The role of proteinases in the mobilization of hematopoietic progenitor cells (HPCs) after granulocyte colony-stimulating factor (G-CSF) remains unclear. Here we report that genetic loss of the plasminogen activator inhibitor Pai-1 or of the plasmin inhibitor alpha2-antiplasmin increases HPC mobilization in response to G-CSF. Moreover, thrombolytic agents, such as tenecteplase and microplasmin, enhance HPC mobilization in mice and humans. Taken together, these findings identify a novel role for plasmin in augmenting HPC mobilization in response to G-CSF.

Outcomes of unrelated donor cord blood transplantation in 191 hematologic malignancy children (median age, 7.7 years; median weight, 25.9 kg) enrolled between 1999 and 2003 were studied (median follow-up, 27.4 months) in a prospective phase 2 multicenter trial. Human leukocyte antigen (HLA) matching at enrollment was 6/6 (n = 17), 5/6 (n = 58), 4/6 (n = 111), or 3/6 (n = 5) by low-resolution HLA-A, -B, and high-resolution (HR) DRB1. Retrospectively, 179 pairs were HLA typed by HR. The median precryopreservation total nucleated cell (TNC) dose was 5.1 x 10(7) TNC/kg (range, 1.5-23.7) with 3.9 x 10(7) TNC/kg (range, 0.8-22.8) infused. The median time to engraftment (absolute neutrophil count > 500/mm(3) and platelets 50 000/muL) was 27 and 174 days. The cumulative incidence of neutrophil engraftment by day 42 was 79.9% (95% confidence interval [CI], 75.1%-85.2%); acute grades III/IV GVHD by day 100 was 19.5% (95% CI, 13.9%-25.5%); and chronic GVHD at 2 years was 20.8% (95% CI, 14.8%-27.7%). HR matching decreased the probability of severe acute GVHD. The cumulative incidence of relapse at 2 years was 19.9% (95% CI, 14.8%-25.7%). The probabilities of 6-month and 2-year survivals were 67.4% and 49.5%. Unrelated donor cord blood transplantation from partially HLA-mismatched units can cure many children with leukemias. The study was registered at www.clinicaltrials.gov as #NCT00000603.

Patients with cytogenetically normal acute myeloid leukemia (CN-AML) show heterogeneous treatment outcomes. We used gene-expression profiling to develop a gene signature that predicts overall survival (OS) in CN-AML. Based on data from 163 patients treated in the German AMLCG 1999 trial and analyzed on oligonucleotide microarrays, we used supervised principal component analysis to identify 86 probe sets (representing 66 different genes), which correlated with OS, and defined a prognostic score based on this signature. When applied to an independent cohort of 79 CN-AML patients, this continuous score remained a significant predictor for OS (hazard ratio [HR], 1.85; P = .002), event-free survival (HR = 1.73; P = .001), and relapse-free survival (HR = 1.76; P = .025). It kept its prognostic value in multivariate analyses adjusting for age, FLT3 ITD, and NPM1 status. In a validation cohort of 64 CN-AML patients treated on CALGB study 9621, the score also predicted OS (HR = 4.11; P < .001), event-free survival (HR = 2.90; P < .001), and relapse-free survival (HR = 3.14, P < .001) and retained its significance in a multivariate model for OS. In summary, we present a novel gene-expression signature that offers additional prognostic information for patients with CN-AML.

Thalidomide enhances rituximab-mediated, antibody-dependent, cell-mediated cytotoxicity. We therefore conducted a phase 2 study using thalidomide and rituximab in symptomatic Waldenstrom macroglobulinemia (WM) patients naive to either agent. Intended therapy consisted of daily thalidomide (200 mg for 2 weeks, then 400 mg for 50 weeks) and rituximab (375 mg/m(2) per week) dosed on weeks 2 to 5 and 13 to 16. Twenty-five patients were enrolled, 20 of whom were untreated. Responses were complete response (n = 1), partial response (n = 15), and major response (n = 2), for overall and major response rate of 72% and 64%, respectively, on an intent-to-treat basis. Median serum IgM decreased from 3670 to 1590 mg/dL (P < .001), whereas median hematocrit rose from 33.0% to 37.6% (P = .004) at best response. Median time to progression for responders was 38 months. Peripheral neuropathy to thalidomide was the most common adverse event. Among 11 patients experiencing grade 2 or greater neuropathy, 10 resolved to grade 1 or less at a median of 6.7 months. Thalidomide in combination with rituximab is active and produces long-term responses in WM. Lower doses of thalidomide (ie, <or= 200 mg/day) should be considered given the high frequency of treatment-related neuropathy in this patient population. This trial is registered at www.clinicaltrials.gov as #NCT00142116.

