An atypical GABARAP binding module drives the pro-autophagic potential of the AML-associated NPM1c variant

The nucleolar scaffold protein NPM1 is a multifunctional regulator of cellular homeostasis, genome integrity, and stress response. NPM1 mutations, known as NPM1c variants promoting its aberrant cytoplasmic localization, are the most frequent genetic alterations in acute myeloid leukemia (AML). A hallmark of AML cells is their dependency on elevated autophagic flux. Here, we show that NPM1 and NPM1c induce the autophagy-lysosome pathway by activating the master transcription factor TFEB, thereby coordinating the expression of lysosomal proteins and autophagy regulators. Importantly, both NPM1 and NPM1c bind to autophagy modifiers of the GABARAP subfamily through an atypical binding module preserved within its N terminus. The propensity of NPM1c to induce autophagy depends on this module, likely indicating that NPM1c exerts its pro-autophagic activity by direct engagement with GABARAPL1. Our data report a non-canonical binding mode of GABARAP family members that drives the pro-autophagic potential of NPM1c, potentially enabling therapeutic options.

Deciphering the mitophagy receptor network identifies a crucial role for OPTN (optineurin) in acute myeloid leukemia

The selective autophagic degradation of mitochondria via mitophagy is essential for preserving mitochondrial homeostasis and, thereby, disease maintenance and progression in acute myeloid leukemia (AML). Mitophagy is orchestrated by a variety of mitophagy receptors whose interplay is not well understood. Here, we established a pairwise multiplexed CRISPR screen targeting mitophagy receptors to elucidate redundancies and gain a deeper understanding of the functional interactome governing mitophagy in AML. We identified OPTN (optineurin) as sole non-redundant mitophagy receptor and characterized its unique role in AML. Knockdown and overexpression experiments demonstrated that OPTN expression is rate-limiting for AML cell proliferation. In a MN1-driven murine transplantation model, loss of OPTN prolonged overall median survival by 7 days (+21%). Mechanistically, we found broadly impaired mitochondrial respiration and function with increased mitochondrial ROS, that most likely caused the proliferation defect. Our results decipher the intertwined network of mitophagy receptors in AML for both ubiquitin-dependent and receptor-mediated mitophagy, identify OPTN as a non-redundant tool to study mitophagy in the context of leukemia and suggest OPTN inhibition as an attractive therapeutic strategy.Abbreviations: AML: acute myeloid leukemia; CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats; CTRL: control; DFP: deferiprone; GI: genetic interaction; KD: knockdown; KO: knockout; ldMBM, lineage-depleted murine bone marrow; LFC: log2 fold change; LIR: LC3-interacting region; LSC: leukemic stem cell; MAGeCK: Model-based Analysis of Genome-wide CRISPR-Cas9 Knockout; MDIVI-1: mitochondrial division inhibitor 1; MOI: multiplicity of infection; MOM: mitochondrial outer membrane; NAC: N-acetyl-L-cysteine; OA: oligomycin-antimycin A; OCR: oxygen consumption rate; OE: overexpression; OPTN: optineurin; PINK1: PTEN induced putative kinase 1; ROS: reactive oxygen species; SEM: standard error of the mean; TCGA: The Cancer Genome Atlas; TEM: transmission electron microscopy; UBD: ubiquitin-binding domain; WT: wild type.

Colorectal Cancer Organoid-Stroma Biobank Allows Subtype-Specific Assessment of Individualized Therapy Responses

In colorectal cancers, the tumor microenvironment plays a key role in prognosis and therapy efficacy. Patient-derived tumor organoids (PDTO) show enormous potential for preclinical testing; however, cultured tumor cells lose important characteristics, including the consensus molecular subtypes (CMS). To better reflect the cellular heterogeneity, we established the colorectal cancer organoid-stroma biobank of matched PDTOs and cancer-associated fibroblasts (CAF) from 30 patients. Context-specific phenotyping showed that xenotransplantation or coculture with CAFs improves the transcriptomic fidelity and instructs subtype-specific stromal gene expression. Furthermore, functional profiling in coculture exposed CMS4-specific therapeutic resistance to gefitinib and SN-38 and prognostic expression signatures. Chemogenomic library screening identified patient- and therapy-dependent mechanisms of stromal resistance including MET as a common target. Our results demonstrate that colorectal cancer phenotypes are encrypted in the cancer epithelium in a plastic fashion that strongly depends on the context. Consequently, CAFs are essential for a faithful representation of molecular subtypes and therapy responses ex vivo.

SIGNIFICANCE

Systematic characterization of the organoid-stroma biobank provides a resource for context dependency in colorectal cancer. We demonstrate a colorectal cancer subtype memory of PDTOs that is independent of specific driver mutations. Our data underscore the importance of functional profiling in cocultures for improved preclinical testing and identification of stromal resistance mechanisms. This article is featured in Selected Articles from This Issue, p. 2109.

Midostaurin in addition to intensive chemotherapy in acute myeloid leukemia with t(8;21) and KIT and/or FLT3- ITD mutations: results of the SAL MIDOKIT trial

Not available.

