Expression and polymorphism (rs4880) of mitochondrial superoxide dismutase (SOD2) and asparaginase induced hepatotoxicity in adult patients with acute lymphoblastic leukemia.

Asparaginase, which depletes asparagine and glutamine, activates amino-acid stress response. Oxidative stress mediated by excessive reactive oxygen species (ROS) causes enhanced mitochondrial permeabilization and subsequent cell apoptosis and is considered as a plausible mechanism for drug-induced hepatotoxicity, a common toxicity of asparaginase in adults with acute lymphoblastic leukemia (ALL). Studies investigating the pharmacogenetics of asparaginase in ALL are limited and focused on asparaginase-induced allergic reaction common in pediatric patients. Here, we sought to determine a potential association between the variant rs4880 in SOD2 gene, a key mitochondrial enzyme that protects cells against ROS, and hepatotoxicity during asparaginase-based therapy in 224 patients enrolled on CALGB-10102, a treatment trial for adults with ALL. We report that the CC genotype of rs4880 is associated with increased hepatotoxicity following asparaginase-based treatment. Thus, rs4880 likely contributes to asparaginase-induced hepatotoxicity, and functional studies investigating this single-nucleotide polymorphism (SNP) are needed to develop therapeutic approaches that mitigate this toxicity.

Maintenance therapy with decitabine in younger adults with acute myeloid leukemia in first remission: a phase 2 Cancer and Leukemia Group B Study (CALGB 10503).

In this prospective phase 2 clinical trial conducted by Cancer and Leukemia Group B (CALGB, now the Alliance), we studied decitabine as maintenance therapy for younger adults with acute myeloid leukemia (AML) who remained in first complete remission (CR1) following intensive induction and consolidation. Given that decitabine is clinically active in AML and with hypomethylating activity distinct from cytotoxic chemotherapy, we hypothesized that 1 year of maintenance therapy would improve disease-free survival (DFS) for AML patients <60 years, who did not receive allogeneic stem cell transplantation in CR1. After blood count recovery from final consolidation, patients received decitabine at 20 mg/m2 intravenously daily for 4-5 days, every 6 weeks for eight cycles. One hundred and thirty-four patients received decitabine and 85 (63%) had favorable risk AML. The median number of cycles received was 7 (range: 1-8) and the primary reason for discontinuation was relapse. DFS at 1 year and 3 years was 79% and 54%, respectively. These results are similar to the outcomes in the historical control comprising similar patients treated on recent CALGB trials. Thus, maintenance with decitabine provided no benefit overall. Standard use of decitabine maintenance in younger AML patients in CR1 is not warranted. This trial was registered at www.clinicaltrials.gov as NCT00416598.

An Inherited Genetic Variant in CEP72 Promoter Predisposes to Vincristine-Induced Peripheral Neuropathy in Adults With Acute Lymphoblastic Leukemia.

Peripheral neuropathy is a major toxicity of vincristine, yet no strategies exist for identifying adult patients at high-risk. We used a case-control design of 48 adults receiving protocol therapy for acute lymphoblastic leukemia (ALL) who developed vincristine-induced neuropathy (NCI grade 2-4) during treatment, and 48 matched controls who did not develop grade 2-4 neuropathy. Peripheral neuropathy was prospectively graded by National Cancer Institute (NCI) criteria. CEP72 promoter genotype (rs924607) was determined using polymerase chain reaction (PCR)-based single nucleotide polymorphism (SNP) genotyping. Frequency of the CEP72 T/T genotype was higher in cases (31% vs. 10%, P = 0.0221) and the incidence of vincristine-induced neuropathy (grades 2-4) was significantly higher in patients homozygous for the CEP72 T/T genotype. 75% of the 20 patients homozygous for the CEP72 T allele developed grade 2-4 neuropathy, compared to 44% of patients with CEP72 CC or CT genotype (P = 0.0221). The CEP72 polymorphism can identify adults at increased risk of vincristine-induced peripheral neuropathy.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

Quantitative characterization of T-cell repertoire in allogeneic hematopoietic stem cell transplant recipients.

