Fractionated busulfan myeloablative conditioning improves survival in older patients with acute myeloid leukemia and myelodysplastic syndrome.

BACKGROUND: A myeloablative conditioning regimen can be safely given to older patients and those with comorbidities without increasing nonrelapse mortality (NRM) by fractionating the dose of intravenous busulfan. How this approach compares in efficacy with traditional, nonfractionated, lower dose regimens is unknown. METHODS: Outcomes were compared in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome who received either myeloablative, fractionated busulfan (f-Bu) dosed to achieve an area under the curve of 20,000 µmol per minute (f-Bu20K) over 2 weeks (n = 84) or a standard, nonfractionated, lower busulfan dose regimen of 16,000 µmol per minute (Bu16K) over 4 days (n = 78). Both groups also received fludarabine 40 mg/m2 intravenously for 4 days. Graft-versus-host disease prophylaxis was tacrolimus and methotrexate. Patients in the Bu16K group who had unrelated donors also received antithymocyte globulin. The primary endpoint was progression-free survival. RESULTS: Roughly one-half of the patients were aged >65 years, approximately 40% had poor-risk cytogenetics, approximately 40% of those with AML were not in complete remission, and approximately 40% had a comorbidity index >3. At 2 years, progression-free survival was significantly improved in the f-Bu20K group compared with the Bu16K group (45% vs 24%, respectively; hazard ratio [HR], 0.6; 95% CI, 0.4-0.8; P = .004). This was because of a significant reduction in progression (34% vs 59%, respectively; HR, 0.5; 95% CI, 0.3-0.8; P = .003) without any increase in NRM (21% vs 15%, respectively; HR, 1.4; 95% CI, 0.7-3; P = .3), which resulted in improved overall survival (51% vs 31%, respectively; HR, 0.6; 95% CI, 0.3-0.9; P = .01). CONCLUSIONS: A myeloablative, fractionated busulfan regimen reduces relapse and improves survival without increasing NRM in older patients with AML and myelodysplastic syndrome.

Clofarabine Plus Busulfan is an Effective Conditioning Regimen for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acute Lymphoblastic Leukemia: Long-Term Study Results.

We investigated the long-term safety and disease control data obtained with i.v. busulfan (Bu) combined with clofarabine (Clo) in patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (HSCT). A total of 107 patients, median age 38 years (range, 19 to 64 years) received a matched sibling donor (n = 52) or matched unrelated donor (n = 55) transplant for ALL in first complete remission (n = 62), second complete remission (n = 28), or more advanced disease (n = 17). Nearly one-half of the patients had a high-risk cytogenetic profile as defined by the presence of t(9;22) (n = 34), t(4;11) (n = 4), or complex cytogenetics (n = 7). Clo 40 mg/m2 was given once daily, with each dose followed by pharmacokinetically dosed Bu infused over 3 hours daily for 4 days, followed by hematopoietic cell infusion after 2 days of rest. The Bu dose was based on the drug clearance as determined by a test Bu dose of 32 mg/m2. The target daily area under the curve was 5500 µmol/min for patients aged <60 years and 4000 µmol/min for patients aged >59 years. With a median follow-up of 3.3 years among surviving patients (range, 1 to 5.8 years), the 2-year progression-free survival (PFS) for patients undergoing HSCT in first complete remission (CR1), second complete remission (CR2), or more advanced disease was 62%, 34%, and 35%, respectively. The regimen was well tolerated, with nonrelapse mortality (NRM) of 10% at 100 days and 31% at 2 years post-HSCT. The incidence of grade II-IV and III-IV acute graft-versus-host disease (GVHD) was 35% and 10%, respectively; 18% patients developed extensive chronic GVHD. The 2-year overall survival (OS) for patients undergoing HSCT in CR1, CR2, or more advanced disease was 70%, 57%, and 35%, respectively. Among 11 patients aged >59 years treated with reduced-dose Bu in CR1 (n = 7) or CR2 (n = 4), 4 remain alive and disease-free, with a median follow-up of 2.6 years (range, 2 to 4.7 years). Only the presence of minimal residual disease at the time of transplantation was associated with significantly worse PFS and OS in multivariate analysis. Our data indicate that the Clo-Bu combination provides effective disease control while maintaining a favorable safety profile. OS and NRM rates compare favorably with those for traditional myeloablative total body irradiation-based conditioning regimens.

