administration. After transplantation, 11 achieved a CR (50%) and 6 a PR (27%). To date, eight patients are alive (median, 679 days; range, 215-1190 days) and five remain in CR m ore than 6 months (median, 321 days; range, 215-1190 days). All eight surviving patients achieved a PR after high dose cyclophosphamide.