An atlas of bloodstream-accessible bone marrow proteins for site-directed therapy of acute myeloid leukemia.

The concept of arming antibodies with bioactive payloads for a site-specific therapy of cancer has gained considerable interest in recent years. However, a successful antibody-based targeting approach critically relies on the availability of a tumor-associated target that is not only preferentially expressed in the tumor tissue but is also easily accessible for antibody therapeutics coming from the bloodstream. Here, we perfused the vasculature of healthy and acute myeloid leukemia (AML)-bearing rats with a reactive ester derivative of biotin and subsequently quantified the biotinylated proteins to identify AML-associated bone marrow (BM) antigens accessible from the bloodstream. In total, >1400 proteins were identified. Overall, 181 proteins were >100-fold overexpressed in AML as compared with normal BM. Eleven of the most differentially expressed proteins were further validated by immunohistochemistry and confocal microscopic analyses, including novel antigens highly expressed in AML cells (for example, adaptor-related protein complex 3 ß2) and in the leukemia-modified extracellular matrix (ECM) (for example, collagen-VI-α-1). The presented atlas of targetable AML-associated BM proteins provides a valuable basis for the development of monoclonal antibodies that could be used as carriers for a site-specific pharmacodelivery of cytotoxic drugs, cytokines or radionuclides to the BM in AML.

Outcome of allogeneic stem cell transplantation for AML and myelodysplastic syndrome in elderly patients (⩾60 years).

Allogeneic stem cell transplantation (SCT) remains the best curative option for patients with refractory AML or with high-risk myelodysplastic syndrome (MDS). For decades, age alone had been widely used as the primary criterion to assess eligibility for allogeneic SCT; however, prospective studies to evaluate allogeneic SCT in elderly patients are still limited. A total of 187 patients (median age of 64 years, range 60-77 years) with AML (87%) or MDS (13%) transplanted between 1999 and 2014 were included in this retrospective analysis. Relapse-free survival (RFS) and overall survival (OS) at 3 years were 32% (95% confidence interval (CI): 25-39%) and 35% (95%CI: 27-42%), respectively. Overall survival was 49% (95%CI: 35-64%) in AML patients who were transplanted in first complete remission (CR1), but even patients with active disease did benefit from transplantation, showing an OS at 3 years of 30% (95%CI: 20-40%). Multivariate analysis revealed disease- and patient-specific risk indices as independent prognostic factors for OS and non-relapse mortality (NRM). In conclusion, our monocenter results indicate that patients should not be generally withheld from allogeneic SCT because of age or disease status only. Specific risk models incorporating disease status and disease-specific risk factors at the time of transplantation as well as existing comorbidities are helpful tools to assess transplantation-associated risk factors of elderly patients.

Increasing intensity of therapies assigned at diagnosis does not improve survival of adults with acute myeloid leukemia.

We randomized 3375 adults with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome to test whether increasingly intensive chemotherapies assigned at study-entry and analyzed on an intent-to-treat basis improved outcomes. In total, 1529 subjects <60 years were randomized to receive: (1) a first course of induction therapy with high-dose cytarabine and mitoxantrone (HAM) or with standard-dose cytarabine, daunorubicin and 6-thioguanine (TAD) followed by a second course of HAM; (2) granulocyte-colony stimulating factor (G-CSF) or no G-CSF before induction and consolidation courses; and (3) high-dose therapy and an autotransplant or maintenance chemotherapy. In total, 1846 subjects ⩾60 years were randomized to receive: (1) a first induction course of HAM or TAD and second induction course of HAM (if they had bone marrow blasts ⩾5% after the first course); and (2) G-CSF or no G-CSF as above. Median follow-up was 7.4 years (range, 1 day to 14.7 years). Five-year event-free survivals (EFSs) for subjects receiving a first induction course of HAM vs TAD were 17% (95% confidence interval, 15, 18%) vs 16% (95% confidence interval 14, 18%; P=0.719). Five-year EFSs for subjects randomized to receive or not receive G-CSF were 19% (95% confidence interval 16, 21%) vs 16% (95% confidence interval 14, 19%; P=0.266). Five-year relapse-free survivals (RFSs) for subjects <60 years receiving an autotransplant vs maintenance therapy were 43% (95% confidence interval 40, 47%) vs 40 (95% confidence interval 35, 44%; P=0.535). Many subjects never achieved pre-specified landmarks and consequently did not receive their assigned therapies. These data indicate the limited impact of more intensive therapies on outcomes of adults with AML. Moreover, none of the more intensive therapies we tested improved 5-year EFS, RFS or any other outcomes.

Blood group antigen A type 3 expression is a favorable prognostic factor in advanced NSCLC.

