Transplantation of autologous peripheral blood progenitor cells procured after high- dose cytarabine-based consolidation chemotherapy for adults with acute.
Leukemia (1997) 11, 1533–1539 1997 Stockton Press All rights reserved 0887-6924/97 $12.00
Transplantation of autologous peripheral blood progenitor cells procured after highdose cytarabine-based consolidation chemotherapy for adults with acute myelogenous leukemia in first remission G Schiller, M Lee, T Miller, M Lill, A Mittal-Henkle, R Paquette, C Sawyers and M Territo Department of Medicine, Division of Hematology/Oncology, Room 42-121 CHS, UCLA School of Medicine, Los Angeles, CA 90095, USA
The purpose of the study was to evaluate the feasibility and efficacy of high-dose cytarabine-anthracycline consolidation chemotherapy followed by autologous transplantation of chemotherapy/rHuG-CSF-mobilized peripheral blood progenitor cells for adult patients with acute myelogenous leukemia in first remission. Fifty-nine consecutive patients (median age 45, range 18–69) with acute myelogenous leukemia in first remission were enrolled on a study of high-dose cytarabinemitoxantrone consolidation chemotherapy used as a method of in vivo purging for the purpose of autologous peripheral blood progenitor cell transplantation. A median of 7 3 108 peripheral blood mononuclear cells/kg were infused 1 day after preparative conditioning with 11.25 Gy total body irradiation and cyclophosphamide (120 mg/kg). Forty-six patients received myeloablative chemo-radiotherapy followed by the infusion of chemotherapy/rHu-G-CSF-mobilized autologous peripheral blood progenitor cells. The median time to both neutrophil and platelet recovery from transplant was 15 days (range, 11–36 and 5–2531 days, respectively). After a median follow-up of 27 months, 31 patients remain alive with 27 in complete remission. Median remission duration for all eligible patients is 12 months, and actuarial leukemia-free survival at 3 years is 42 6 14%. The actuarial risk of relapse is 54 6 15%. Toxicity of autologous peripheral blood progenitor cell transplant included treatmentrelated death in two patients and grade III/IV organ toxicity in six. Advanced age was a negative prognostic factor for leukemia-free survival. Our results demonstrate that autologous transplantation of chemotherapy-mobilized peripheral blood progenitor cells is feasible in an unselected population of adult patients with acute myelogenous leukemia in first remission producing improved leukemia-free survival with minimal toxicity. Keywords: leukemia; transplant; stem cell; autologous consolidation
Introduction Modern dose-intensive consolidation chemotherapy for patients with acute myelogenous leukemia in first remission produces a median remission duration of 12–18 months; only 20–44% of patients survive 5 years free of recurrence.1–7 The mechanism of relapse is proliferation of leukemia cells which survive induction and consolidation therapy. In order to prolong leukemia-free survival, a variety of other post-remission treatment regimens have been evaluated including myelosuppressive maintenance therapy, multiple and prolonged cycles of consolidation, and allogeneic bone marrow transplantation.4,8–12 Allogeneic bone marrow transplantation from a histocompatible HLA-matched sibling donor is available only to a limited group of younger patients.13 Because of a high treatment-related mortality, the probability of survival after allogeneic transplant is similar to that which can be achieved by dose-intensive consolidation chemotherapy alone.10,14–16 Autologous bone marrow transplantation allows for the use of Correspondence to: G Schiller Received 7 March 1997; accepted 5 May 1997
myeloablative preparative conditioning without the high treatment-related morbidity and mortality of allogeneic transplantation and may be applied to a larger, unselected population of adult leukemia patients. Studies of autologous bone marrow transplantation in younger patients have demonstrated leukemia-free survival in the range of 30% to over 50%, with treatment-related mortality of 10–20%.17–21 One potential complication of autologous bone marrow transplantation involves the risk of leukemia cell contamination; techniques such as purging with 5-hydroperoxycyclophosphamide may reduce leukemia cell contamination of the infusate but have contributed to treatment-related morbidity due to prolonged myelosuppression.17,19 Other techniques such as CD34-positive cell selection, utilized in the treatment of multiple myeloma and other marrow-infiltrating malignancies,22 are ineffective for many patients with acute myelogenous leukemia due to a high frequency of CD34 expression. In order to derive the benefits of myeloablative preparative conditioning without the high treatment-related morbidity and mortality of either allogeneic transplantation or purged autologous bone marrow transplantation, we evaluated the long-term effects of high-dose chemo-radiotherapy followed by the infusion of autologous peripheral blood progenitor cells, rather than bone marrow, procured after high-dose consolidation chemotherapy as a form of in vivo purging for transplantation in patients with acute myelogenous leukemia in first complete remission. We also examined the feasibility of transplantation in a representative population of adult leukemia patients not restricted on the basis of younger age or favorable