Impact of Center Experience with Donor Type on Outcomes: A Secondary Analysis, Blood and Marrow Transplant Clinical Trials Network 1101Open for Accrual June 2012Open for Accrual June 2012.

We previously reported the results of Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 1101, a randomized comparison of hematopoietic cell transplantation (HCT) performed with double umbilical cord blood units (dUCB) or with haploidentical bone marrow (haplo-BMT) with post-transplantation cyclophosphamide (PTCy) in the nonmyeloablative setting. Those results showed similar progression-free survival in the 2 treatment groups but lower nonrelapse mortality and better overall survival in the haplo-BM arm. In this secondary analysis, we sought to investigate whether transplantation center's previous experience with haplo-BM and/or dUCB HCT had an impact on outcomes. All patients randomized in BMT CTN 1101 were included. Center experience was assigned based on the number of transplantations with each platform performed in the year before initiation of the study according to the Center for International Blood and Marrow Transplant Research. Centers were then classified as a dUCB center (>10 dUCB HCTs; n = 117 patients, 10 centers), a haplo-BM center (>10 haplo-BM HCTs and ≤10 dUCB HCTs; n = 110 patients, 2 centers), or other center (≤10 haplo and ≤10 dUCB HCTs; n = 140 patients, 21 centers). After adjusting for age, Karnofsky Performance Status, and Disease Risk Index, we found that haplo-BM centers had lower overall mortality with this donor type compared with dUCB centers (hazard ratio [HR], 2.56; 95% confidence interval [CI], 1.44 to 4.56). In contrast, there were no differences in overall mortality between haplo-BM and dUCB in centers that were experienced with dUCB HCT (HR, 1.02; 95% CI, .59 to 1.79) or had limited to no experience with either dUCB or haplo-BM HCT (HR, 1.36; 95% CI, .83 to 2.21). The higher risk of treatment failure and overall mortality in dUCB HCT in haplo BM-experienced centers was driven by a significantly higher risk of relapse (HR, 1.78; 95% CI, 1.07 to 2.97). With the exception of worse outcomes among dUCB HCT recipients in haplo-BM centers, transplantation center experience in the year before initiation of BMT CTN 1101 had a limited impact on the outcomes of this randomized clinical trial.

Umbilical Cord Blood or HLA-Haploidentical Transplantation: Real-World Outcomes versus Randomized Trial Outcomes.

Randomized clinical trials offer the highest-quality data for modifying clinical practice. Results of a phase III randomized trial of nonmyeloablative transplantation for adults with high-risk hematologic malignancies with 2 umbilical cord blood (UCB) units (n = 183) or HLA-haploidentical relative bone marrow (Haplo-BM; n = 154) revealed a 2-year progression-free survival (PFS) of 41% after Haplo-BM transplantation and 35% after 2-unit UCB transplantation (P = .41), with overall survival (OS) of 57% and 46%, respectively (P = .04). We sought to examine the generalizability of BMT CTN 1101 to a contemporaneous cohort beyond the trial's prespecified 2-year outcomes. All transplantations were performed between June 2012 and June 2018 in the United States. We hypothesized that the results of a rigorous phase III randomized trial would be generalizable. Changes in graft selection for HLA-haploidentical relative transplantation during the trial period allowed comparison of outcomes after transplantation with Haplo-BM with those after haploidentical peripheral blood (Haplo-PB). The trial's broad eligibility criteria were applied to the data source of the Center for International Blood and Marrow Transplant Research to select nontrial subjects. Extended follow-up of trial subjects was obtained from this data source. Three separate analyses were performed: (1) trial subjects beyond the trial's 2-year endpoint; (2) comparison of trial subjects with a contemporaneous cohort of nontrial subjects (195 2-unit UCB, 358 Haplo-BM, and 403 Haplo-PB); and (3) comparison of nontrial subjects by donor and graft type. Multivariate analyses were performed using Cox proportional hazards models for comparison of outcomes by treatment groups. With longer follow-up of the trial cohorts, 5-year PFS (37% versus 29%; P = .08) and OS (42% versus 36%; P = .06) were not significantly different between the treatment groups. We then compared the trial results with outcomes of comparable real-world transplantations. Five-year OS did not differ between trial and nontrial 2-unit UCB transplantations (36% versus 41%; P = .48) or between trial and nontrial Haplo-BM transplantations (42% versus 47%; P = .80), confirming generalizability. The randomized trial did not accrue as planned and therefore lacked the statistical power to detect a 15% difference in PFS. With substantially larger numbers of nontrial Haplo-BM transplantations, 5-year survival was higher after nontrial Haplo-BM compared with trial 2-unit UCB (47% versus 36%; P = .012). Nontrial patients who underwent Haplo-PB transplantation had higher 5-year survival (54%) compared with trial Haplo-BM (hazard ratio [HR], 0.76; P = .044) and nontrial Haplo-BM (HR, 0.78; P = .026). Similarly, survival was better after Haplo-PB compared with trial UCB (HR, 0.57; P < .0001) and nontrial UCB (HR, 0.63; P = .0002). When considering alternative donor low-intensity conditioning regimen transplantation, a haploidentical relative is preferred, and PB is the preferred graft source.