Bone Marrow Assessment in Liver Cirrhosis Patients with Otherwise Unexplained Peripheral Blood Cytopenia

We performed a retrospective single-center analysis to investigate the diagnostic yield of bone marrow puncture in patients with liver cirrhosis and cytopenia. Liver cirrhosis patients receiving bone marrow aspiration or biopsy for the diagnostic work-up of otherwise unexplained peripheral blood cytopenia at our institution between 2004 and 2020 were enrolled in this study. We evaluated findings from cytologic, histologic and immunologic assessment and final diagnostic outcomes. A total of 118 patients with a median age of 55 years and a median Child-Pugh score of B (8 points) were enrolled. The main etiologies of liver cirrhosis were viral hepatitis (B and C) or chronic alcohol consumption. The majority of patients (60%) exhibited concurrent anemia, leukocytopenia and thrombocytopenia. Bone marrow assessment revealed normal, unspecific or reactive alterations in 117 out of 118 patients (99%). One patient was diagnosed with myelodysplastic syndrome. Our findings suggest that peripheral blood cytopenia in patients with liver cirrhosis is rarely associated with a primary bone marrow pathology.

Early-onset venous thromboembolisms in newly diagnosed non-promyelocytic acute myeloid leukemia patients undergoing intensive induction chemotherapy

OBJECTIVES AND METHODS

Venous thromboembolic (VTE) events are emerging as frequent complications in acute myeloid leukemia (AML); however, there is insufficient data regarding epidemiology, risk factors, and impact on outcomes. The optimal approach to balance risks of thrombosis and hemorrhage remains unclear. This retrospective single-center study in AML patients undergoing induction chemotherapy between 2007 and 2018 assessed incidence, risk factors, features, and outcomes of early-onset VTE.

RESULTS

423 patients (median age 59 years) were enrolled. VTE was diagnosed in 31 patients (7.3%) within 3 months of admission. The median time to VTE was 3 days. Non-central venous catheter (CVC)-related VTE occurred in 19 patients (61%). Main risk factor for VTE was leukocytosis at admission, independent of platelet counts/INR. Four patients (13%) exhibited VTE recurrence. No deaths directly related to VTE or major bleeding events associated with platelet-adjusted anticoagulation in patients with VTE were recorded. There was no clear impact of VTE on 1-year overall survival; however, non-CVC-related VTE may be associated with adverse outcomes.

CONCLUSIONS

Early-onset VTE is a common complication in newly diagnosed AML patients admitted for induction chemotherapy. Leukocytosis is an independent VTE risk factor. The potentially adverse impact of non-CVC-related VTE merits further study.

Diagnostic yield, indications, and outcomes of cranial imaging in AML patients admitted for intensive induction or consolidation chemotherapy: a single-center experience

Cranial imaging (CI) is a widely used diagnostic procedure, especially in acute myeloid leukemia (AML) patients with suspected bleeding or infection. However, common clinical decision rules to guide CI do not apply to AML patients and the diagnostic yield and outcomes of CI for AML patients are largely unknown. We retrospectively evaluated all CI from newly diagnosed non-promyelocytic AML patients receiving intensive induction or consolidation chemotherapy between 2007 and 2019 for imaging indications, diagnostic yield, and consequences. A total of 110 of 462 patients (24%) received CI for 152 imagings in distinct clinical situations. Forty-four patients (40%) had at least one new and acute pathological finding. Main indication was focal neurologic deficit, craniocerebral trauma, and suspected cerebral hypertension. The most common new finding was intracranial hemorrhage (13% of all imagings), followed by sinusitis (9%). CI led to therapy change in 21 patients. There were no clear associations between indications, laboratory values, and a positive imaging. Positive imaging was associated with adverse overall survival. Our study suggests that the overall rate of ordered CI was appropriate and that CI should generally be performed at a low threshold. A systematized approach to CI may further increase diagnostic yield but is complicated by variable clinical presentation.

SpinTip: A Simple, Robust, and Versatile Preanalytical Method for Microscale Suspension Cell Proteomics

Sample loss and contamination are critical preanalytical pitfalls in microscale proteomic applications of nonadhering cells. Common assays and workflows are not easily adoptable to microscale sample sizes of suspension cells due to inadvertent sample loss. This impedes preanalytical experimental manipulation of limited suspension cell samples for microscale proteomics applications, such as encountered for primary human materials. Here, we describe and test a simple manual batch technique for single-step 100-fold concentration of scarce numbers of diluted suspension cells (down to 5000 cells) by volume reduction, facilitating microscale experiments with suspension cells. Pipette tips with heat-sealed orifices (SpinTips) are manufactured within 1 min and serve as versatile microcentrifugation vessels from which supernatant can be aspirated with minimal cell loss. A residual volume of approximately 3 μL can be achieved without visualization of the cell pellet. The results show that SpinTips enable the concentration, medium exchange, washing, and culture of highly limited amounts of suspension cells for functional manipulation and microscale proteomics and are readily incorporated into standard workflows. The application is illustrated by profiling ex vivo responses of primary acute myeloid leukemia (AML) cells from one AML patient to daunorubicin (DNR) to a depth of 3462 quantified proteins with excellent repeatability.