This study tested whether donor-derived HIV-specific immune responses could be detected when viral replication was completely suppressed by the continuous administration of highly active antiretroviral therapy (HAART). A regimen of fludarabine and 200 cGy total body irradiation was followed by infusion of allogeneic donor peripheral blood cells and posttransplantation cyclosporine and mycophenolate mofetil. Viral load, lymphocyte counts, and HIV-1-specific CD8(+) cell immune responses were compared before and after hematopoietic cell transplantation (HCT). Uninterrupted administration of HAART was feasible during nonmyeloablative conditioning and after HCT. The HIV RNA remained undetectable and no HIV-associated infections were observed. CD8(+) T-cell responses targeting multiple epitopes were detected before HCT. After HCT a different pattern of donor-derived HIV-specific CTL responses emerged by day +80, presumably primed in vivo. We conclude that allogeneic HCT offers the unique ability to characterize de novo HIV-1-specific immune responses. This clinical trial was registered at ClinicalTrials.gov (identifier: NCT00112593).

Minimal residual disease (MRD) assessment is standard in many hematologic malignancies but is considered investigational in multiple myeloma (MM). We report a prospective analysis of the prognostic importance of MRD detection by multiparameter flow cytometry (MFC) in 295 newly diagnosed MM patients uniformly treated in the GEM2000 protocol VBMCP/VBAD induction plus autologous stem cell transplantation [ASCT]). MRD status by MFC was determined at day 100 after ASCT. Progression-free survival (PFS; median 71 vs 37 months, P < .001) and overall survival (OS; median not reached vs 89 months, P = .002) were longer in patients who were MRD negative versus MRD positive at day 100 after ASCT. Similar prognostic differentiation was seen in 147 patients who achieved immunofixation-negative complete response after ASCT. Moreover, MRD(-) immunofixation-negative (IFx(-)) patients and MRD(-) IFx(+) patients had significantly longer PFS than MRD(+) IFx(-) patients. Multivariate analysis identified MRD status by MFC at day 100 after ASCT as the most important independent prognostic factor for PFS (HR = 3.64, P = .002) and OS (HR = 2.02, P = .02). Our findings demonstrate the clinical importance of MRD evaluation by MFC, and illustrate the need for further refinement of MM re-sponse criteria. This trial is registered at http://clinicaltrials.gov under identifier NCT00560053.

Smoldering multiple myeloma (SMM) is usually followed expectantly without therapy. We conducted a phase 2 trial in 76 eligible patients with SMM, combining thalidomide (THAL, 200 mg/d) with monthly pamidronate. In the first 2 years, THAL dose reduction was required in 86% and drug was discontinued in 50%. Within 4 years, 63% improved, including 25% qualifying for partial response (PR); by then, 34 patients had progressed and 17 required salvage therapy. Unexpectedly, attaining PR status was associated with a shorter time to salvage therapy for disease progression (P < .001), perhaps reflecting greater drug sensitivity of more aggressive disease. Low beta-2-microglobulin levels less than 2 mg/L were independently associated with superior overall and event-free survival. Four-year survival and event-free survival estimates of 91% and 60%, respectively, together with a median postsalvage therapy survival of more than 5 years justify the conduct of a prospective randomized clinical trial to determine the clinical value of preemptive therapy in SMM. Trial registered at http://www.clinicaltrials.gov under identifier NCT00083382.

