Prospective validation of a novel IV busulfan fixed dosing for paediatric patients to improve therapeutic AUC targeting without drug monitoring.

INTRODUCTION: Oral busulfan clearance is age-dependent and children experience a wide variability in plasma exposure. BSA- or age-based dosing is used with therapeutic drug monitoring (TDM) to reduce this variability. PURPOSE: A new intravenous (IV) dosing of busulfan (Bu) based on body weight, designed to improve AUC targeting without TDM and dose-adjustment, was prospectively evaluated. METHOD: Bu was administered as a 2 h IV infusion every 6 h over 4 days (16 administrations). Five dose levels were defined on body weight as follows: 1.0 mg/kg for <9 kg; 1.2 mg/kg for 9 to <16 kg; 1.1 mg/kg for 16-23 kg; 0.95 mg/kg for >23-34 kg; 0.80 mg/kg for >34 kg. Bu treatment was followed by Cyclophosphamide or Melphalan prior to allogeneic or autologous transplantation in 55 children aged 0.3-17.2 years (median 5.6 years). RESULTS: No difference in AUC values was observed between weight strata (mean +/- SD 1248 +/- 205 micromol.min), whereas a significant difference in Bu clearance was demonstrated. This new dosing enabled to achieve a mean exposure comparable to that in adults. At dose 1, 91% of patients achieved the targeted AUC range (900-1500 micromol.min) while no patients were underexposed. At doses 9 and 13, over 75% of patients remained within that target whilst most of the others were slightly above. Successful engraftment was achieved in all patients. In conclusion, from infants to adults this new dosing enabled, without TDM and dose adjustment, to successfully target a therapeutic AUC window.

Autologous hematopoietic stem cell transplantation as salvage treatment for advanced B cell chronic lymphocytic leukemia.

Given the generally poor outcome of advanced B cell chronic lymphocytic leukemia, experimental approaches are warranted, especially for younger patients in whom classical treatments have failed. We therefore conducted a prospective single-center study, using polychemotherapy (ESHAP) to prepare patients for hematopoietic stem cell collection and autologous stem cell transplantation as consolidation therapy. Twenty patients entered the study. An adequate response to ESHAP was obtained in 13 patients, and sufficient stem cells for grafting were obtained in eight of the 12 patients who underwent the collection procedure. Six of these grafted patients are alive in complete clinical remission a median of 30 months after transplantation. It should be noted that we were only able to graft 40% of the patients enrolled in this study, either because a new remission could not be obtained or because not enough hematopoietic stem cells could be collected. This argues for stem cell collection as soon as a first remission is obtained, even if the autograft is done later in the course of the disease.

Intensive chemotherapy with hematopoietic cell transplantation after ESHAP therapy for relapsed or refractory non-Hodgkin's lymphoma. Results of a single-centre study of 65 patients.

This study was designed to assess the results of protracted courses of ESHAP (etoposide, cytarabine, cisplatin, methylprednisolone) therapy followed by intensive chemotherapy and hematopoietic cell transplantation (IC+HCT) for relapsed or refractory non-Hodgkin's lymphoma (NHL). Treatment consisted of 3 cycles of ESHAP; responsive patients (pts) then received 3 more cycles, and IC+HCT was used for pts in maintained partial (PR) or complete (CR) remission after the sixth ESHAP. Sixty-five pts entered the study. At enrollment, 27 pts had bone marrow (BM) and/or central nervous system (CNS) lymphomatous infiltration. Disease status was primary refractory lymphoma in 41 pts (63 %), and relapse in 24 pts (37 %). Results showed that two pts were not evaluable for the therapeutic response because of early treatment-related death. Thirty-nine (62 %) pts entered PR or CR after 3 cycles of ESHAP. Eleven pts subsequently had disease progression. Twenty-eight pts were in persistent CR or PR after 6 cycles of ESHAP. Refractory pts did not show a different response rate to relapsing pts (chi2= 1.73). Five pts were excluded from IC+HCT because of an inadequate graft or treatment-related toxicity. Twenty-three (35 %) pts completed the procedure. Five pts (22 %) relapsed after IC+HCT. The overall survival rate of the 39 responsive pts is 45 % at 60 months, with a median survival time of 30 months. Median survival among the 35 pts in whom second-line chemotherapy failed is 7.1 months, with a 4-year survival rate of 3 %. Despite the poor prognostic features of this group, 45% of pts responding to the first 3 cycles of chemotherapy are in prolonged remission, suggesting that rather than to transplant after just 2 cycles of salvage therapy, pursuing second-line chemotherapy may better discriminate between patients more likely to benefit from a subsequent transplant.

Late CD8+ lymphocytic alveolitis after allogeneic bone marrow transplantation and chronic graft-versus-host disease.

Late-onset interstitial pneumonitis following allogeneic bone marrow transplantation (BMT) is a rare condition usually caused by a variety of infective agents, although in some cases these are idiopathic. We investigated noninfectious late interstitial pneumonitis with lymphocytic alveolitis in seven allogeneic BMT recipients using bronchoalveolar lavage (BAL), lymphocyte phenotyping analysis, CT lung scans, and pulmonary function tests. The results were compared with those of a control group composed of similar patients with no pulmonary symptoms. Of 65 long-term survivors, seven were included in the study. All had chronic graft-versus-host disease (GVHD) and developed interstitial pneumonitis a median of 210 d (range 120 to 445 d) after BMT. BAL revealed lymphocytosis, with an overall expansion of CD8+ subsets (38 to 90%). Lymphocytic alveolitis was not observed in the control group. Pulmonary function tests revealed a restrictive syndrome, and biopsy samples obtained from 2 patients showed interstitial lymphoid infiltration with fibrosis of the alveolar walls. Of the 7 patients, six were cured by starting immunosuppressive drugs or increasing the dosage with a drastic improvement in respiratory symptoms within 1 mo. These findings suggest that CD8+ alveolitis may be observed in late interstitial pneumonitis in allogeneic BMT recipients and may be a pulmonary manifestation of chronic GVHD.