Gene expression-based prediction of pazopanib efficacy in sarcoma

BACKGROUND

The multi-receptor tyrosine kinase inhibitor pazopanib is approved for the treatment of advanced soft-tissue sarcoma and has also shown activity in other sarcoma subtypes. However, its clinical efficacy is highly variable, and no reliable predictors exist to select patients who are likely to benefit from this drug.

PATIENTS AND METHODS

We analysed the molecular profiles and clinical outcomes of patients with pazopanib-treated sarcoma enrolled in a prospective observational study by the German Cancer Consortium, DKTK MASTER, that employs whole-genome/exome sequencing and transcriptome sequencing to inform the care of young adults with advanced cancer across histology and patients with rare cancers.

RESULTS

Among 109 patients with available whole-genome/exome sequencing data, there was no correlation between clinical parameters, specific genetic alterations or mutational signatures and clinical outcome. In contrast, the analysis of a subcohort of 62 patients who underwent molecular analysis before pazopanib treatment and had transcriptome sequencing data available showed that mRNA levels of NTRK3 (hazard ratio [HR] = 0.53, p = 0.021), IGF1R (HR = 1.82, p = 0.027) and KDR (HR = 0.50, p = 0.011) were independently associated with progression-free survival (PFS). Based on the expression of these multi-receptor tyrosine kinase genes, i.e. the features NTRK3-high, IGF1R-low and KDR-high, we developed a pazopanib efficacy predictor that stratified patients into three groups with significantly different PFS (p < 0.0001). Application of the pazopanib efficacy predictor to an independent cohort of patients with pazopanib-treated sarcoma from DKTK MASTER (n = 43) confirmed its potential to separate patient groups with significantly different PFS (p = 0.02), whereas no such association was observed in patients with sarcoma from DKTK MASTER (n = 97) or The Cancer Genome Atlas sarcoma cohort (n = 256) who were not treated with pazopanib.

CONCLUSION

A score based on the combined expression of NTRK3, IGF1R and KDR allows the identification of patients with sarcoma and with good, intermediate and poor outcome following pazopanib therapy and warrants prospective investigation as a predictive tool to optimise the use of this drug in the clinic.

Kapazität der onkologischen Versorgung in deutschen onkologischen Spitzenzentren während der ersten 2 Jahre der COVID-19-Pandemie

Hintergrund

Eine zunehmende Zahl von internationalen Studien zeigt, dass die COVID-19-Pandemie schwerwiegende negative Auswirkungen auf die rechtzeitige Diagnose von Krebs und auf die Krebsbehandlung hat.

Ziel der Arbeit

Ziel der Arbeit war die quantitative und qualitative Auswertung der Kapazitäten deutscher onkologischer Spitzenzentren (Comprehensive Cancer Centers, CCCs) in verschiedenen Bereichen der komplexen onkologischen Versorgung im Zeitraum März 2020 bis Juni 2022.

Material und Methoden

Unter 18 CCCs in Deutschland erfolgte zwischen März 2020 und Juni 2022 eine prospektive regelmäßige Panelerhebung.

Ergebnisse

Die COVID-19-Pandemie hat in den ersten beiden Jahren das onkologische Versorgungssystem in Deutschland substanziell beeinträchtigt. Anhaltende Einschränkungen der Versorgung in den CCCs betrafen in erster Linie die Nachsorge (−21 %) und die Psychoonkologie (−12 %), aber auch Tumoroperationen (−9 %). Deutliche Funktions- und Kapazitätseinschränkungen fanden sich ebenso in allen weiteren Bereichen der multidisziplinären onkologischen Betreuung.

Diskussion

Die Studie dokumentiert die eingeschränkte onkologische Versorgung der Bevölkerung während der COVID-19-Pandemie. Die Auswirkungen lassen sich noch nicht vollumfänglich darstellen. Dennoch müssen (jetzt) Strategien zur Vermeidung solcher Einschränkungen entwickelt werden.

Intracranial hemorrhage in newly diagnosed non-promyelocytic acute myeloid leukemia patients admitted for intensive induction chemotherapy

OBJECTIVES AND METHODS

Intracranial hemorrhage (ICH) in acute myeloid leukemia (AML) patients is a major concern due to the increased risk of mortality. Few studies have examined ICH specifically in newly diagnosed AML patients receiving intensive induction chemotherapy (IC) and prophylactic platelet transfusions during thrombocytopenia <10/nL. This retrospective cohort study included 423 newly diagnosed AML patients without acute promyelocytic leukemia who underwent IC between 2007 and 2019. We assessed risk factors, clinical features, and outcomes of ICH.

RESULTS

17 of 423 patients (4%) suffered ICH during hospital stay, and 4 patients (24%) died directly because of ICH despite routine prophylactic platelet transfusions. Patients with ICH had a negatively impacted overall survival (median OS, 20.1 vs. 104.8 months) and were more likely not to continue with curative treatment. Main risk factors were female gender, severe thrombocytopenia, and decreased fibrinogen. Patients with subsequent ICH also had laboratory signs of liver dysfunction.

CONCLUSIONS

Intracranial hemorrhage remains a potentially deadly complication with notable incidence despite prophylactic platelet substitution, suggesting that additional prophylactic interventions may be required to further reduce the frequency of ICH in high-risk patients. Unrecognized genetic factors may simultaneously predispose to AML and platelet dysfunction with ICH.