prognostic features and analyzed the effect of major pretreatment characteristics including age, gender, history of preleukemia, and cytogenetics on treatment-related toxicity and leukemia-free survival. Patients and methods Seventy-seven adult patients with newly diagnosed acute myelogenous leukemia were enrolled on the ALP (Acute Leukemia protocol) 5 study conducted by the UCLA School of Medicine from November 1992 to May 1996. Data were analyzed as of 31 March 1997. Median follow-up from the time of remission induction for surviving patients eligible for consolidation is 29 months (range, 10–52 months). This study design was approved by the UCLA Human Subject Protection Committee and all patients provided written informed consent to participate. The diagnosis of acute myelogenous leukemia was made according to French–American–British (FAB) criteria.23 De novo acute myelogenous leukemia was defined if no documented hematologic abnormality was identified more than 2 months before diagnosis.3 Preleukemia was defined as ineffective hematopoiesis documented more than 2 months before the diagnosis of acute myelogenous leukemia by either an abnormal bone marrow evaluation or an otherwise unex-
Transplantation of PBPC after high-dose chemotherapy G Schiller et al
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plained peripheral blood cytopenia.3,10 Patients with leukemia secondary to treatment for another malignancy were not eligible. Karyotype was classified as follows: (1) normal, ie diploid; (2) abnormal but favorable, ie t(8;21), or abnormalities of 16q; (3) abnormal and unfavorable, ie trisomy 8, abnormalities of chromosomes 5 and/or 7, any abnormality of chromosome 11, multiple (>3 abnormalities) or complex translocation; and (4) abnormal all others.3 Patients with acute promyelocytic leukemia with or without t(15;17) were not eligible for this study. Seventy-seven patients received induction chemotherapy consisting of cytarabine, 100–200 mg/m2 by continuous infusion for 5–7 days and idarubicin 10– 13 mg/m2/day ×3 (70 patients) or daunorubicin, 45– 60 mg/m2/day by intravenous bolus for 3 days (seven patients). Patients received a second course of induction chemotherapy on or after day 21 if residual acute leukemia was found in blood or bone marrow. Complete hematologic remission was defined by the criteria of Ellison et al.24 Sixty-three patients received high-dose cytarabine-based consolidation which was administered in a single course begun a median of 4 weeks after achieving complete remission. Consolidation chemotherapy consisted of highdose cytarabine 2 g/m2 administered as a 2-h i.v. infusion every 12 h for 4 days and mitoxantrone 10 mg/m2 by i.v. bolus/day for 3 days. Human recombinant G-CSF was administered at 5 mg/kg subcutaneously or i.v. or over 30 min beginning 1 day following completion of consolidation and continued until the completion of stem cell leukapheresis. Fifty-nine patients who achieved first complete remission were eligible for consolidation chemotherapy and autologous peripheral blood progenitor cell transplant on the basis of age ,70, and no organ dysfunction. Forty-six eligible patients underwent autologous stem cell transplantation after preparative conditioning with 11.25 Gy total body irradiation given in five fractions over 2.5 days and cyclophosphamide, 60 mg/kg/day by i.v. infusion over 1 h daily for 2 days. Patients received mesna, 60 mg/kg/day by continuous i.v. infusion at the start of cyclophosphamide and continued for 24 h after the last dose. After completion of transplantation, no maintenance therapy or other antileukemia therapy was administered until relapse. Toxicity was scored according to standard criteria.25
Progenitor cell collection and processing Progenitor cell apheresis was begun after an absolute neutrophil count of .1500 mm−3 was achieved during the recovery phase from consolidation therapy. Continuous-flow leukapheresis was performed daily on weekdays with a Cobe Spectra (Cobe, Lakewood, CO, USA) until a total nucleated cell count of >3 × 108/kg and/or CD34 cell count >1 × 106/kg was obtained. Blood volume processed per run was 10 l at a flow rate of 50–70 ml/min. Platelet and erythrocyte fractions were reinfused continuously. The final apheresis product was centrifuged at 400 g concentrated to 108 cells/mm3, and cooled to 4°C. Cytogenetics were analyzed on an aliquot of the leukapheresis collection in all patients undergoing progenitor cell procurement by taking 0.01–0.03 ml of the stem cell suspension sample and placing it directly into flasks containing 10 ml RPMI 1640 culture medium supplemented with 1 ml cell growth factor.26 After remaining in culture for 24–48 h, two drops of ethidium bromide (0.01 mg/ml) were added to each flask for 30 min. One drop of colcemid (10 mg/cm3) (Life Technologies, Grand Island, NY, USA) was added for an