Interferon-alpha (IFN-alpha) is a nonleukemogenic treatment of polycythemia vera (PV) able to induce cytogenetic remissions. Its use is limited by toxicity, leading to treatment discontinuation in approximately 20% of patients. We completed a phase 2 multicenter study of pegylated IFN-alpha-2a in 40 PV patients. Objectives included evaluation of efficacy, safety, and monitoring of residual disease using JAK2V617F quantification (%V617F). Median follow-up was 31.4 months. At 12 months, all 37 evaluable patients had hematologic response, including 94.6% complete responses (CRs). Only 3 patients (8%) had stopped treatment. After the first year, 35 patients remained in hematologic CR, including 5 who had stopped pegylated IFN-alpha-2a. Sequential samples for %V617F monitoring, available in 29 patients, showed %V617F decrease in 26 (89.6%). Median %V617F decreased from 45% before pegylated IFN-alpha-2a to 22.5%, 17.5%, 5%, and 3% after 12, 18, 24, and 36 months, respectively. Molecular CR (JAK2V617F undetectable) was achieved in 7 patients, lasting from 6(+) to 18(+) months, and persisted after pegylated IFN-alpha-2a discontinuation in 5. No vascular event was recorded. These results show that pegylated IFN-alpha-2a yields high rates of hematologic and molecular response in PV with limited toxicity, and could even eliminate the JAK2 mutated clone in selected cases. Available at www.clinicaltrials.gov as #NCT00241241.

Mantle cell lymphoma (MCL) is considered incurable. Intensive immunochemotherapy with stem cell support has not been tested in large, prospective series. In the 2nd Nordic MCL trial, we treated 160 consecutive, untreated patients younger than 66 years in a phase 2 protocol with dose-intensified induction immunochemotherapy with rituximab (R) + cyclophosphamide, vincristine, doxorubicin, prednisone (maxi-CHOP), alternating with R + high-dose cytarabine. Responders received high-dose chemotherapy with BEAM or BEAC (carmustine, etoposide, cytarabine, and melphalan/cyclophosphamide) with R-in vivo purged autologous stem cell support. Overall and complete response was achieved in 96% and 54%, respectively. The 6-year overall, event-free, and progression-free survival were 70%, 56%, and 66%, respectively, with no relapses occurring after 5 years. Multivariate analysis showed Ki-67 to be the sole independent predictor of event-free survival. The nonrelapse mortality was 5%. The majority of stem cell products and patients assessed with polymerase chain reaction (PCR) after transplantation were negative. Compared with our historical control, the Nordic MCL-1 trial, the event-free, overall, and progression-free survival, the duration of molecular remission, and the proportion of PCR-negative stem cell products were significantly increased (P < .001). Intensive immunochemotherapy with in vivo purged stem cell support can lead to long-term progression-free survival of MCL and perhaps cure. Registered at www.isrctn.org as #ISRCTN 87866680.

Chronic graft-versus-host disease (cGVHD) is a major limitation of successful hematopoietic cell transplantation. The safety and efficacy of extracorporeal photopheresis (ECP) for 12 to 24 weeks together with standard therapy was compared with standard therapy alone in patients with cutaneous manifestations of cGVHD that could not be adequately controlled by corticosteroid treatment. The primary efficacy end point was a blinded quantitative comparison of percent change from baseline in Total Skin Score (TSS) of 10 body regions at week 12. Ninety-five patients were randomized to either ECP and standard therapy (n = 48) or standard therapy alone (n = 47). The median percentage improvement in TSS at week 12 was 14.5% for the ECP arm and 8.5% for the control arm (P = .48). The proportion of patients who had at least a 50% reduction in steroid dose and at least a 25% decrease from baseline in TSS was 8.3% in the ECP arm at week 12 and 0% in the control arm (P = .04). The nonblinded investigator assessment of skin complete or partial responses revealed a significant improvement in favor of ECP (P < .001). ECP was generally well tolerated. These results suggest that ECP may have a steroid-sparing effect in the treatment of cGVHD. Clinical trials registered at www.ClinicalTrials.gov as NCT00054613.