Comprehensive Genomic and Transcriptomic Analysis for Guiding Therapeutic Decisions in Patients with Rare Cancers

The clinical relevance of comprehensive molecular analysis in rare cancers is not established. We analyzed the molecular profiles and clinical outcomes of 1,310 patients (rare cancers, 75.5%) enrolled in a prospective observational study by the German Cancer Consortium that applies whole-genome/exome and RNA sequencing to inform the care of adults with incurable cancers. Based on 472 single and six composite biomarkers, a cross-institutional molecular tumor board provided evidence-based management recommendations, including diagnostic reevaluation, genetic counseling, and experimental treatment, in 88% of cases. Recommended therapies were administered in 362 of 1,138 patients (31.8%) and resulted in significantly improved overall response and disease control rates (23.9% and 55.3%) compared to previous therapies, translating into a progression-free survival ratio >1.3 in 35.7% of patients. These data demonstrate the benefit of molecular stratification in rare cancers and represent a resource that may promote clinical trial access and drug approvals in this underserved patient population.

Targetable ERBB2 mutations identified in neurofibroma/schwannoma hybrid nerve sheath tumors

BACKGROUNDNeurofibroma/schwannoma hybrid nerve sheath tumors (N/S HNSTs) are neoplasms associated with larger nerves that occur sporadically and in the context of schwannomatosis or neurofibromatosis type 2 or 1. Clinical management of N/S HNSTs is challenging, especially for large tumors, and established systemic treatments are lacking.METHODSWe used next-generation sequencing and array-based DNA methylation profiling to determine the clinically actionable genomic and epigenomic landscapes of N/S HNSTs.RESULTSWhole-exome sequencing within a precision oncology program identified an activating mutation (p.Asp769Tyr) in the catalytic domain of the ERBB2 receptor tyrosine kinase in a patient with schwannomatosis-associated N/S HNST, and targeted treatment with the small-molecule ERBB inhibitor lapatinib led to prolonged clinical benefit and a lasting radiographic and metabolic response. Analysis of a multicenter validation cohort revealed recurrent ERBB2 mutations (p.Leu755Ser, p.Asp769Tyr, p.Val777Leu) in N/S HNSTs occurring in patients who met diagnostic criteria for sporadic schwannomatosis (3 of 7 patients), but not in N/S HNSTs arising in the context of neurofibromatosis (6 patients) or outside a tumor syndrome (1 patient), and showed that ERBB2-mutant N/S HNSTs cluster in a distinct subgroup of peripheral nerve sheath tumors based on genome-wide DNA methylation patterns.CONCLUSIONThese findings uncover a key biological feature of N/S HNSTs that may have important diagnostic and therapeutic implications.FUNDINGThis work was supported by grant H021 from DKFZ-HIPO, the University Cancer Center Frankfurt, and the Frankfurt Research Funding Clinician Scientist Program.

Use of carbapenems and glycopeptides increases risk for Clostridioides difficile infections in acute myeloid leukemia patients undergoing intensive induction chemotherapy

Patients with acute myeloid leukemia (AML) are often exposed to broad-spectrum antibiotics and thus at high risk of Clostridioides difficile infections (CDI). As bacterial infections are a common cause for treatment-related mortality in these patients, we conducted a retrospective study to analyze the incidence of CDI and to evaluate risk factors for CDI in a large uniformly treated AML cohort. A total of 415 AML patients undergoing intensive induction chemotherapy between 2007 and 2019 were included in this retrospective analysis. Patients presenting with diarrhea and positive stool testing for toxin-producing Clostridioides difficile were defined to have CDI. CDI was diagnosed in 37 (8.9%) of 415 AML patients with decreasing CDI rates between 2013 and 2019 versus 2007 to 2012. Days with fever, exposition to carbapenems, and glycopeptides were significantly associated with CDI in AML patients. Clinical endpoints such as length of hospital stay, admission to ICU, response rates, and survival were not adversely affected. We identified febrile episodes and exposition to carbapenems and glycopeptides as risk factors for CDI in AML patients undergoing induction chemotherapy, thereby highlighting the importance of interdisciplinary antibiotic stewardship programs guiding treatment strategies in AML patients with infectious complications to carefully balance risks and benefits of anti-infective agents.

Distinct immune evasion in APOBEC-enriched, HPV-negative HNSCC

Immune checkpoint inhibition leads to response in some patients with head and neck squamous cell carcinoma (HNSCC). Robust biomarkers are lacking to date. We analyzed viral status, gene expression signatures, mutational load and mutational signatures in whole exome and RNA-sequencing data of the HNSCC TCGA dataset (n = 496) and a validation set (DKTK MASTER cohort, n = 10). Public single-cell gene expression data from 17 HPV-negative HNSCC were separately reanalyzed. APOBEC3-associated TCW motif mutations but not total single nucleotide variant burden were significantly associated with inflammation. This association was restricted to HPV-negative HNSCC samples. An APOBEC-enriched, HPV-negative subgroup was identified, that showed higher T-cell inflammation and immune checkpoint expression, as well as expression of APOBEC3 genes. Mutations in immune-evasion pathways were also enriched in these tumors. Analysis of single-cell sequencing data identified expression of APOBEC3B and 3C genes in malignant cells. We identified an APOBEC-enriched subgroup of HPV-negative HNSCC with a distinct immunogenic phenotype, potentially mediating response to immunotherapy.