Type 1 interferon to prevent leukemia relapse after allogeneic transplantation.

A potent graft-versus-leukemia (GVL) response is crucial in preventing relapse, the major impediment to successful allogeneic hematopoietic cell transplantation (HCT). In preclinical studies, type 1 interferon (IFN-α) enhanced cross-presentation of leukemia-specific antigens by CD8α dendritic cells (DCs) and amplified GVL. This observation was translated into a proof-of-concept phase 1/2 clinical trial with long-acting IFN-α (pegylated IFN-α [pegIFNα]) in patients undergoing HCT for high-risk acute myeloid leukemia (AML). Patients with treatment-resistant AML not in remission or those with poor-risk leukemia were administered 4 dosages of pegIFNα every 14 days beginning at day -1 before HCT. Dose selection was established by adaptive design that continuously assessed the probability of dose-limiting toxicities throughout the trial. Efficacy was evaluated by determining the 6-month incidence of relapse at the maximum tolerated dose (MTD). Thirty-six patients (median age, 60 years) received pegIFNα treatment. Grade 3 or greater severe adverse events occurred in 25% of patients, establishing 180 µg as the MTD. In phase 2, the incidence of relapse was 39% at 6 months, which was sustained through 1-year post-HCT. The incidence of transplant-related mortality was 13%, and severe grade III-IV acute graft-versus-host disease (GVHD) occurred in 11%. Paired blood samples from donors and recipients after HCT revealed elevated levels of type 1 IFN with cellular response, the persistence of cross-presenting DCs, and circulating leukemia antigen-specific T cells. These data suggest that prophylactic administration of pegIFNα is feasible in the peri-HCT period. In high-risk AML, increased toxicity was not observed with preliminary evidence for reduction in leukemia relapse after HCT. This trial was registered at www.clinicaltrials.gov as #NCT02328755.

Double unrelated umbilical cord blood vs HLA-haploidentical bone marrow transplantation: the BMT CTN 1101 trial.

Results of 2 parallel phase 2 trials of transplantation of unrelated umbilical cord blood (UCB) or bone marrow (BM) from HLA-haploidentical relatives provided equipoise for direct comparison of these donor sources. Between June 2012 and June 2018, 368 patients aged 18 to 70 years with chemotherapy-sensitive lymphoma or acute leukemia in remission were randomly assigned to undergo UCB (n = 186) or haploidentical (n = 182) transplant. Reduced-intensity conditioning comprised total-body irradiation with cyclophosphamide and fludarabine for both donor types. Graft-versus-host disease prophylaxis for UCB transplantation was cyclosporine and mycophenolate mofetil (MMF) and for haploidentical transplantation, posttransplant cyclophosphamide, tacrolimus, and MMF. The primary end point was 2-year progression-free survival (PFS). Treatment groups had similar age, sex, self-reported ethnic origin, performance status, disease, and disease status at randomization. Two-year PFS was 35% (95% confidence interval [CI], 28% to 42%) compared with 41% (95% CI, 34% to 48%) after UCB and haploidentical transplants, respectively (P = .41). Prespecified analysis of secondary end points recorded higher 2-year nonrelapse mortality after UCB, 18% (95% CI, 13% to 24%), compared with haploidentical transplantation, 11% (95% CI, 6% to 16%), P = .04. This led to lower 2-year overall survival (OS) after UCB compared with haploidentical transplantation, 46% (95% CI, 38-53) and 57% (95% CI 49% to 64%), respectively (P = .04). The trial did not demonstrate a statistically significant difference in the primary end point, 2-year PFS, between the donor sources. Although both donor sources extend access to reduced-intensity transplantation, analyses of secondary end points, including OS, favor haploidentical BM donors. This trial was registered at www.clinicaltrials.gov as #NCT01597778.

Tisagenlecleucel in Adult Relapsed or Refractory Diffuse Large B-Cell Lymphoma.

