A phase I/II study of multicyclic dose-intensive chemotherapy supported with G-CSF, or G-CSF and haematopoietic progenitor cells in whole blood, in two consecutive cohorts of patients.

We investigated the reconstitutive potential of haematopoietic progenitor cells collected in autologous whole blood during multicycle dose-intensified chemotherapy. Forty patients with metastatic solid tumours were treated with up to six cycles of cisplatin and escalating doses of ifosfamide every 14 days. Cisplatin was administered in 3% sodium chloride over 3 h, followed by ifosfamide over 24 h and mesna over 36 h. The first cohort of patients received granulocyte colony-stimulating factor (G-CSF) days 4-14. Once dose-limiting toxicity was reached in cohort 1, the study continued with a second cohort of patients, in whom, in addition to G-CSF on days 4-14, 500 ml of G-CSF and chemotherapy-'primed' whole blood was collected on day 15, i.e. on day 1 of treatment cycles two to six, before cisplatin administration. This volume of blood was kept unprocessed at 4 degrees C and reinfused 20-24 h after the completion of ifosfamide. In cohort 1, dose-limiting toxicity (DLT) was reached at ifosfamide 6.0 g m(-2) with two out of six of the patients developing neutropenic fever. Although in cohort 2 no neutropenic fever was encountered, neither the frequency nor the duration of grade 4 neutropenia and thrombocytopenia were reduced. Cumulative asthenia resulted in DLT at 7.0 g m(-2). The median number of CD34+ cells in 500 ml of whole blood after the first cycle (i.e. at start of cycle 2) was 1.15 x 10(6) kg(-1). This number was significantly greater after the second cycle (2.06 x 10(6) kg(-1), P = 0.01) and then gradually decreased after cycles three to six. After storing whole blood, the number of CD34+ cells had not decreased (median + 10%). We conclude that the method of combined bone marrow support by G-CSF and haematopoietic progenitor cells in autologous whole blood collected before each cycle of a 2-weekly regimen of cisplatin-ifosfamide does not result in clinically measurable reduced bone marrow toxicity compared with what can be expected by the use of G-CSF alone.