Reducing the red blood cell transfusion threshold from 8·0 g/dl to 7·0 g/dl in acute myeloid leukaemia patients undergoing induction chemotherapy reduces transfusion rates without adversely affecting patient outcome

BACKGROUND AND OBJECTIVES

Red blood cell (RBC) transfusions are needed by almost every acute myeloid leukaemia (AML) patient undergoing induction chemotherapy and constitute a cornerstone in supportive measures for cancer patients in general. Randomized controlled trials have shown non-inferiority or even superiority of restrictive transfusion guidelines over liberal transfusion guidelines in specific clinical situations outside of medical oncology. In this study, we analysed whether more restrictive RBC transfusion reduces blood use without affecting hard outcomes.

MATERIALS AND METHODS

A total of 352 AML patients diagnosed between 2007 and 2018 and undergoing intensive induction chemotherapy were included in this retrospective analysis. In the less restrictive transfusion group, patients received RBC transfusion for haemoglobin levels below 8 g/dl (2007-2014). In the restrictive transfusion group, patients received RBC transfusion for haemoglobin levels below 7 g/dl (2016-2018). Liberal transfusion triggers were never endorsed.

RESULTS

A total of 268 (76·1%) and 84 (23·9%) AML patients fell into the less restrictive and restrictive transfusion groups, respectively. The less restrictive transfusion group had 1 g/dl higher mean haemoglobin levels, received their first RBC transfusions earlier and needed 1·5 more units of RBC during the hospital stay of induction chemotherapy. Febrile episodes, C-reactive protein levels, admission to the intensive care unit, length of hospital stay as well as response and survival rates did not differ between the two cohorts.

CONCLUSION

From our retrospective analysis, we conclude that a more restrictive transfusion trigger does not affect important outcomes of AML patients. The opportunity to test possible effects of the more severe anaemia in the restrictive transfusion group on quality of life was missed.

The "INSIGHT" Trial: Two new strata of an explorative, open-labeled phase I study evaluating the feasibility and safety of subcutaneous IMP321 injections (LAG-3Ig fusion protein, eftilagimod alpha) combined with either standard-of-care drug therapy or PD-L1 inhibition (avelumab) in advanced-stage solid tumor entities

TPS2651

Background: The two new strata of the INSIGHT trial evaluate feasibility and safety of s.c. injections of IMP321 (eftilagimod alpha) in combination with either SOC first/second-line drug therapy (Stratum C) or in combination with an PD-L1 inhibitor (avelumab; Stratum D) in advanced stage solid tumors as well as to generate first efficacy data. This proof-of-concept data could build the basis for further clinical studies exploring the therapeutic potential of combinations of active immunotherapy using IMP321 with SOC drug therapies or immunotherapies targeting the PD-1/PD-L1 axis in various solid tumor entities. IMP321 is a MHC class II agonist that activates antigen-presenting cells (primary target cells) and then CD8 T cells (secondary target cells). Activation of the dendritic cell network and subsequent T cell recruitment at the tumor site with IMP321 may lead to enhanced anti-tumor CD8 T cell responses. Thus, especially combinations with PD-1/PD-L1 inhibitors might display interesting effects by activating immune cells and disabling immune inhibitory mechanisms at the same time. Methods: This is a prospective investigator initiated phase I trial consisting of four strata. New stratum C: Patients with solid tumors treated with SOC chemo- or targeted therapy in first or second line receive concomitant s.c. IMP321 injections. This combination is aimed to enhance the immune response against tumor cells compared to chemo-/targeted SOC therapy alone. New stratum D: Patients will receive avelumab i.v. q2w along with s.c. IMP321 injections. This combination is aimed to enhance efficacy by combining IMP321’s activating effects on immune cells with the release of immune inhibitory effects caused by interruption of the PD-1/PD-L1 axis. It is planned to enroll 20 patients in Stratum C and 12 patients in stratum D. Main efficacy endpoint is the overall response rate (RECIST 1.1). Overall recruitment has started; currently (Feb 2019) 14 patients have been enrolled. EudraCT: 2016-002309-20. Clinical trial information: NCT03252938.

Innovating the outreach of comprehensive cancer centers

In many countries, a majority of cancer patients are not treated at comprehensive cancer centers. Even for those that are, parts of the treatment or follow‐up may be carried out in local community hospitals or in private practices. How to assure quality in cancer care and create innovation? How to integrate decentralized versus centralized patient care, education, and cancer research? Outlined here is a 360° view of outreach to include all stakeholders—most importantly patients and their families, patient advocacy groups, healthcare providers, health insurers, and policymakers.

Improved Outcomes With Retinoic Acid and Arsenic Trioxide Compared With Retinoic Acid and Chemotherapy in Non–High-Risk Acute Promyelocytic Leukemia: Final Results of the Randomized Italian-German APL0406 Trial

Purpose

The initial results of the APL0406 trial showed that the combination of all- trans-retinoic acid (ATRA) and arsenic trioxide (ATO) is at least not inferior to standard ATRA and chemotherapy (CHT) in first-line therapy of low- or intermediate-risk acute promyelocytic leukemia (APL). We herein report the final analysis on the complete series of patients enrolled onto this trial.