BACKGROUND: Patients with diffuse large B-cell lymphoma that is refractory to primary and second-line therapies or that has relapsed after stem-cell transplantation have a poor prognosis. The chimeric antigen receptor (CAR) T-cell therapy tisagenlecleucel targets and eliminates CD19-expressing B cells and showed efficacy against B-cell lymphomas in a single-center, phase 2a study. METHODS: We conducted an international, phase 2, pivotal study of centrally manufactured tisagenlecleucel involving adult patients with relapsed or refractory diffuse large B-cell lymphoma who were ineligible for or had disease progression after autologous hematopoietic stem-cell transplantation. The primary end point was the best overall response rate (i.e., the percentage of patients who had a complete or partial response), as judged by an independent review committee. RESULTS: A total of 93 patients received an infusion and were included in the evaluation of efficacy. The median time from infusion to data cutoff was 14 months (range, 0.1 to 26). The best overall response rate was 52% (95% confidence interval, 41 to 62); 40% of the patients had complete responses, and 12% had partial responses. Response rates were consistent across prognostic subgroups. At 12 months after the initial response, the rate of relapse-free survival was estimated to be 65% (79% among patients with a complete response). The most common grade 3 or 4 adverse events of special interest included cytokine release syndrome (22%), neurologic events (12%), cytopenias lasting more than 28 days (32%), infections (20%), and febrile neutropenia (14%). Three patients died from disease progression within 30 days after infusion. No deaths were attributed to tisagenlecleucel, cytokine release syndrome, or cerebral edema. No differences between response groups in tumor expression of CD19 or immune checkpoint-related proteins were found. CONCLUSIONS: In this international study of CAR T-cell therapy in relapsed or refractory diffuse large B-cell lymphoma in adults, high rates of durable responses were produced with the use of tisagenlecleucel. (Funded by Novartis; JULIET ClinicalTrials.gov number, NCT02445248 .).

α1-Antitrypsin infusion for treatment of steroid-resistant acute graft-versus-host disease.

Corticosteroid resistance after acute graft-versus-host disease (SR-aGVHD) results in high morbidity and mortality after allogeneic hematopoietic cell transplantation. Current immunosuppressive therapies for SR-aGVHD provide marginal effectiveness because of poor response or excessive toxicity, primarily from infection. α1-Antitrypsin (AAT), a naturally abundant serine protease inhibitor, is capable of suppressing experimental GVHD by downmodulating inflammation and increasing ratios of regulatory (Treg) to effector T cells (Teffs). In this prospective multicenter clinical study, we sought to determine the safety and response rate of AAT administration in SR-aGVHD. Forty patients with a median age of 59 years received intravenous AAT twice weekly for 4 weeks as first-line treatment of SR-aGVHD. The primary end point was overall response rate (ORR), the proportion of patients with SR-aGVHD in complete (CR) or partial response by day 28 without addition of further immunosuppression. Treatment was well tolerated without drug-related adverse events. A significant increase in serum levels of AAT was observed after treatment. The ORR and CR rates by day 28 were 65% and 35%, respectively, and included responses in all aGVHD target organs. At day 60, responses were sustained in 73% of patients without intervening immunosuppression. Infectious mortality was 10% at 6 months and 2.5% within 30 days of last AAT infusion. Consistent with preclinical data, correlative samples showed an increase in ratio of activated Tregs to Teffs after AAT treatment. These data suggest that AAT is safe and may be potentially efficacious in treating SR-aGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01700036.

Reducing Treatment-Related Mortality Did Not Improve Outcomes of Allogeneic Myeloablative Hematopoietic Cell Transplantation for High-Risk Multiple Myeloma: A University of Michigan Prospective Series.