OBJECTIVES: Several blood group-related carbohydrate antigens are prognosis-relevant markers of tumor tissues. A type 3 (repetitive A) is a blood group antigen specific for A1 erythrocytes. Its potential expression in tumor tissues has so far not been examined. MATERIAL AND METHODS: We have evaluated its expression in normal lung and in lung cancer using a novel antibody (A69-A/E8). For comparison an anti-A antibody specific to A types 1 and 2 was used, because its expression on lung cancer tissue has been previously reported to be of prognostic relevance. Resected tissue samples of 398 NSCLC patients were analyzed in immunohistochemistry using tissue microarrays. RESULTS AND CONCLUSIONS: Expression of A type 3 was not observed in non-malignant lung tissues. A type 3 was expressed on tumor cells of around half of NSCLC patients of blood group A1 (p<0.001). Whereas no prognostic effect for A type 1/2 antigen was observed (p=0.562), the expression of A type 3 by tumor cells indicated a highly significant favorable prognosis among advanced NSCLC patients (p=0.011) and in NSCLC patients with lymphatic spread (p=0.014). Univariate prognostic results were confirmed in a Cox proportional hazards model. In this study we present for the first time prognostic data for A type 3 antigen expression in lung cancer patients. Prospective studies should be performed to confirm the prognostic value of A type 3 expression for an improved risk stratification in NSCLC patients.

MN1-Fli1 oncofusion transforms murine hematopoietic progenitor cells into acute megakaryoblastic leukemia cells.

Long-term outcome of acute megakaryoblastic leukemia (AMKL) patients without Down's syndrome remains poor. Founding mutations and chimeric oncogenes characterize various AMKL subtypes. However, for around one third of all cases the underlying mechanisms of AMKL leukemogenesis are still largely unknown. Recently, an in-frame fusion of meningeoma 1-friend leukemia virus integration 1 (MN1-Fli1) gene was detected in a child with AMKL. We intended to investigate the potential role of this oncofusion in leukemogenesis of acute myeloid leukemia. Strikingly, expression of MN1-Fli1 in murine hematopoietic progenitor cells was sufficient to induce leukemic transformation generating immature myeloid cells with cytomorphology and expression of surface markers typical for AMKL. Systematic structure function analyses revealed FLS and 3'ETS domains of Fli1 as decisive domains for the AMKL phenotype. Our data highlight an important role of MN1-Fli1 in AMKL leukemogenesis and provide a basis for research assessing the value of this oncofusion as a future diagnostic marker and/or therapeutic target in AMKL patients.

Human monoclonal antibodies targeting carbonic anhydrase IX for the molecular imaging of hypoxic regions in solid tumours.

BACKGROUND: Hypoxia, which is commonly observed in areas of primary tumours and of metastases, influences response to treatment. However, its characterisation has so far mainly been restricted to the ex vivo analysis of tumour sections using monoclonal antibodies specific to carbonic anhydrase IX (CA IX) or by pimonidazole staining, after the intravenous administration of this 2-nitroimidazole compound in experimental animal models. METHODS: In this study, we describe the generation of high-affinity human monoclonal antibodies (A3 and CC7) specific to human CA IX, using phage technology. RESULTS: These antibodies were able to stain CA IX ex vivo and to target the cognate antigen in vivo. In one of the two animal models of colorectal cancer studied (LS174T), CA IX imaging closely matched pimonidazole staining, with a preferential staining of tumour areas characterised by little vascularity and low perfusion. In contrast, in a second animal model (SW1222), distinct staining patterns were observed for pimonidazole and CA IX targeting. We observed a complementary pattern of tumour regions targeted in vivo by the clinical-stage vascular-targeting antibody L19 and the anti-CA IX antibody A3, indicating that a homogenous pattern of in vivo tumour targeting could be achieved by a combination of the two antibodies. CONCLUSION: The new human anti-CA IX antibodies are expected to be non-immunogenic in patients with cancer and may serve as broadly applicable reagents for the non-invasive imaging of hypoxia and for pharmacodelivery applications.

Use of palifermin for the prevention of high-dose methotrexate-induced oral mucositis.

BACKGROUND: Oral mucositis is a frequent problem after high-dose methotrexate (HD-MTX), impairing patient's quality of life, leading to higher rates of infections and delaying subsequent chemotherapy. This report describes the effect of palifermin in patients treated within the GMALL-B-ALL 2002 protocol containing HD-MTX who developed a severe mucositis in cycle A1/B1. PATIENTS AND METHODS: Ten patients, all with World Health Organization grades III-IV oral mucositis in cycles A1/B1, obtained palifermin with subsequent similar or identical cycles to reduce mucositis. Thus, patients serve as their own control for efficacy of palifermin. RESULTS: All 10 patients developed grades III-IV mucositis in cycles A1/B1 without palifermin, whereas only two of 10 developed grades III-IV mucositis in corresponding cycles A2/B2 with palifermin. Only four of 10 patients showed infections in the cycles with palifermin compared with 10 of 10 patients without palifermin. The duration of mucositits in patients who acquired a higher grade mucositis despite treatment with palifermin could be reduced from 12.9 days (median) without to 11 days with palifermin. The amount of i.v. opioid analgetics could be significantly reduced. CONCLUSION: Palifermin might reduce the incidence, severeness and duration of oral mucositis in HD-MTX-based chemotherapy and may influence clinical sequelae such as infection and quality of life.