We performed a randomized dose-ranging study, double-blind for rivaroxaban doses and open-label for the comparator (low-molecular-weight heparin followed by vitamin K antagonists) to assess the optimal dose of rivaroxaban for the treatment of deep vein thrombosis. A total of 543 patients with acute deep-venous thrombosis received rivaroxaban 20, 30, or 40 mg once daily or comparator. Treatment lasted for 84 days. The primary efficacy outcome was the 3-month incidence of the composite of symptomatic venous thromboembolic complications and asymptomatic deterioration in thrombotic burden as assessed by comparison of ultrasound and perfusion lung scanning at day 84 with baseline. The main safety outcome was the composite of major bleeding and clinically relevant nonmajor bleeding. A total of 449 (83%) of the 543 patients could be included in the per-protocol population. The primary efficacy outcome occurred in 6.1%, 5.4%, and 6.6% of the rivaroxaban 20-, 30-, and 40-mg treatment groups, respectively, and in 9.9% of those receiving standard therapy. The main safety outcome occurred in 5.9%, 6.0%, and 2.2% of the rivaroxaban 20-, 30-, and 40-mg treatment groups, respectively, and in 8.8% of those receiving standard therapy. These results with simple fixed-dose oral regimens justify phase 3 evaluations (www.ClinicalTrials.gov no.NCT00395772).

We report the outcomes of 24 patients with high-risk hematologic malignancies or bone marrow failure (BMF) who received haploidentical bone marrow transplantation (BMT) after ex vivo induction of alloantigen-specific anergy in donor T cells by allostimulation in the presence of costimulatory blockade. Ninety-five percent of evaluable patients engrafted and achieved full donor chimerism. Despite receiving a median T-cell dose of 29 x10(6)/kg, only 5 of 21 evaluable patients developed grade C (n = 4) or D (n = 1) acute graft-versus-host disease (GVHD), with only one attributable death. Twelve patients died from treatment-related mortality (TRM). Patients reconstituted T-cell subsets and immunoglobulin levels rapidly with evidence of in vivo expansion of pathogen-specific T cells in the early posttransplantation period. Five patients reactivated cytomegalovirus (CMV), only one of whom required extended antiviral treatment. No deaths were attributable to CMV or other viral infections. Only 1 of 12 evaluable patients developed chronic GVHD. Eight patients survive disease-free with normal performance scores (median follow-up, 7 years). Thus, despite significant early TRM, ex vivo alloanergization can support administration of large numbers of haploidentical donor T cells, resulting in rapid immune reconstitution with very few viral infections. Surviving patients have excellent performance status and a low rate of chronic GVHD.

One hundred ten patients with multiple myeloma (MM) failing to achieve at least near-complete remission (nCR) after a first autologous stem cell transplantation (ASCT) were scheduled to receive a second ASCT (85 patients) or a reduced-intensity-conditioning allograft (allo-RIC; 25 patients), depending on the human leukocyte antigen (HLA)-identical sibling donor availability. There was a higher increase in complete remission (CR) rate (40% vs 11%, P = .001) and a trend toward a longer progression-free survival (PFS; median, 31 months vs not reached, P = .08) in favor of allo-RIC. In contrast, it was associated with a trend toward a higher transplantation-related mortality (16% vs 5%, P = .07), a 66% chance of chronic graft-versus-host disease and no statistical difference in event-free survival and overall survival. Although the PFS plateau observed with allo-RIC is very encouraging, this procedure is associated with high morbidity and mortality, and therefore it should still be considered investigational and restricted to well-designed prospective clinical trials. This trial is registered at ClinicalTrials.gov ID number NCT00560053.