Despite the ongoing advent of more effective immunomodulators and proteasome inhibitors, multiple myeloma (MM) remains incurable and no effective therapy is available for advanced aggressive disease. Although allogeneic (Allo) hematopoietic cell transplantation (HCT) has a curative potential, the outcomes remain poor because of high treatment-related mortality (TRM), mostly due to regimen-related toxicities and graft-versus-host disease (GVHD) in case of myeloablative conditionings, high relapse rate in case of reduced-intensity or nonmyeloablative regimens, and possibly other unknown MM-specific issues. In an attempt to improve TRM, without compromising conditioning intensity, we prospectively explored the feasibility and efficacy of a myeloablative but reduced-toxicity conditioning regimen, consisting of fludarabine and busulfan (FluBu4; fludarabine 40 mg/m(2)/day and busulfan 3.2 mg/kg/day i.v. × 4 days) in 22 patients with high-risk or advanced refractory MM. The majority (14 of 22, 64%) had prior autologous HCT. The median HCT-specific comorbidity index score was 3 (range, 0 to 6), with 46% having a Karnofsky performance score < 80%. Ten patients had unrelated donors, 3 of whom were 7/8 HLA-loci matched. GVHD prophylaxis was tacrolimus and methotrexate in 20 (91%). Most patients had active MM at transplantation, with a partial response in 12 of 22 (46%) and stable disease in 1 of 22 (4.5%). All 22 patients tolerated the FluBu4 conditioning well, without early toxic deaths or graft failure. Common regimen-related toxicities included mild to moderate mucositis (18 of 22, 82%) and mild transient liver function abnormality (9 of 22, 41%). There were no grade 4 toxicities but grade 3 mucositis occurred in 7 of 22 patients (32%). The cumulative incidence of severe, grades III and IV acute GVHD at day 180 was 23% (95% confidence interval [CI], 10% to 47%) and that of chronic GVHD was 68% (95% CI, 46% to 88%). The cumulative incidences of TRM at 100 days, 1 year, and 3 years were 9% (95% CI, 2% to 33%), 19% (95% CI, 7% to 44%), and 29% (95% CI, 13% to 55%), respectively. Two TRMs were due to idiopathic pneumonia syndrome and 1 was due to cirrhosis. They all had decreased pre-HCT corresponding organ function, with HCT-specific comorbidity index scores of > 3. With a median follow-up of 58.7 (range, 39 to 82) months, the cumulative incidences of relapse at 1 and 3 years were 37% (95% CI, 20% to 61%) and 50% (95% CI, 29% to 75%); those for 1-year and 3-year overall survival (OS) were 58% (95% CI, 40% to 83%) and 29% (95% CI, 15% to 57%), respectively, and those for the 1-year and 3-year progression-free survivals (PFS) were 40% (95% CI, 23% to 67%) and 15% (95% CI, 5% to 42%), respectively. In summary, the use of the myeloablative FluBu4 conditioning Allo-HCT for high-risk MM resulted in decreased TRM, compared with that of Allo-HCT using conventional myeloablative regimens; however, the relapse rate was high, including in those developing moderate-to-severe chronic GVHD. This suggested a less robust graft-versus-myeloma effect against high-risk MM, thus resulting in poor PFS and OS. Nonetheless, the FluBu4 regimen may be used as a lower-TRM platform to combine with other strategies, eg, addition of an MM-targeted agent and/or maintenance therapy with these agents, to decrease relapse or progression in patients with high-risk MM.

Allogeneic transplantation with myeloablative FluBu4 conditioning improves survival compared to reduced intensity FluBu2 conditioning for acute myeloid leukemia in remission.

The optimal intensity of conditioning for allogeneic hematopoietic stem cell transplantation (HCT) in acute myeloid leukemia (AML) remains undefined. Traditionally, myeloablative conditioning regimens improve disease control, but at the risk of greater nonrelapse mortality. Because fludarabine with myeloablative doses of intravenous busulfan using pharmacokinetic monitoring has excellent tolerability, we reasoned that this regimen would limit relapse without substantially elevating toxicity when compared to reduced intensity conditioning. We retrospectively analyzed 148 consecutive AML patients in remission receiving T cell replete HCT conditioned with fludarabine and intravenous busulfan at doses defined as reduced (6.4 mg/kg; FluBu2, n = 63) or myeloablative (12.8 mg/kg; FluBu4, n = 85). Early and late nonrelapse mortality (NRM) was similar among FluBu4 and FluBu2 recipients, respectively (day + 100: 4 vs 0 %; 5 years: 19 vs 22 %; p = 0.54). NRM did not differ between FluBu4 and FluBu2 in patients >50 years of age (24 vs 22 %, p = 0.75). Relapse was lower in recipients of FluBu4 (5 years: 30 vs 49 %; p = 0.04), especially in patients with poor risk cytogenetics (22 vs 59 %; p = 0.02) and those >50 years of age (28 vs 51 %; p = 0.02). Overall survival favored FluBu4 recipients at 5 years (53 vs 34 %, p = 0.02), a finding confirmed in multivariate analysis (HR: 0.57; 95 % CI: 0.34-0.95; p = 0.03). These data suggest that myeloablative FluBu4 may provide equivalent NRM, reduced relapse, and improved survival compared to FluBu2, emphasizing the importance of busulfan dose in conditioning for AML.

