Bone Marrow Transplantation, (1999) 23, 977–981 1999 Stockton Press All rights reserved 0268–3369/99 $12.00 http://www.stockton-press.co.uk/bmt Thiotepa, busulfan and cyclophosphamide as a preparative regimen for allogeneic transplantation for advanced chronic myelogenous leukemia D Przepiorka1, I Khouri1, P Thall2, R Mehra1, M-S Lee3, C Ippoliti1, S Giralt1, J Gajewski1, K van Besien1, B Andersson1,MKo¨rbling1, AB Deisseroth1 and R Champlin1 Departments of 1Blood and Marrow Transplantation, 2Biomathematics and 3Laboratory Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA Summary: blast crisis and 15–40% for transplantation in accelerated or second chronic phase.1–7 Busulfan-based preparative Thirty-six adults with chronic myelogenous leukemia regimens have been favored by some for CML as a result (CML) in second or greater chronic phase, accelerated of the potent anti-myeloid activity and ease of adminis- phase, or blast crisis underwent marrow or blood stem tration of busulfan, and results with the busulfan–cyclopho- cell transplantation from an HLA-matched sibling using sphamide regimen are similar to those achieved with cyclo- high-dose thiotepa, busulfan and cyclophosphamide phosphamide and total body irradiation for patients with (TBC) as the preparative regimen. All evaluable advanced CML.8 N,NЈ,NЈ-triethylenethiophosphoramide patients engrafted and had complete donor chimerism. (thiotepa) is a highly myelosuppressive alkylating agent One patient failed to clear meningeal leukemia, and one that lacks overlapping toxicities with busulfan or cyclopho- patient had one of 30 metaphases positive for the Phila- sphamide.9 We evaluated the combination of thiotepa with delphia chromosome at 2 months post transplant. The busulfan and cyclophosphamide as a preparative regimen remainder of the patients studied had eradication of to determine if addition of a third alkylating agent would CML documented by cytogenetics and/or Southern blot improve outcome without increased toxicity. The maximal for BCR gene rearrangement, and 13 of 15 patients tolerated dose of this combination was previously identified studied became negative for the BCR gene rearrange- in a phase I study.10 Here we report the results using this ment by polymerase chain reaction. Three-year relapse novel regimen for transplantation of patients with advanced rate is 42% (95% CI, 19–64%). The relapse rate was CML from HLA-identical donors. significantly lower for patients transplanted without blast crisis (9% vs 100%, P Ͻ 0.001). Eight (22%, 95% CI, 10–39%) patients had severe or fatal veno-occlusive Materials and methods disease (VOD). Elevated liver enzymes within 1 month prior to transplantation and transplantation using mar- Eligibility criteria row were significantly associated with the occurrence of VOD. Three-year survival is 28% (95% CI, 13–43%). From May 1991 to January 1996, patients with CML past Survival was significantly higher for patients trans- first chronic phase having a t(9;22) documented by cyto- planted without blast crisis (45% vs 0%, P = 0.01). TBC genetics or Southern blot for rearrangement of the BCR is an effective preparative regimen for CML in acceler- gene were eligible for treatment on consecutive phase I– ated phase but not refractory blast crisis, and it should II studies of thiotepa, busulfan and cyclophosphamide as be used with caution in patients with prior hepatopathy preparative regimen. Other requirements included age 15– who have an increased risk of severe VOD. 55 years, Zubrod performance status 0–2, adequate organ Keywords: allogeneic bone marrow transplantation; function, and an HLA-matched related donor.10,11 Protocols chronic myelogenous leukemia; thiotepa; busulfan were approved by the institutional review board of the MD Anderson Cancer Center, and written informed consent was obtained from all patients and donors. Advanced phase of disease is a strong predictor of poor outcome after HLA-identical marrow transplantation for Treatment 1 chronic myelogenous leukemia (CML). Long-term sur- The preparative regimen consisted of thiotepa 150– vival is reported to be 0–25% for patients transplanted in 250 mg/m2/day i.v. on days Ϫ9, Ϫ8 and Ϫ7, busulfan 1 mg/kg orally every 6 h on days Ϫ6, Ϫ5 and Ϫ4 (for a total of 12 doses), and cyclophosphamide 60 mg/kg/day i.v. on Correspondence: Dr D Przepiorka, Baylor College of Medicine, Center Ϫ Ϫ for Cell and Gene Therapy, 1102 Bates St, Suite 1100, Houston, TX days 3 and 2 (TBC) with precautions and dose adjust- 10,11 77030, USA ments as described previously. Marrow or blood stem Received 15 July 1998; accepted 19 December 1998 cells were collected as reported,10,11 and T cell depletion TBC for advanced CML D Przepiorka et al 978 was not used. Graft-versus-host disease (GVHD) prophy- intervals for proportions were based on the binomial laxis consisted of tacrolimus (FK506) or cyclosporine distribution. (CsA) with methylprednisolone, methotrexate, or immuno- toxin.10,11 Standard