Patients and Methods

The APL0406 study was a prospective, randomized, multicenter, open-label, phase III noninferiority trial. Eligible patients were adults between 18 and 71 years of age with newly diagnosed, low- or intermediate-risk APL (WBC at diagnosis ≤ 10 × 109/L). Overall, 276 patients were randomly assigned to receive ATRA-ATO or ATRA-CHT between October 2007 and January 2013.

Results

Of 263 patients evaluable for response to induction, 127 (100%) of 127 patients and 132 (97%) of 136 patients achieved complete remission (CR) in the ATRA-ATO and ATRA-CHT arms, respectively ( P = .12). After a median follow-up of 40.6 months, the event-free survival, cumulative incidence of relapse, and overall survival at 50 months for patients in the ATRA-ATO versus ATRA-CHT arms were 97.3% v 80%, 1.9% v 13.9%, and 99.2% v 92.6%, respectively ( P < .001, P = .0013, and P = .0073, respectively). Postinduction events included two relapses and one death in CR in the ATRA-ATO arm and two instances of molecular resistance after third consolidation, 15 relapses, and five deaths in CR in the ATRA-CHT arm. Two patients in the ATRA-CHT arm developed a therapy-related myeloid neoplasm.

Conclusion

These results show that the advantages of ATRA-ATO over ATRA-CHT increase over time and that there is significantly greater and more sustained antileukemic efficacy of ATO-ATRA compared with ATRA-CHT in low- and intermediate-risk APL.

The Phosphatases STS1 and STS2 Regulate Hematopoietic Stem and Progenitor Cell Fitness

FLT3 and c-KIT are crucial regulators of hematopoietic stem and progenitor cells. We investigated the role of STS1 and STS2 on FLT3 and c-KIT phosphorylation, activity, and function in normal and stress-induced hematopoiesis. STS1/STS2-deficient mice show a profound expansion of multipotent progenitor and lymphoid primed multipotent progenitor cells with elevated colony-forming capacity. Although long-term hematopoietic stem cells are not increased in numbers, lack of STS1 and STS2 significantly promotes long-term repopulation activity, demonstrating a pivotal role of STS1/STS2 in regulating hematopoietic stem and progenitor cell fitness. Biochemical analysis identified STS1/STS2 as direct phosphatases of FLT3 and c-KIT. Loss of STS1/STS2 induces hyperphosphorylation of FLT3, enhances AKT signaling, and confers a strong proliferative advantage. Therefore, our study reveals that STS1 and STS2 may serve as novel pharmaceutical targets to improve hematopoietic recovery after bone marrow transplantation.

Retinoic acid and arsenic trioxide for acute promyelocytic leukemia

BACKGROUND

All-trans retinoic acid (ATRA) with chemotherapy is the standard of care for acute promyelocytic leukemia (APL), resulting in cure rates exceeding 80%. Pilot studies of treatment with arsenic trioxide with or without ATRA have shown high efficacy and reduced hematologic toxicity.

METHODS

We conducted a phase 3, multicenter trial comparing ATRA plus chemotherapy with ATRA plus arsenic trioxide in patients with APL classified as low-to-intermediate risk (white-cell count, ≤10×10(9) per liter). Patients were randomly assigned to receive either ATRA plus arsenic trioxide for induction and consolidation therapy or standard ATRA-idarubicin induction therapy followed by three cycles of consolidation therapy with ATRA plus chemotherapy and maintenance therapy with low-dose chemotherapy and ATRA. The study was designed as a noninferiority trial to show that the difference between the rates of event-free survival at 2 years in the two groups was not greater than 5%.

RESULTS

Complete remission was achieved in all 77 patients in the ATRA-arsenic trioxide group who could be evaluated (100%) and in 75 of 79 patients in the ATRA-chemotherapy group (95%) (P=0.12). The median follow-up was 34.4 months. Two-year event-free survival rates were 97% in the ATRA-arsenic trioxide group and 86% in the ATRA-chemotherapy group (95% confidence interval for the difference, 2 to 22 percentage points; P<0.001 for noninferiority and P=0.02 for superiority of ATRA-arsenic trioxide). Overall survival was also better with ATRA-arsenic trioxide (P=0.02). As compared with ATRA-chemotherapy, ATRA-arsenic trioxide was associated with less hematologic toxicity and fewer infections but with more hepatic toxicity.

CONCLUSIONS

ATRA plus arsenic trioxide is at least not inferior and may be superior to ATRA plus chemotherapy in the treatment of patients with low-to-intermediate-risk APL. (Funded by Associazione Italiana contro le Leucemie and others; ClinicalTrials.gov number, NCT00482833.).

