High-dose chemotherapy with busulphan and cyclophosphamide and bone-marrow transplantation for drug-sensitive malignancies in adults: a preliminary report

Formulation and stability of busulfan for intravenous administration in high-dose chemotherapy

The bifunctional alkylating agent busulfan (Bu) was solubilized in a cosolvent mixture of anhydrous dimethylacetamide (DMA), polyethylene glycol 400 (PEG400), and water at a ratio of 1:2:2 (v/v/v), to achieve a Bu concentration of 3 mg/ml, a preparation that would be suitable for parenteral administration in high-dose chemotherapy preceding bone marrow transplantation. The complete formulation was stable for more than 54 h at room temperature (RT, 22 degrees C). An accelerated stability study of Bu in anhydrous DMA or DMA/PEG400 (1:2) as stock solutions indicated shelf-lives of 191 and 180 days respectively, at RT, and 8.2 and 7.5 years, respectively, at 4 degrees C. Although the complete formulation with Bu was very hypertonic, hemolysis studies indicated that the formulation would be safe for intravenous (i.v.) administration, since it would be rapidly diluted to harmless tonicity levels in the blood. Cytotoxicity studies of the complete formulation in vitro proved that Bu retained its activity when dissolved in the complete vehicle. A preliminary pharmacokinetic study in a rodent model after the i.v. administration of Bu at a dose of 1 mg/kg body weight yielded high plasma concentrations of Bu for at least 5 h after injection.

Combined chemotherapy and granulocyte colony-stimulating factor (G-CSF) mobilise large numbers of peripheral blood progenitor cells in pretreated patients

The aim of this study was to examine the effect of G-CSF given after salvage chemotherapy on the mobilisation of peripheral blood progenitor cells (PBPC) in pretreated patients. Seven patients with relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated with methotrexate, cyclophosphamide, cytarabine, etoposide and dexamethasone. G-CSF was given at a dose of 3.8-7.2 micrograms/kg (1-2 ampoules) daily by subcutaneous injection from the onset of neutropenia (< 1.0 x 10(9)/L). A median of 3 leukaphereses was performed when the white cell count was recovering. The median number of granulocyte-macrophage colony-forming cells (GM-CFC) collected was 99 x 10(4)/kg per leucapheresis (range 19-800) or 260 x 10(4)/kg in total per patient (110-1800). Six patients underwent myeloablative chemotherapy with PBPC rescue. No autologous bone marrow or growth factors post-PBPC infusion were administered. The median duration of severe neutropenia (< 0.5 x 10(9)/L) was 8.5 days (range 5-10) and to recovery of neutrophils post-PBPC infusion was 11.5 days (10-15). Severe thrombocytopenia (< 20 x 10(9)/L) was present for 4 days (range 1-5) and the median number of days post-infusion to platelet-transfusion independence was 9 (6-12). In conclusion, G-CSF combined with chemotherapy mobilised large numbers of PBPC for subsequent autotransplantation in pretreated patients with NHL. A single leukapheresis procedure may be sufficient following this protocol.

High dose busulphan/cyclophosphamide for autologous bone marrow transplantation is associated with minimal non-hemopoietic toxicity

We retrospectively reviewed the regimen-related toxicity associated with busulphan (1 mg/kg orally QID days -7 to -4) and cyclophosphamide (60 mg/kg IV days -3 and -2) (Bu/Cy) chemotherapy in 69 consecutive patients who underwent autologous bone marrow transplantation (ABMT). Twenty-four patients received bone marrow (BM) alone, 22 received BM plus post-transplant granulocyte-colony stimulating factor (G-CSF) and 23 received peripheral blood progenitor cells (PBPC) +/- BM plus post-transplant G-CSF. Toxicity was scored using the criteria of Bearman. Grade II and III toxicities included mucosa (38%), liver (8%), central nervous system (5%), kidney (5%), heart (3%), pericardium (2%), bladder (2%) and lung (2%). There were five treatment related deaths (7%) from pneumonitis (2) and veno-occlusive disease, pulmonary hemorrhage and sepsis (1 each). Post-transplant G-CSF (+/- PBPC) resulted in a trend (p = 0.07) towards a reduction in post-transplant stomatitis, but did not impact on the already low incidence of other organ toxicities. As Bu/Cy for ABMT is associated with minimal non-hemopoietic toxicity, the addition of other cytotoxic agents is justified in an attempt to augment the anti-tumour effect of this conditioning regimen.