Autologous stem cell transplantation for refractory or poor-risk relapsed Hodgkin's lymphoma: effect of the specific high-dose chemotherapy regimen on outcome.

More active high-dose chemotherapy (HDC) regimens are needed for refractory Hodgkin's lymphoma (HL). We report a cohort analysis of 180 consecutive patients with primary refractory or poor-risk relapsed HL treated with busulfan-melphalan (Bu-Mel) (n = 39), gemcitabine-busulfan-melphalan (Gem-Bu-Mel) (n = 84), or BEAM (BCNU, etoposide, ara-C, melphalan; n = 57) between 2005 and 2010. Their pre-HDC positron emission tomography (PET) scans were interpreted prospectively. Despite more prevalent poor-risk features in the Gem-Bu-Mel cohort, such as PET-positive tumors at HDC, tumors growing at HDC, extranodal disease, or bulky tumors at prior relapse, this cohort had improved outcomes compared with the Bu-Mel and BEAM cohorts, with event-free survival (EFS) rates of 57%, 33%, and 39%, respectively (P = .01), at median follow-up of the whole population of 36 months (range, 3 to 72). Their respective overall survival (OS) rates were, respectively, 82%, 52%, and 59% (P = .04). Secondary acute myelogenous leukemia was seen in 5 patients after BEAM but was not seen in Gem-Bu-Mel and Bu-Mel cohorts (P = .004). Multivariate analyses showed independent adverse effects of an HDC regimen different from Gem-Bu-Mel (hazard ratio [HR] for EFS = 2.3, P = .0008; HR for OS = 2.7, P = .0005), positive PET at HDC (HR for EFS = 2.2, P = .004, HR for OS = 3.1, P = .0001), and >1 previous salvage line (HR for EFS = 1.9, P = .008, HR for OS = 1.8, P = .07). Gem-Bu-Mel improved outcomes in this cohort analysis of patients with refractory/poor-risk relapsed HL and merits evaluation in randomized phase III trials.

High-dose infusional gemcitabine combined with busulfan and melphalan with autologous stem-cell transplantation in patients with refractory lymphoid malignancies.

We developed a new high-dose combination of infusional gemcitabine with busulfan and melphalan for lymphoid tumors. Gemcitabine dose was escalated by extending infusions at a fixed rate of 10 mg/m(2)/min in sequential cohorts, in daily, 3-dose or 2-dose schedules. Each gemcitabine dose immediately preceded busulfan (adjusted targeting area under the curve 4,000 µM/min(-1)/day × 4 days) or melphalan (60 mg/m(2)/day × 2 days). We enrolled 133 patients (80 Hodgkin lymphoma [HL], 46 non-Hodgkin lymphoma [NHL], 7 myeloma), median 3 prior regimens; primary refractory disease in 63% HL/45% NHL and positron emission tomography positive tumors at transplantation in 50% patients. Two patients died from early posttransplantation infections. The major toxicity was mucositis. The daily and 3-dose schedules caused substantial cutaneous toxicity. In contrast, the 2-dose schedule was better tolerated, which allowed us to extend the infusions from 15 to 270 minutes. Pretransplantation values of C-reactive protein, B-type natriuretic peptide, ferritin, or haptoglobin did not correlate with toxicity. Overall response and complete response rates were 87%/62% (HL), 100%/69% B large-cell lymphoma (B-LCL), 66%/66% (T-NHL), and 71%/57% (myeloma). At median follow-up of 24 months (range, 3-63 months), the event-free/overall survival rates were 54%/72% (HL), 60%/89% (B-LCL), 70%/70% (T-NHL), and 43%/43% (myeloma). In conclusion, gemcitabine/busulfan/melphalan is a feasible regimen with substantial activity against a range of lymphoid malignancies. This regimen merits further evaluation in phase II and III trials.

Eltrombopag for Post-Transplantation Thrombocytopenia: Results of Phase II Randomized, Double-Blind, Placebo-Controlled Trial.