Interferon-γ impairs proliferation of hematopoietic stem cells in mice

Balancing the processes of hematopoietic stem cell (HSC) differentiation and self-renewal is critical for maintaining a lifelong supply of blood cells. The bone marrow (BM) produces a stable output of newly generated cells, but immunologic stress conditions inducing leukopenia increase the demand for peripheral blood cell supply. Here we demonstrate that the proinflammatory cytokine interferon-γ (IFN-γ) impairs maintenance of HSCs by directly reducing their proliferative capacity and that IFN-γ impairs restoration of HSC numbers upon viral infection. We show that IFN-γ reduces thrombopoietin (TPO)-mediated phosphorylation of signal transducer and activator of transcription (STAT) 5, an important positive regulator of HSC self-renewal. IFN-γ also induced expression of suppressor of cytokine signaling (SOCS) 1 in HSCs, and we demonstrate that SOCS1 expression is sufficient to inhibit TPO-induced STAT5 phosphorylation. Furthermore, IFN-γ deregulates expression of STAT5-mediated cell-cycle genes cyclin D1 and p57. These findings suggest that IFN-γ is a negative modulator of HSC self-renewal by modifying cytokine responses and expression of genes involved in HSC proliferation. We postulate that the occurrence of BM failure in chronic inflammatory conditions, such as aplastic anemia, HIV, and graft-versus-host disease, is related to a sustained impairment of HSC self-renewal caused by chronic IFN-γ signaling in these disorders.

Adjuvant therapy for resectable high-risk soft tissue sarcoma: feasibility and efficacy of a sandwich chemoradiotherapy strategy

PURPOSE

Radical definitive surgery is the only curative treatment approach in resectable soft tissue sarcoma. Despite complete resection, patients with grade 2 and 3 soft tissue sarcoma are at high risk of local or distant recurrence. Local and systemic adjuvant treatment includes radiotherapy and chemotherapy, but the optimal scheduling is not known.

METHODS

In this phase II clinical trial, we combined surgery with adjuvant chemotherapy and radiotherapy in a novel trimodality treatment sequence. Two to 6 weeks after surgery, patients received 2 cycles of chemotherapy containing doxorubicin and ifosfamide, then 50.4 Gy of percutaneous radiotherapy followed by additional 2 cycles of chemotherapy.

RESULTS

Chemotherapy and radiotherapy-related toxicity was generally mild, without treatment delays in the majority of patients. After a median follow-up of 57 months, 81.5% of patients are alive in complete remission.

CONCLUSIONS

The sandwich chemoradiation protocol proved to be feasible with manageable toxicity. The patient outcome compared favorably with other adjuvant trials in preventing relapse, particularly distant relapse which is predictive of poor outcome. This multidisciplinary approach warrants further investigation in a larger randomized trial.

Adaptor protein Lnk binds to PDGF receptor and inhibits PDGF-dependent signaling

OBJECTIVE

Platelet-derived growth factor receptors α and β (PDGFRA, PDGFRB) are frequently expressed on hematopoietic cells and regulate cellular responses such as proliferation, differentiation, survival, and transformation. Stimulation by autocrine loops or activation by chromosomal translocation makes them important factors in development of hematopoietic disorders. Interaction with the ligand PDGF results in activation of the tyrosine kinase domain and phosphorylation of tyrosine residues, thereby creating binding sites for molecules containing Src homology 2 domains. We hypothesized that one such protein may be Lnk, a negative regulator of cytokine receptors, including Mpl, EpoR, c-Kit, and c-Fms.

MATERIALS AND METHODS

Interaction of Lnk with PDGFRA, PDGFRB, or leukemogenic FIP1L1-PDGFRA or TEL-PDGFRB was studied in cotransfected 293T cells. Effects of Lnk on PDGFR signaling were shown in 293T and NIH3T3 cells, whereas its influence on either PDGF-dependent or factor-independent growth was investigated using Ba/F3 or 32D cells expressing wild-type PDGFR, FIP1L1-PDGFRA, or TEL-PDGFRB.

RESULTS

We show that Lnk binds to PDGFR after exposure of cells to PDGF. Furthermore, Lnk can bind the FIP1L1-PDGFRA fusion protein. Mutation or deletion of the Lnk Src homology 2 domain completely abolished binding of Lnk to FIP1L1-PDGFRA, but just partly prevented binding to PDGFRA or PDGFRB. Expression of Lnk inhibited proliferation of PDGF-dependent Ba/F3 cells and diminished phosphorylation of Erk in PDGF-treated NIH3T3. 32D cells transformed by either FIP1L1-PDGFRA or TEL-PDGFRB stopped growing when Lnk was expressed.

CONCLUSIONS

Lnk is a negative regulator of PDGFR signaling. Development of Lnk mimetic drugs might provide a novel therapeutic strategy for myeloproliferative disorders.

Adaptor protein Lnk inhibits c-Fms-mediated macrophage function

The M-CSFR (c-Fms) participates in proliferation, differentiation, and survival of macrophages and is involved in the regulation of distinct macrophage functions. Interaction with the ligand M-CSF results in phosphorylation of tyrosine residues on c-Fms, thereby creating binding sites for molecules containing SH2 domains. Lnk is a SH2 domain adaptor protein that negatively regulates hematopoietic cytokine receptors. Here, we show that Lnk binds to c-Fms. Biological and functional effects of this interaction were examined in macrophages from Lnk-deficient (KO) and WT mice. Clonogenic assays demonstrated an elevated number of M-CFUs in the bone marrow of Lnk KO mice. Furthermore, the M-CSF-induced phosphorylation of Akt in Lnk KO macrophages was increased and prolonged, whereas phosphorylation of Erk was diminished. Zymosan-stimulated production of ROS was increased dramatically in a M-CSF-dependent manner in Lnk KO macrophages. Lastly, Lnk inhibited M-CSF-induced migration of macrophages. In summary, we show that Lnk binds to c-Fms and can blunt M-CSF stimulation. Modulation of levels of Lnk in macrophages may provide a unique therapeutic approach to increase innate host defenses.