Allogeneic hematopoietic stem cell transplantation (HSCT) is one of curative treatment options for patients with hematologic malignancies. Although GVHD mediated by the donor's T lymphocytes remains the most challenging toxicity of allo-HSCT, graft-versus-leukemia (GVL) effect targeting leukemic cells, has an important role in affecting the overall outcome of patients with AML. Here we comprehensively characterized the TCR repertoire in patients who underwent matched donor or haplo-cord HSCT using next-generation sequencing approach. Our study defines the functional kinetics of each TCRA and TCRB clone, and changes in T-cell diversity (with identification of CDR3 sequences) and the extent of clonal expansion of certain T-cells. Using this approach, our study demonstrates that higher percentage of cord-blood cells at 30 days after transplant was correlated with higher diversity of TCR repertoire, implicating the role of cord-chimerism in enhancing immune recovery. Importantly, we found that GVHD and relapse, exclusive of each other, were correlated with lower TCR repertoire diversity and expansion of certain T-cell clones. Our results highlight novel insights into the balance between GVHD and GVL effect, suggesting that higher diversity early after transplant possibly implies lower risks of both GVHD and relapse following the HSCT transplantation.

A novel clofarabine bridge strategy facilitates allogeneic transplantation in patients with relapsed/refractory leukemia and high-risk myelodysplastic syndromes.

Patients with relapsed/refractory leukemias or advanced myelodysplastic syndrome (MDS) fare poorly following allogeneic hematopoietic cell transplant (HCT). We report prospective phase II study results of 29 patients given clofarabine 30 mg/m(2)/day i.v. × 5 days followed immediately by HCT conditioning while at the cytopenic nadir. A total of 15/29 patients (52%) were cytoreduced according to pre-defined criteria (cellularity <20% and blasts <10%). Marrow cellularity (P<0.0001) and blast% (P=0.03) were reduced. Toxicities were acceptable, with transient hyperbilirubinemia (48%) and gr3-4 infections (10%). In all, 28/29 proceeded to transplant; 27 received ATG or alemtuzumab. Post HCT, 180 day non-relapse mortality (NRM) was 7% (95% confidence interval (CI): 1-21), relapse was 29% (95% CI: 13-46) and OS was 71% (95% CI: 51-85), comparing favorably to published data for high-risk patients. Two-year graft vs host disease incidence was 40% (95% CI: 21-58) and 2 year OS was 31% (95% CI: 14-48). Disease at the nadir correlated with inferior OS after HCT (HR=1.22 for each 10% marrow blasts, 95% CI: 1.02-1.46). For AML/MDS patients, there was a suggestion that successful cytoreduction increased PFS (330 vs 171 days, P=0.3) and OS (375 vs 195 days, P=0.31). Clofarabine used as a bridge to HCT reduces disease burden, is well tolerated, and permits high-risk patients to undergo HCT with acceptable NRM. Late relapses are common; thus, additional strategies should be pursued. NCT-00724009.

Phase I/II multicenter study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of AZD4877 in patients with refractory acute myeloid leukemia.

Eg5 (kinesin spindle protein) is a microtubule motor protein, essential for centrosome separation during mitosis. This Phase I/II, open-label, multicenter, two-part study investigated AZD4877, a potent Eg5 inhibitor, in patients with acute myeloid leukemia. Primary objectives were to determine the maximum tolerated dose (MTD) (part A), assess efficacy (part B) and determine the pharmacokinetic profile (parts A and B). Secondary objectives included assessment of safety and tolerability. AZD4877 was administered at a range of doses (2, 4, 7, 10, 13, 16 and 18 mg/day) as a 1-hour intravenous infusion on three consecutive days of a continuous 2-week schedule. The MTD in part A was defined as 16 mg/day based on dose-limiting stomatitis at 16 and 18 mg/day, hyperbilirubinemia at 16 mg/day and palmar-plantar erythrodysesthesia syndrome at 18 mg/day. Systemic exposure to AZD4877 generally increased with increasing dose whereas half-life was not dose dependent. No evaluable patients experienced a complete remission (CR) or CR with incomplete blood count recovery (CRi), demonstrating no evidence of AZD4877 efficacy in this population. Evidence of monoasters in all but the 4 mg/day dose group provided proof of mechanism for AZD4877. This study was terminated due to lack of efficacy. (ClinicalTrials.gov identifier NCT00486265).

Feasibility of clofarabine cytoreduction before allogeneic transplant conditioning for refractory AML.