Prolonged thrombocytopenia occurs in up to 37% of patients after hematopoietic stem cell transplantation (HSCT) and is associated with adverse prognosis and increased risk of bleeding. Eltrombopag, a thrombopoietin receptor agonist, can increase platelet counts in thrombocytopenic patients. We conducted a phase II study, adaptively randomizing patients at ≥35 days post-HSCT to receive placebo or eltrombopag at a platelet count ≤20,000/µL for 7 days or platelet transfusion-dependent and a neutrophil count ≥1500/µL. Sixty patients were randomized to eltrombopag (n = 42) or placebo (n = 18) and received at least 1 dose. Fifteen patients (36%) in the eltrombopag arm achieved a platelet count of ≥30,000/µL, compared with 5 patients (28%) in the placebo arm, with a posterior probability of 0.75. (The protocol required this probability to be >0.975 to declare a winner; thus, the results are inconclusive.) However, 9 patients (21%) in the eltrombopag arm achieved a platelet count of ≥50,000/µL, compared with no patients in the placebo arm (P = .046). The overall survival, progression-free survival, relapse rate, and nonrelapse mortality were similar in the 2 arms. In conclusion, compared with placebo, treatment with eltrombopag led to a higher percentage of patients achieving a platelet count of ≥50,000/µL in patients with persistent thrombocytopenia after HSCT.

Conditioning with busulfan plus melphalan versus melphalan alone before autologous haemopoietic cell transplantation for multiple myeloma: an open-label, randomised, phase 3 trial.

BACKGROUND: Retrospective studies suggest that conditioning therapy with busulfan plus melphalan could result in longer progression-free survival compared with melphalan alone in patients with multiple myeloma undergoing autologous haemopoietic cell transplantation (auto-HCT). We aimed to test this hypothesis in a randomised trial. METHODS: The primary objective of the study was to compare progression-free survival with conditioning of busulfan plus melphalan with melphalan alone in patients with multiple myeloma. Patients with newly diagnosed multiple myeloma who were eligible for cell transplantation, aged 70 years or younger, with at least stable disease, were randomly assigned (1:1) to treatment. Patients received either busulfan plus melphalan, with a test dose of busulfan 32 mg/m2 followed by pharmacokinetically adjusted doses on days -7, -6, -5, and -4 to achieve a target daily area under the curve (AUC) of 5000 mmol-minute and melphalan 70 mg/m2 per day on days -2 and -1 (total melphalan dose 140 mg/m2), or a melphalan dose of 200 mg/m2 on day -2. Randomisation was performed via a Clinical Trial Conduct Website at the University of Texas MD Anderson Cancer Center. The accrual is complete and final results are presented here. The study is registered with ClinicalTrials.gov, number NCT01413178. FINDINGS: Between Oct 12, 2011, and March 22, 2017, 205 patients were assessed for eligibility and randomly assigned to treatment. The primary analysis of progression-free survival was measured in 202 patients who received treatment: 104 patients in the busulfan plus melphalan group and 98 patients in the melphalan alone group. 90 days after auto-HCT, 102 (98%) of 104 patients given busulfan plus melphalan and 95 (97%) of 98 patients given melphalan alone achieved partial response or better. The median follow-up in the busulfan plus melphalan group was 22·6 months (IQR 15·2-47·1) and 20·2 months (IQR 8·8-46·6) in the melphalan alone group. Median progression-free survival was 64·7 months (32·9-64·7) with busulfan plus melphalan versus 43·5 months (19·9-not estimated) with melphalan alone (hazard ratio 0·53 [95% CI 0·30-0·91]; p=0·022). There were no treatment-related deaths by day 100 in either group. Grade 2-3 mucositis was observed in 77 (74%) of 104 patients in the busulfan plus melphalan group versus 14 (14%) of 98 patients in the melphalan alone group. INTERPRETATION: These findings, if confirmed in other ongoing studies, suggest that busulfan plus melphalan could replace melphalan alone as the conditioning regimen for auto-HCT in patients with newly diagnosed myeloma. FUNDING: This study was funded in part by the National Institutes of Health (NIH) through MD Anderson's Cancer Center Support Grant (CA016672).