Engraftment syndrome after allogeneic hematopoietic cell transplantation predicts poor outcomes.

Engraftment syndrome (ES), characterized by fever, rash, pulmonary edema, weight gain, liver and renal dysfunction, and/or encephalopathy, occurs at the time of neutrophil recovery after hematopoietic cell transplantation (HCT). In this study, we evaluated the incidence, clinical features, risk factors, and outcomes of ES in children and adults undergoing first-time allogeneic HCT. Among 927 patients, 119 (13%) developed ES at a median of 10 days (interquartile range 9 to 12) after HCT. ES patients experienced significantly higher cumulative incidence of grade 2 to 4 acute GVHD at day 100 (75% versus 34%, P < .001) and higher nonrelapse mortality at 2 years (38% versus 19%, P < .001) compared with non-ES patients, resulting in lower overall survival at 2 years (38% versus 54%, P < .001). There was no significant difference in relapse at 2 years (26% versus 31%, P = .772). Suppression of tumorigenicity 2, interleukin 2 receptor alpha, and tumor necrosis factor receptor 1 plasma biomarker levels were significantly elevated in ES patients. Our results illustrate the clinical significance and prognostic impact of ES on allogeneic HCT outcomes. Despite early recognition of the syndrome and prompt institution of corticosteroid therapy, outcomes in ES patients were uniformly poor. This study suggests the need for a prospective approach of collecting clinical features combined with correlative laboratory analyses to better characterize ES.

Etanercept plus topical corticosteroids as initial therapy for grade one acute graft-versus-host disease after allogeneic hematopoietic cell transplantation.

Clinical diagnosis of grade 1 acute graft-versus-host disease (GVHD) marks the beginning of a potentially progressive and fatal course of GVHD after hematopoietic stem cell transplantation (HSCT). However, interventional studies to treat early GVHD are lacking. We conducted a single-arm prospective phase II trial to test the hypothesis that treatment of newly diagnosed grade 1 acute GVHD with etanercept and topical corticosteroids would reduce progression to grade 2 to 4 within 28 days. Study patients (n = 34) had a median age of 51 years (range, 10 to 67 years) and had undergone unrelated (n = 22) or related (n = 12) donor HSCT. Study patients were treated with etanercept (.4 mg/kg, maximum 25 mg/dose) twice weekly for 4 to 8 weeks. Ten of 34 patients (29%) progressed to grade 2 to 4 acute GVHD within 28 days. The cumulative incidence of grade 2 to 4 and grade 3 to 4 acute GVHD at 1 year was 41% and 3%, respectively. Nonrelapse mortality was 19% and overall survival was 63% at 2 years. Among a contemporaneous control cohort of patients who were diagnosed with grade 1 acute GVHD and treated with topical corticosteroids but not etanercept during the study period, 12 of 28 patients (43%) progressed to grade 2 to 4 GVHD within 28 days, with a 1-year incidence of grade 2 to 4 GVHD and grade 3 to 4 GVHD of 61% (41% versus 61%, P = .08) and 18% (3% versus 18%, P = .05), respectively. Patients treated with etanercept also experienced less increase in GVHD plasma biomarkers suppression of tumorigenicity 2 (P = .06) and regenerating islet-derived 3-alpha (P = .01) 28 days after grade 1 acute GVHD diagnosis compared with contemporaneous control patients. This study was terminated early because of poor accrual. Future prospective studies are needed to identify patients with grade 1 acute GVHD at risk of swift progression to more severe GVHD and to establish consensus for the treatment of grade 1 acute GVHD. This trial is registered with ClinicalTrials.gov, number NCT00726375.

Vorinostat plus tacrolimus and mycophenolate to prevent graft-versus-host disease after related-donor reduced-intensity conditioning allogeneic haemopoietic stem-cell transplantation: a phase 1/2 trial.