This prospective study aimed to develop reproducible diagnostic criteria for sporadic Burkitt lymphoma (BL), applicable to routine practice, and to evaluate the efficacy of dose-modified (dm) CODOX-M/IVAC in patients diagnosed using these criteria. The study was open to patients with an aggressive B-cell lymphoma with an MKI67 fraction approaching 100%. Immunophenotype and fluorescent in situ hybridization (FISH) were used to separate BL from other aggressive B-cell lymphomas. BL was characterized by the presence of a cMYC rearrangement as a sole cytogenetic abnormality occurring in patients with a germinal center phenotype with absence of BCL-2 expression and abnormal TP53 expression. A total of 128 patients were eligible for the study, of whom 58 were considered to have BL and 70 to have diffuse large B-cell lymphoma (DLBCL). There were 110 clinically fit patients who received dmCODOX-M (methotrexate, dose 3 g/m(2)) with or without IVAC according to risk group. The 2-year progression-free survival was 64% (95% confidence interval [CI] 51%-77%) for BL, 55% (95% CI 42%-66%) for DLBCL, 85% (95% CI 73%-97%) for low risk, and 49% (95% CI 38%-60%) for high-risk patients. The observed differences in outcome and other clinical features validate the proposed diagnostic criteria. Compared with the previous trial LY06 with full-dose methotrexate (6.7 g/m(2)), there was a reduction in toxicity with comparable outcomes. This study was registered at www.clinicaltrials.gov as NCT00040690.

We have explored the potential role of genetics in the development of osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients under bisphosphonate therapy. A genome-wide association study was performed using 500 568 single nucleotide polymorphisms (SNPs) in 2 series of homogeneously treated MM patients, one with ONJ (22 MM cases) and another without ONJ (65 matched MM controls). Four SNPs (rs1934951, rs1934980, rs1341162, and rs17110453) mapped within the cytochrome P450-2C gene (CYP2C8) showed a different distribution between cases and controls with statistically significant differences (P = 1.07 x 10(-6), P = 4.231 x 10(-6), P = 6.22 x 10(-6), and P = 2.15 x 10(-6), respectively). SNP rs1934951 was significantly associated with a higher risk of ONJ development even after Bonferroni correction (P corrected value = .02). Genotyping results displayed an overrepresentation of the T allele in cases compared with controls (48% vs 12%). Thus, individuals homozygous for the T allele had an increased likelihood of developing ONJ (odds ratio 12.75, 95% confidence interval 3.7-43.5).

We previously reported the feasibility of clofarabine and cytarabine combinations in AML. Questions remain as to (1) the therapeutic advantage of this combination and (2) the role of lower doses of clofarabine and cytarabine in older patients. We have conducted an adaptively randomized study of lower-dose clofarabine with or without low-dose cytarabine in previously untreated patients with AML aged 60 years and older. Patients received 30 mg/m(2) clofarabine intravenously daily for 5 days with or without 20 mg/m(2) cytarabine subcutaneously daily for 14 days as induction. Consolidation consisted of 3 days of clofarabine with or without 7 days of cytarabine. Seventy patients were enrolled. The median age was 71 years (range, 60-83 years). Sixteen patients received clofarabine and 54 the combination. Overall, 56% achieved complete remission (CR). CR rate was significantly higher with the combination (63% vs 31%; P = .025). Induction mortality was 19% with the combination versus 31% with clofarabine alone (P = .276). The combination showed better event-free survival (7.1 months vs 1.7 months; P = .04), but not overall survival (11.4 months vs 5.8 months; P = .1). Clofarabine plus low-dose cytarabine has a higher response rate than clofarabine alone with comparable toxicity. This trial is registered at www.clinicaltrials.gov as no. NCT00088218.

Warfarin dose requirements have been associated with 2 main haplotypes in VKORC1, but the responsible polymorphisms remain unknown. To search for regulatory polymorphisms, we measured allelic mRNA expression of VKORC1 in human liver, heart, and B lymphocytes. The observed 2-fold allelic mRNA expression imbalance narrowed possible candidate SNPs to -1639G>A and 1173C<T. This genotype effect was observed selectively in the liver but not in heart or lymphocytes. In vitro expression of VKORC1 gene constructs, including coding and promoter regions, failed to reveal any genotype effect on transcription and mRNA processing. Chromatin immunoprecipitation with antibodies against acetyl-histone3 and K4-trimethyl-histone3 revealed preferential association of the promoter -1639 G allele with active chromatin, consistent with enhanced mRNA expression. The minor -1639 A allele generates a suppressor E-box binding site, apparently regulating gene expression by a mechanism undetectable with reporter gene assays. A clinical association study demonstrated that promoter SNP -1639G>A, and the tightly linked intron1 SNP 1173C>T, predict warfarin dose more accurately than intron 2 SNP 1542G>C in blacks. Increased warfarin dose requirement in blacks was accounted for by lower frequency of the -1639 A allele. Therefore, -1639G>A is a suitable biomarker for warfarin dosing across ethnic populations.