Amsacrine containing induction therapy in elderly AML patients: comparison to standard induction regimens in a matched-pair analysis.

Many elderly patients with newly diagnosed acute myeloid leukemia (AML) present with cardiac comorbidity precluding the use of anthracycline containing chemotherapy regimens. Amsacrine, a topoisomerase II inhibitor, has been proposed as possible alternative to anthracyclines. Here, we report about the combination of amsacrine (210 mg/m(2)), in replacement for daunorubicin (DNR), with standard dose cytarabine and thioguanine (TAA) to elderly patients (>or=60 years of age) with impaired cardiac function. The outcome of 16 patients with a median age of 66 years treated between 1997 and 2003 was compared with standard treatment regimens of the AMLCG study group in a matched-pair analysis. There were no statistically significant differences in response rate, relapse free survival or overall survival between TAA treated patients or standard therapy. In conclusion, replacing anthracyclines with amsacrine for induction therapy of AML patients with significant cardiac comorbidities represents a treatment option without compromising the potential curability of the disease.

Chemotherapy in metastatic malignant triton tumor: report on two cases.

Malignant triton tumor (MTT) is a rare, highly malignant nerve sheath tumor with rhabdomyoblastic differentiation. Initial debulking surgery followed by adjuvant therapy is the current treatment of choice, but has very limited efficacy when optimal cytoreduction is not achieved by surgical procedure. Neoadjuvant therapy for MTT, to potentially facilitate subsequent surgery, eradicate micrometastatic lesions and, therefore, improve the therapeutical outcome, has never before been presented in literature. Here, we report on the multimodal management of two cases of advanced and metastatic MTT. Treatment modalities involved neoadjuvant and adjuvant chemotherapy, surgical resection, and radiation. In both cases, integrated Positron Emission Tomography/Computed Tomography (PET/CT) emerged as an important diagnostic tool for the reliable assessment of MTT response and metabolic remission.

Circulating angiopoietin-2 is a strong prognostic factor in acute myeloid leukemia.

Angiogenesis plays an important role in solid tumors and hematologic malignancies. The angiopoietins act as essential regulators in this process. We investigated the impact of circulating angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2) and soluble Tie2 (sTie2) on overall survival in patients with acute myeloid leukemia (AML). Ang-1, Ang-2 and sTie2 were measured in plasma samples from 68 AML patients and 11 controls using enzyme-linked immunosorbent assay. Circulating levels of Ang-2 and sTie2 (median (range): 1098.0 (361.4-4147.6) pg/ml and 3.40 (1.21-10.00) ng/ml, respectively) were significantly elevated in AML patients as compared to controls (307.9 (199.7-1225.0) pg/ml and 2.88 (1.71-3.29) ng/ml; P<0.001 and P=0.014). In a univariate Cox proportional hazards model, higher levels of Ang-2 and sTie2 were predictive of poor survival. In multivariate analyses, Ang-2 and cytogenetics proved to be independent prognostic factors, with a relative risk of 4.07 (95% confidence interval (CI) 1.88-8.81) and 2.70 (95% CI 1.25-5.81), respectively. The 3-year survival rate for AML patients with Ang-2 levels>/=1495.6 pg/ml was only 14.7% compared to 64.7% for those with Ang-2 levels<1495.6 pg/ml. These data provide evidence that circulating Ang-2 represents an independent prognostic factor in AML and may be used as a prognostic tool in the risk-adapted management of AML.

Correlation of neuropilin-1 overexpression to survival in acute myeloid leukemia.

Neuropilin-1 (NRP-1), a vascular endothelial growth factors and semaphorin receptor functioning as mediator of angiogenesis and neuronal guidance, is expressed by various solid tumors. The importance of NRP-1 in hematological malignancies such as acute myeloid leukemia (AML) remains to be elucidated. Therefore, we determined NRP-1 expression by immunohistochemical analysis of bone marrow biopsies of patients with newly diagnosed, untreated AML. The expression of NRP-1 was significantly increased in AML patients (n = 76; median 12.9 arbitrary units (a.u.)) as compared with controls (n = 38; median 2.75 a.u.). Survival was significantly poorer in patients with high (> median) versus low (< or = median) NRP-1 expression levels with 5-year overall survival rates of 16.9 versus 49.6% (P = 0.050). In conclusion, our data provide evidence of increased NRP-1 expression in AML with significant correlation to survival. Thus, NRP-1 might constitute a promising target for antileukemic and antiangiogenic treatment strategies in AML.