post-transplant care was provided. Thirty-four patients received filgrastim post transplant to Results accelerate neutrophil recovery. Patient characteristics Monitoring post transplant Thirty-six adults were transplanted (Table 1). Twenty had clinical signs of accelerated disease, two were in у2nd Patients were reviewed by one of the study collaborators chronic phase, five were in lymphoid blast crisis, and nine at least weekly to day 100 and less frequently thereafter. were in myeloid blast crisis. Thirteen of 15 patients treated Regimen-related toxicity was scored using the system of with induction chemotherapy were refractory, and two had Bearman et al12 except that death occurring after day 28 relapsed after allogeneic transplantation using a TBI-based due to regimen-related toxicity was still considered grade preparative regimen. 4. Monitoring for idiopathic interstitial pneumonitis, hemorrhagic cystitis and VOD continued to day 100. GVHD was graded according to the consensus criteria.13 Engraftment and GVHD Marrow biopsies and aspirates were examined at 1, 3, 6, All patients who survived at least 28 days engrafted. The 12, 18 and 24 months after transplantation and annually neutrophil count exceeded 0.5 × 109/l and 1.0 × 109/l at a thereafter. Hematopoietic chimerism was evaluated by median of 10 (range, 8–24) days and 11 (range, 9–27) days restriction fragment length polymorphisms (RFLP). post transplant, respectively. The platelet count exceeded Residual disease was evaluated by conventional cytogen- 20 × 109/l and 50 × 109/l at a median of 19 (9–100+) days etics, Southern blot hybridization for a BCR gene and 24 (10–100+) days post transplant, respectively. Com- rearrangement, and, in some cases, by polymerase chain plete chimerism was found by RFLP analysis in 17 of 20 reaction (PCR) for the bcr-abl transcript.14 patients tested. One patient had mixed chimerism transi- Definitions Table 1 Patient and donor characteristics The criteria for blast crisis were у30% blasts in the marrow or blood, or any extramedullary collections of blasts, and Number of patients 36 the criteria for accelerated phase included у10% blasts in Median age 44 years (range) (20–55 years) marrow or blood; Ն20% basophils and eosinophils in mar- Patient sex row or blood; cytopenia unrelated to therapy; and leuko- Male/female 21/15 cytosis, thrombocytosis, adenopathy, splenomegaly or bone Disease status pain unresponsive to therapy. Patients with cytogenetic CP у 2, AP/BC 22/14 clonal evolution and no clinical evidence of accelerated Cytogenetics phase were not eligible for these protocols. Neutrophil High risk/Standard risk 16/20 recovery was defined as the first of 3 consecutive days that Prior treatment the absolute neutrophil count exceeded the target value, and Busulfan 6 platelet recovery was defined as the day that the platelet Hydroxyurea 28 count exceeded the target value with no platelet trans- Interferon 13 Interferon + other 11 fusions the following week. After transplantation, obser- Homoharringtonine 6 vation of the Philadelphia chromosome in two or more con- Induction chemotherapy 15 secutive studies without abnormalities in the blood counts Allogeneic transplantation 2 was considered a cytogenetic relapse. A white blood cell Resistant to therapy 12 9 count greater than 10 × 10 /l with cytogenetic or molecular Thiotepa dose level evidence of the Philadelphia chromosome but less than 5% 150 mg/m2 day 3 blasts and no extramedullary disease was considered a hem- 200 mg/m2 day 4 2 atologic relapse in chronic phase. High-risk cytogenetics 250 mg/m day 29 include variant Ph, double Ph, +8, and 3p abnormalities.15 Transplant Marrow/Blood stem cells 22/14 GVHD prophylaxis Statistical analyses Tacrolimus-based 8 Cyclosporine-based 28 At time of analysis, median time from transplantation for Median donor age 44 years all patients was 4.8 years (range, 2.4–7.1 years). Minimum (range) (14–65 years) follow-up for survivors was 3 years. Categorical data were Donor sex compared using the Fisher exact test. The actuarial risks Male/Female 20/16 of GVHD, relapse, survival and treatment-related mortality Patient–donor pair sex-mismatched 11 were estimated according to Kaplan and Meier, and the Patient–donor pair CMV-seronegative 0 logrank test was used to make comparisons. Confidence TBC for advanced CML D Przepiorka et al 979 ently at 3 months post transplant and remains in remission 42% (95% CI, 19–64%), and there were no cytogenetic 40 months post transplant, and two patients had mixed relapses without clinical evidence of recurrence. The risk chimerism within 3 months prior to hematologic relapse. of relapse correlated with phase of disease but not with type Grades 2–4 GVHD occurred in 49% (95%CI, 31–67%), of transplant, age or cytogenetic risk group (Table 3). and grades 3–4 GVHD in 21% (95% CI, 7–35%). Seventy- five percent of the patients survived at least 100 days, and Survival the incidence of chronic GVHD in these patients was 83% (95% CI, 63–100%).