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) delivers inhibitory signals to activated T cells. CTLA4 is constitutively expressed on regulatory CD4(+) T cells (Tregs), but its role in these cells remains unclear. CTLA4 blockade has been shown to induce antitumor immunity. In this study, we examined the effects of anti-CTLA4 antibody on the endogenous CD4(+) T cells in cancer patients. We show that CTLA4 blockade induces an increase not only in the number of activated effector CD4(+) T cells, but also in the number of CD4(+) FoxP3(+) Tregs. Although the effects were dose-dependent, CD4(+) FoxP3(+) regulatory T cells could be expanded at lower antibody doses. In contrast, expansion of effector T cells was seen only at the highest dose level studied. Moreover, these expanded CD4(+) FoxP3(+) regulatory T cells are induced to proliferate with treatment and possess suppressor function. Our results demonstrate that treatment with anti-CTLA4 antibody does not deplete human CD4(+) FoxP3(+) Tregs in vivo, but rather may mediate its effects through the activation of effector T cells. Our results also suggest that CTLA4 may inhibit Treg proliferation similar to its role on effector T cells. This study is registered at http://www.clinicaltrials.gov/ct2/show/NCT00064129, registry number NCT00064129.

CD4(+)CD25(high)FoxP3(+) regulatory T (Treg) cells limit antigen-specific immune responses and are a cause of suppressed anticancer immunity. In preclinical and clinical studies, we assessed the immune consequences of FoxP3(+) Treg-cell depletion in patients with advanced malignancies. We demonstrated that a CD25(high) targeting immunotoxin (denileukin diftitox) depleted FoxP3(+) Treg cells, decreased Treg-cell function, and enhanced antigen-specific T-cell responses in vitro. We then attempted to enhance antitumor immune responses in patients with carcinoembryonic antigen (CEA)-expressing malignancies by Treg-cell depletion. In a pilot study (n = 15), denileukin diftitox, given as a single dose or repeated dosing, was followed by immunizations with dendritic cells modified with the fowlpox vector rF-CEA(6D)-TRICOM. By flow cytometric analysis, we report the first direct evidence that circulating CD4(+)CD25(high)FoxP3(+) Treg cells are depleted after multiple doses of denileukin diftitox. Earlier induction of, and overall greater exposure to, the T-cell response to CEA was observed in the multiple-dose group, but not the single-dose group. These results indicate the potential for combining Treg-cell depletion with anticancer vaccines to enhance tumor antigen-specific immune responses and the need to explore dose and schedule of Treg depletion strategies in optimizing vaccine efforts.

Adoptive immunotherapy with T cells expressing a tumor-specific chimeric T-cell receptor is a promising approach to cancer therapy that has not previously been explored for the treatment of lymphoma in human subjects. We report the results of a proof-of-concept clinical trial in which patients with relapsed or refractory indolent B-cell lymphoma or mantle cell lymphoma were treated with autologous T cells genetically modified by electroporation with a vector plasmid encoding a CD20-specific chimeric T-cell receptor and neomycin resistance gene. Transfected cells were immunophenotypically similar to CD8(+) effector cells and showed CD20-specific cytotoxicity in vitro. Seven patients received a total of 20 T-cell infusions, with minimal toxicities. Modified T cells persisted in vivo 1 to 3 weeks in the first 3 patients, who received T cells produced by limiting dilution methods, but persisted 5 to 9 weeks in the next 4 patients who received T cells produced in bulk cultures followed by 14 days of low-dose subcutaneous interleukin-2 (IL-2) injections. Of the 7 treated patients, 2 maintained a previous complete response, 1 achieved a partial response, and 4 had stable disease. These results show the safety, feasibility, and potential antitumor activity of adoptive T-cell therapy using this approach. This trial was registered at www.clinicaltrials.gov as #NCT00012207.