To control disease before allogeneic hematopoietic cell transplantation (HCT) for relapsed/refractory AML, we used clofarabine cytoreduction. Seventeen patients received clofarabine 30-40 mg/m(2) i.v. daily for 5 days with plans to initiate conditioning during the nadir, 14 days later. Bone marrow biopsy 12 days after clofarabine showed effective cytoreduction (that is,<20% cellularity with <10% blasts) in 10 of 17 patients (59%). Ineffective cytoreduction correlated with lower PFS (3.8 vs 6.4 months; HR=2.7, 95% CI=1.10-14.29, P=0.035) and OS (5.1 vs 16.6 months; HR=2.5, 95% CI=0.98-12.17, P=0.053). Significant toxicities before HCT, attributable to clofarabine, were grade 1-2 hyperbilirubinemia (18%); grade 1-2 (59%) or grade 3-4 (18%) transaminitis; and grade 1-2 (18%) creatinine elevation. Sixteen patients proceeded to HCT infusion 22 days (median) after initiation of clofarabine. Day 100 and 2-year transplant-related mortality were 6 and 36%. Nine patients relapsed. One year PFS and OS were 25 and 38%, respectively. Two patients are alive in remission at 18 and 52 months. Clofarabine cytoreduction followed by immediate HCT is feasible with acceptable toxicity and TRM. Outcomes for this cohort of patients with refractory AML remain poor and we are studying this approach in a prospective manner.

Outcomes of patients with AML and MDS who relapse or progress after reduced intensity allogeneic hematopoietic cell transplantation.

We describe treatment, outcomes and prognostic factors for patients who relapse following transplantation with a reduced intensity conditioning regimen. Seventy consecutive patients with high-risk myeloid malignancies underwent transplant and 25 (36%) relapsed, a median of 120 days later. The median percentage of bone marrow blasts at relapse was 24, the median donor chimerism was 73% and new karyotypic abnormalities occurred in 8 out of 20 (40%) evaluable patients. Twenty-one patients (84%) received aggressive treatment for relapse, including chemotherapy (60%), second hematopoietic cell transplantation (HCT; 52%) and/or donor lymphocyte infusion (DLI; 12%). Thirteen achieved a complete response (CR) and four remain in CR. Median overall survival (OS) after relapse was 6 months (95% confidence interval=2.7-9.9 months), and actuarial 1 year OS was 24%. Most deaths were due to disease progression (17/20, 85%). We did not observe an advantage for cellular therapy (DLI or second transplant) compared to chemotherapy. Salvage therapy for relapse after reduced intensity HCT is feasible, associated with low treatment-related mortality, and may result in prolonged survival in select patients. Studies exploring the optimal treatment for relapse following reduced intensity HCT are warranted.

Pre-transplant ganciclovir and post transplant high-dose valacyclovir reduce CMV infections after alemtuzumab-based conditioning.

Alemtuzumab (Campath-1H)-based conditioning regimens are effective in preventing GVHD, but are associated with very high rates of cytomegalovirus (CMV) infection, a major limitation to their use. We evaluated 85 patients receiving conditioning with fludarabine 30 mg/m2/day (day -7 to day -3), alemtuzumab 20 mg/day (day -7 to day -3), and melphalan 140 mg/m2 on day -2. The initial patients received post transplant CMV prophylaxis with high-dose acyclovir. A very high incidence of CMV viremia was observed as has been commonly reported after alemtuzumab-based conditioning. Sixty-seven subsequent patients received pre-transplant ganciclovir and high-dose valacyclovir after engraftment. The cumulative incidence of CMV infection in the valacyclovir cohort was 29%. This compared favorably to the cumulative incidence of 53% in patients receiving only acyclovir (P = 0.004) and to literature data. CMV prophylaxis with pre-transplant ganciclovir and high-dose valacyclovir after engraftment appears effective in preventing the excessive incidence of CMV infection after alemtuzumab-based conditioning regimens.

Fludarabine, melphalan, and alemtuzumab conditioning in adults with standard-risk advanced acute myeloid leukemia and myelodysplastic syndrome.