additional hour. Cells were then swollen in a hypertonic solution of 0.4% potassium chloride for 15 min and fixed in Carnoy’s fixative. After subsequent centrifugation and washing of cells with fresh fixative the cell suspension was applied to slides, banded with trypsin, and then stained with Giemsa to obtain metaphase analysis.27 The remainder of the stem cell collection was cryopreserved daily in 10% dimethylsulfoxide by control-rate freezing and stored in the gas phase of liquid nitrogen. Cell counts were performed using a Coulter counter (Coulter Electronics, Hialeah, FL, USA). A target mononuclear cell dose of 5 × 108/kg was used as an endpoint for collection. Samples were run on a FACScan flow cytometer (Becton Dickinson, San Jose, CA, USA) and after 1994, CD34-positive cells were defined with histogram analysis using the whole live-cell population.22 A back-up bone marrow was collected in one patient due to a low peripheral blood progenitor cell collection. Results, on the basis of intention to treat from the time of complete remission, were compared to an age-matched control group receiving consolidation chemotherapy only in a study conducted from 1987 to 1992.3,28 Patients achieving remission were assigned to receive two to three courses of intensive consolidation treatment. Consolidation course 1 consisted of high-dose cytarabine, 2 g/m2 i.v. over 1 h every 12 h for eight doses, days 1–4, and mitoxantrone 10– 12 mg/m2/day for days 1–3. Course 2 consisted of mitoxantrone 10–12 mg/m2 for 3 days and etoposide 200 mg/m2/day for 5 days. Course 3 consisted of cytarabine 2 g/m2 over 1 h every 12 h for eight doses, days 1–4, and daunorubicin 45 mg/m2/day for days 1–3. For historical patients >60 years of age, the consolidation chemotherapy dose was reduced to cytarabine 500 mg/m2, mitoxantrone to 7.5 mg/m2, etoposide to 100 mg/m2, and daunorubicin to 30 mg/m2.28 Supportive care for granulocytopenic patients consisted of reverse isolation in single rooms and treatment with oral nonabsorbable antibiotics including nystatin and either norfloxacin or ciprofloxacin. Febrile granulocytopenic patients received imipenem or cefoperazone sulbactam, or other broad-spectrum antibacterial antibiotics.29 Patients with documented or suspected fungal infections were treated with empiric amphotericin B or fluconazole. Random or single donor platelet transfusions were administered to maintain a platelet count >10 × 109/l. Erythrocytes were transfused to maintain an hematocrit >27%.
Statistical analysis The date of diagnosis of AML and the date of remission were defined by the date of the diagnostic bone marrow studies. Patients were analyzed for overall survival as well as leukemia-free survival (LFS) from the time of remission by the product-limit method of Kaplan and Meier.30 Univariate comparisons of patients undergoing induction and consolidation chemotherapy were performed using Fisher’s exact test and the Wilcoxon rank-sum test.31 Summary estimates included survival fractions ± two times the standard error for 95% confidence intervals for median survival time.30,31 Survival curves were compared using the log rank test. Prognostic factors for achieving complete remission were analyzed using logistic regression. Prognostic factors for survival and leukemia-free survival (LFS) were evaluated using the Cox regression analysis. Analyses were performed using the BMDP statistical package.31 P values were two-sided throughout.
Transplantation of PBPC after high-dose chemotherapy G Schiller et al
Results Fifty-nine patients under the age of 70 received consolidation chemotherapy with high-dose cytarabine and rHuG-CSF for the purpose of in vivo purging and procuring autologous progenitor cells for transplantation. The median duration of follow-up for surviving patients from the time of complete remission is 29 months (range, 10–52 months). Patient characteristics at the time of consolidation chemotherapy are described in Table 1. Toxicity of consolidation chemotherapy included serious neurotoxicity due to high-dose cytarabine in one patient and treatment-related death in two due to infection and multiorgan system failure, respectively. Eight patients did not undergo autologous peripheral blood progenitor cell collection due to prolonged infection (two patients), excessive toxicity related to consolidation (one patient), death due to consolidation (two patients) or early relapse (three patients). Five other patients did not undergo transplant due to patient refusal (two patients), lack of insurance coverage and inadequate progenitor cell collection (one patient each); one patient elected to undergo allogeneic bone marrow transplantation. Results of all 59 patients are included in analysis of remission duration, disease-free survival and survival on the basis of intention to treat. A median of four collections (range, 2–15) were required to procure a median of 7 × 108 total mononuclear cells/kg (range, 3–15 × 108/kg). After 1994, CD34-positive cells were measured in the collections from 19 patients; the median number of CD34-positive progenitor cells procured was 5.6 × 106/kg (range, 0.3–30 × 106/kg). After transplantation, the median time to neutrophil .500 mm−3 and untransfused platelet .20 000 mm−3 were 15 days (range, 11–36 days) and 15 days (range, 5–253+ days), respectively. One patient received rHuG-CSF on day +21 following transplant to hasten hematopoietic recovery; he achieved neutrophil recovery 2 days later. Another patient received a backup bone marrow infusion on day +35 for delayed hematologic recovery. Complications related to autologous peripheral
Table 1
ALP5 patient characteristics
No. No. of patients Sex (M/F) Age (median range) Median WBC × 109/l at diagnosis (range) Antecedent hematologic disorder (%) Chromosomal abnormality (yes/no/unknown) Karyotype Normal Abnormal (favorable) Abnormal (unfavorable) Abnormal (other) Unknown No. of patients (years) (age)