Effect of peripheral-blood progenitor cells mobilised by filgrastim (G-CSF) on platelet recovery after high-dose chemotherapy

The haemopoietic growth factor granulocyte colony-stimulating factor (G-CSF; filgrastim) substantially shortens the period of severe neutropenia that follows high-dose chemotherapy and autologous bone-marrow infusion by stimulating granulopoiesis. Filgrastim also increases numbers of circulating progenitor cells. We have studied the ability of filgrastim to mobilise peripheral-blood progenitor cells and assessed their efficacy when infused after chemotherapy on recovery of neutrophil and platelet counts. 17 patients with non-myeloid malignant disorders received filgrastim (12 micrograms/kg daily for 6 days) by continuous subcutaneous infusion. Numbers of granulocyte-macrophage progenitors in peripheral blood increased a median of 58-fold over pretreatment values, and numbers of erythroid progenitors increased a median of 24-fold. Three leucapheresis procedures collected a mean total of 33 (SEM 5.7) x 10(4) granulocyte-macrophage progenitors per kg body weight. After high-dose chemotherapy in 14 of the patients (busulphan and cyclophosphamide), these cells were used to augment autologous bone-marrow rescue and post-transplant filgrastim treatment. Platelet recovery was significantly faster in these patients than in controls who received the same treatment apart from the infusion of peripheral-blood progenitors; the platelet count reached 50 x 10(9)/l a median of 15 days after infusion of haemopoietic cells in the study patients compared with 39 days in controls (p = 0.0006). The accelerated neutrophil recovery associated with filgrastim treatment after chemotherapy was maintained. This method may be widely applicable to aid both neutrophil and platelet recovery after high-dose chemotherapy; it will allow investigation of peripheral-blood progenitor-cell allotransplantation.

The toxicity of busulphan and cyclophosphamide as the preparative regimen for bone marrow transplantation

The toxicity of the conditioning regimen of high dose busulphan (Bu) (16 mg/kg) and cyclophosphamide (Cy) (120 mg/kg) has been compared to cyclophosphamide (Cy) (120 mg/kg) and fractionated total body irradiation (TBI) 12-14 Gy. Since 1985, 67 patients have received conditioning of Bu and Cy for HLA-identical sibling bone marrow transplants. 166 patients have received Cy and TBI since 1981. Veno-occlusive disease of the liver occurred in 19% in the Bu-Cy group and was fatal in 1/12 cases, but only in 1.3% of Cy-TBI group (P less than 0.0005) and was fatal in 1/2. 30% of evaluable patients developed haemorrhagic cystitis in the Bu-Cy group and 14% in the Cy-TBI group (P = 0.008). A multiple logistic regression analysis demonstrated the preparative regimen as the only significant risk factor for the development of veno-occlusive disease or haemorrhagic cystitis. Interstitial pneumonia was diagnosed in 12/56 evaluable patients (21%) in the Bu-Cy group and was fatal in 75%. It occurred in 39/137 evaluable patients (28%) in the Cy-TBI group with a 54% case mortality. Within the Bu-Cy group, the incidence of veno-occlusive disease and haemorrhagic cystitis was similar in chronic myeloid leukaemia (CML) and acute leukaemia (AL) groups, but there was a significant (P = 0.003) incidence of interstitial pneumonia in the CML group 36% as compared to 7% in the AL group. Preparative regimen and age were significant risk factors in the development of interstitial pneumonia in patients with CML. A flexural and acral rash ranging from pigmentation to severe erosion was noted in the Bu-Cy group, but not in the Cy-TBI group. Thus, veno-occlusive disease, haemorrhagic cystitis and cutaneous changes were more common in patients receiving Bu-Cy. Interstitial pneumonia was more common in patients receiving Bu-Cy for CML than for AL.

Effects of recombinant human granulocyte and granulocyte-macrophage colony-stimulating factors on neutrophil function following autologous bone marrow transplantation

Functional activity of peripheral blood neutrophils was assessed in eight patients at 4, 6, 8, 10 and 12 weeks following autologous bone marrow transplantation (ABMT). Functions studied included superoxide generation (O2-) intracellular killing of Staphylococcus aureus, phagocytosis and killing of Candida albicans. Neutrophils were tested following in vitro preincubation with 300 pM granulocyte-macrophage colony-stimulating factor (GM-CSF), 1.2 nM granulocyte colony-stimulating factor (G-CSF) or buffered solution (diluent) as control. Our data indicate that during the early period (weeks 4-6) following ABMT most of the patients exhibited diminished neutrophil oxidative metabolism, defective phagocytosis and killing of C. albicans and reduced capacity to kill S. aureus. In some patients a gradual increase in the functional activity of neutrophils occurred with time. Both GM-CSF and G-CSF induced in vitro amplification of (a) O2- production in response to fmet-leu-phe (FMLP) (b) phagocytosis and killing of C. albicans and (c) killing of S. aureus. This study suggests that GM-CSF and G-CSF may enhance the depressed functional activity of neutrophils following ABMT.

Granulocyte colony-stimulating factor and neutrophil recovery after high-dose chemotherapy and autologous bone marrow transplantation

Granulocyte colony-stimulating factor (G-CSF) was administered by continuous subcutaneous infusion to 15 patients with non-myeloid malignancies treated by high-dose chemotherapy and autologous bone marrow infusion. G-CSF was given at variable dosage based on neutrophil count. Sustained serum levels of G-CSF were achieved. Neutrophil recovery was accelerated in G-CSF treated patients compared with 18 historical controls and exceeded 0.5 x 10(9)/l at a mean of 11 days after marrow infusion compared with 20 days for controls, a significant difference. This reduction led to significantly fewer days of parenteral antibiotic therapy, 11 versus 18 days in controls, and less isolation in reverse-barrier nursing, 10 versus 18 days.