PURPOSE: This prospective phase II study evaluated toxicity, relapse rate, progression-free survival, and overall survival after allogeneic transplantation and conditioning with fludarabine, melphalan, and alemtuzumab in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). PATIENTS AND METHODS: Fifty-two consecutive adults with AML and MDS were enrolled onto the study. Median age was 52 years (range, 17 to 71 years) and the majority of patients had high-risk disease, comorbidities, and/or modest reduction in performance status. Fifty-six percent of patients had unrelated or mismatched related donors. RESULTS: After a median follow-up of 18 months (range, 2 to 34 months), 1-year survival was 48% (95% CI, 34% to 61%), progression-free survival was 38% (95% CI, 25% to 52%), relapse rate was 27% (95% CI, 15% to 40%), and treatment-related mortality was 33% (95% CI, 20% to 46%). The cumulative probability of extensive chronic graft-versus-host disease (GVHD) was only 18% (95% CI, 8% to 40%); extensive chronic GVHD was only observed in recipients of unrelated donor transplants. Performance score and disease status were the major predictors of outcome. High-risk disease (ie, active AML or MDS with > 5% blasts) or even modest decreases in performance status were associated with poor outcomes. Patients with standard-risk leukemia (first or second complete remission) or MDS (< 5% blasts) had excellent outcomes despite unfavorable disease characteristics. CONCLUSION: Fludarabine and melphalan combined with in vivo alemtuzumab is a promising transplantation regimen for patients with AML or MDS and low tumor burden. For patients with active disease, this regimen provides at best modest palliation. Despite a low incidence of GVHD, transplantation is still associated with considerable nonrelapse mortality in patients with decreased performance status.

Impact of disease burden at time of allogeneic stem cell transplantation in adults with acute myeloid leukemia and myelodysplastic syndromes.

The impact of disease burden on the outcome of patients with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplantation (SCT) has not been well defined. Data from several retrospective series suggest that overt leukemia at the time of transplant increases the risk of relapse. We reviewed the outcomes of 68 consecutive adults with AML (n=60) or myelodysplastic syndromes (MDS) (n=8) who received an allogeneic SCT at the University of Chicago between May 1986 and October 2002 to confirm the importance of currently recognized risk factors for overall survival (OS) and progression-free survival (PFS). In addition, we wanted to determine whether quantification of residual disease by blast percentage or cytogenetic abnormalities at the time of SCT was correlated with outcome. AML subtypes based on the FAB classification were as follows: M0=9, M1=9, M2=16, M3=2, M4=16, M5=3, M6=5. Cytogenetic analysis was available from 52 patients. Using standard morphologic criteria, 34 patients were in complete remission (CR) and 34 had visible leukemia present. The majority of donors were HLA-identical siblings (n=55). In all, 56 patients received myeloablative conditioning regimens and 12 received a reduced-intensity, fludarabine-based conditioning regimen. OS and PFS times were 7.1 months (95% CI, 4.8-10.4) and 5.1 months (95% CI, 3.2-7.8), respectively. Median follow-up from SCT was 4.6 years (range, 0.6-17.0) for survivors. In multivariate analysis, the following factors were found to be associated with worse survival: (1) increased percentage of blasts in the bone marrow at the time of SCT, (2) presence of acute graft-versus-host disease, (3) mismatched donor, (4) Zubrod performance score of >/=2, and (5) age >/=45 years. We also found a trend towards improved outcome among patients in cytogenetic remission as compared to those who had residual cytogenetic abnormalities and those in overt relapse. These data support an association between pre-transplant disease burden and poor outcome after SCT.

Regimen-related toxicity after fludarabine-melphalan conditioning: a prospective study of 31 patients with hematologic malignancies.

A total of 31 consecutive patients with hematologic malignancies who were considered poor candidates for TBI underwent allogeneic stem cell transplantation after conditioning with fludarabine and melphalan. A total of 25 matched sibling recipients received fludarabine 25 mg/m(2) x 5 days and melphalan 70 mg/m(2) x 2 days. For unrelated and haploidentical donor recipients, fludarabine was increased to 30 mg/m(2) and ATG 30 mg/kg x 4 days was added. Graft-versus-host disease prophylaxis consisted of tacrolimus and mini methotrexate. All patients engrafted. Regimen-related toxicity was considerable and included mainly renal, hepatic and mucosal toxicity. There were seven regimen-related-deaths including two VOD, two pulmonary, one renal, one cardiac and one mucosal toxicity. One case of fatal pulmonary toxicity death could be attributed to pre-existing pulmonary damage. Progression-free survival at 12 months was 44% (90% CI: 30-58%) for recipients of HLA-identical sibling transplants and 33% (90% CI: 21-45%) for all patients. In conclusion, the fludarabine-melphalan regimen leads to consistent engraftment. The regimen-related toxicity is considerable and cannot be explained solely by patient selection. Cardiac toxicity is emerging as a unique toxicity of this regimen. Despite toxicity, fludarabine-melphalan has considerable activity and leads to durable remission in a proportion of patients.