BACKGROUND: Acute graft-versus-host disease (GVHD) remains a barrier to more widespread application of allogeneic haemopoietic stem-cell transplantation. Vorinostat is an inhibitor of histone deacetylases and was shown to attenuate GVHD in preclinical models. We aimed to study the safety and activity of vorinostat, in combination with standard immunoprophylaxis, for prevention of GVHD in patients undergoing related-donor reduced-intensity conditioning haemopoietic stem-cell transplantation. METHODS: Between March 31, 2009, and Feb 8, 2013, we did a prospective, single-arm, phase 1/2 study at two centres in the USA. We recruited adults (aged ≥18 years) with high-risk haematological malignant diseases who were candidates for reduced-intensity conditioning haemopoietic stem-cell transplantation and had an available 8/8 or 7/8 HLA-matched related donor. All patients received a conditioning regimen of fludarabine (40 mg/m(2) daily for 4 days) and busulfan (3.2 mg/kg daily for 2 days) and GVHD immunoprophylaxis of mycophenolate mofetil (1 g three times a day, days 0-28) and tacrolimus (0.03 mg/kg a day, titrated to a goal level of 8-12 ng/mL, starting day -3 until day 180). Vorinostat (either 100 mg or 200 mg, twice a day) was initiated 10 days before haemopoietic stem-cell transplantation until day 100. The primary endpoint was the cumulative incidence of grade 2-4 acute GVHD by day 100. This trial is registered with ClinicalTrials.gov, number NCT00810602. FINDINGS: 50 patients were assessable for both toxic effects and response; eight additional patients were included in the analysis of toxic effects. All patients engrafted neutrophils and platelets at expected times after haemopoietic stem-cell transplantation. The cumulative incidence of grade 2-4 acute GVHD by day 100 was 22% (95% CI 13-36). The most common non-haematological adverse events included electrolyte disturbances (n=15), hyperglycaemia (11), infections (six), mucositis (four), and increased activity of liver enzymes (three). Non-symptomatic thrombocytopenia after engraftment was the most common haematological grade 3-4 adverse event (nine) but was transient and all cases resolved swiftly. INTERPRETATION: Administration of vorinostat in combination with standard GVHD prophylaxis after related-donor reduced-intensity conditioning haemopoietic stem-cell transplantation is safe and is associated with a lower than expected incidence of severe acute GVHD. Future studies are needed to assess the effect of vorinostat for prevention of GVHD in broader settings of haemopoietic stem-cell transplantation. FUNDING: Merck, Leukemia and Lymphoma Society, National Institutes of Health, St Baldrick's Foundation, Michigan Institute for Clinical and Health Research.

Frequency of CD4(+)CD25(hi)FOXP3(+) regulatory T cells has diagnostic and prognostic value as a biomarker for acute graft-versus-host-disease.

The relationship between regulatory T cells (Tregs) and acute graft-versus-host disease (aGVHD) in clinical allogeneic bone marrow transplantation (BMT) recipients is not well established. We conducted a prospective analysis of peripheral blood Tregs as determined by the frequency of CD4(+)CD25(hi)FOXP3(+) lymphocytes in 215 BMT patients. Autologous BMT patients (N = 90) and allogeneic BMT patients without GVHD (N = 65) had similar Treg frequencies, whereas allogeneic patients with GVHD (N = 60) had Treg frequencies that were 40% less than those without GVHD. Treg frequencies decreased linearly with increasing grades of GVHD at onset, and correlated with eventual maximum grade of GVHD (P < .001). In addition, frequency of Tregs at onset of GVHD predicted the response to GVHD treatment (P = .003). Patients with Treg frequencies less than the median had higher nonrelapse mortality (NRM) than patients with Tregs greater than the median, but experienced equivalent relapse mortality, resulting in an inferior survival at 2 years (38% versus 63%, P = .03). Treg frequency may therefore have important prognostic value as a biomarker of aGVHD.

New targets for therapy of sarcoma.

PURPOSE OF REVIEW: Systemic treatment options for advanced sarcoma remain limited. Emerging trends exploring targeted therapy for the treatment of sarcoma are reviewed here. RECENT FINDINGS: Effective treatments for metastatic sarcoma after the failure of front line regimens, such as doxorubicin, ifosfamide, and gemcitabine with docetaxel, are clearly limited. Translational research has identified a significant proportion of sarcomas with characteristic molecular changes potentially amenable to targeted therapy. Aberrant signaling of mammalian target of rapamycin and tyrosine kinase pathways have been focal points of recent research. Early trials investigating biologic inhibitors of these pathways have yielded varied clinical results. Agents targeting stem cell factor receptor (C-KIT), platelet-derived growth factor receptor, mammalian target of rapamycin, and vascular endothelial growth factor receptor have all shown efficacy to some degree in advanced sarcoma. The insulinlike growth factor-1 receptor is a potentially important target for sarcoma treatment based on early clinical results. SUMMARY: Sarcomas are a heterogeneous group of tumors and targeted agents likely have a long-term role in their treatment. Identifying critical pathways in sarcomagenesis, susceptible subtypes and developing novel combinations remain the focus of future research.