Oncogenic signaling in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant disease of the bone marrow. Despite intensive treatment only one third of AML patients are cured. Numerous genetic events have been identified in the last years that have shed light into the mechanisms dictating increased self-renewal, proliferation, survival and block in differentiation. It is increasingly recognized that AML represents a hierarchical disease, originating from a leukemia stem cell population. Sophisticated animal models have helped to elucidate rate-limiting steps in initiation, development and maintenance of AML. This review discusses the fundamental genetic events identified to date that determine the pathogenesis of AML, with particular emphasis on the oncogenic signaling events that result from translocation of myeloid transcription factors and mutations in receptor tyrosine kinases. Our current understanding of the biology of AML has fueled the development of promising anti-leukemic agents, which may improve the treatment of the disease in the future.

Constitutive activation of Akt by Flt3 internal tandem duplications is necessary for increased survival, proliferation, and myeloid transformation

Up to 30% of patients with acute myeloid leukemia (AML) harbor internal tandem duplications (ITD) within the FLT3 gene, encoding a receptor tyrosine kinase. These mutations induce constitutive tyrosine kinase activity in the absence of the natural Flt3 ligand and confer growth factor independence, increased proliferation, and survival to myeloid precursor cells. The signaling pathways and downstream nuclear targets mediating leukemic transformation are only partly identified. Here, we show that the presence of Flt3-ITD constitutively activates Akt (PKB), a key serine-threonine kinase within the phosphatidylinositol 3-kinase pathway. Constitutive activation of Akt phosphorylated and inhibited the transcription factor Foxo3a. Restored Foxo3a activity reversed Flt3-ITD-mediated growth properties and dominant-negative Akt prevented Flt3-ITD-mediated cytokine independence. Conditional Akt activation targeted to the cell membrane induced cytokine-independent survival, cell cycle progression, and proliferation. Importantly, Akt activation was sufficient to cause in vitro transformation of 32D myeloid progenitor cells and in vivo promoted the development of a leukemia-like myeloid disease. Akt phosphorylation was found in myeloid blasts of 86% of AML patients, suggesting an important role in leukemogenesis. In summary, Akt is necessary for increased survival, proliferation, and leukemic transformation by Flt3-ITD, possibly by inactivation of Foxo transcription factors. These findings indicate that Akt and Foxo transcription factors are attractive targets for therapeutic intervention in AML.

Identification of metastasis-associated receptor tyrosine kinases in non-small cell lung cancer

Development of distant metastasis after tumor resection is the leading cause of death in early-stage non-small cell lung cancer (NSCLC). Receptor tyrosine kinases (RTK) are involved in tumorigenesis but only few RTKs have been systematically studied in NSCLC. Here, we provide quantitative real-time reverse transcription-PCR expression data of all RTKs (n=56) in primary tumors of 70 patients with early-stage (I-IIIA) NSCLC. Overall, 33 RTKs were expressed in at least 25% of the patients. Several RTKs were significantly expressed higher in tumors that ultimately metastasized. The hazard risk for metastasis development in stage I/II disease was increased at least 3-fold for tumors with high expression levels of insulin receptor, neurotrophic tyrosine receptor kinase 1, epidermal growth factor receptor, ERBB2, ERBB3, platelet-derived growth factor receptor beta, fibroblast growth factor receptor 1, or leukocyte tyrosine kinase. Relative risks were reduced 3-fold by expression of EPHB6 or DKFZ1. Three members of the epidermal growth factor receptor family were associated with a high risk of metastasis, emphasizing the validity of our data. High ERBB3 expression was significantly associated with decreased survival. Taken together, our genome-wide RTK expression map uncovered the previously unknown value of several RTKs as potential markers for prognosis and metastasis prediction in early-stage NSCLC. The identified RTKs represent promising novel candidates for further functional analyses.

Phosphorylation-independent stabilization of p27kip1 by the phosphoinositide 3-kinase pathway in glioblastoma cells

The PTEN tumor suppressor gene is a frequent target of somatic mutation, particularly in glioblastoma multiform and prostate cancer. The expression of PTEN in PTEN-mutant glioblastoma cells leads to a cell cycle arrest in G(0)/G(1) that is mediated at least partially by increased p27(kip1) levels. Here we show that p27(kip1) is not regulated by transcriptional control but that p27(kip1) protein shows increased stability after inhibition of the phosphoinositide (PI) 3-kinase pathway. Because p27(kip1) protein stability is known to be regulated by phosphorylation, we have examined modifications in the phosphorylation pattern after PI 3-kinase inhibition. Biochemical evidence suggests that p27(kip1) is phosphorylated on several serine residues, including Ser-10 and Ser-178, but that phosphorylation is unaltered by PI 3-kinase activity. This is further confirmed by the inducible expression of p27(kip1) phosphorylation site mutants, suggesting that p27(kip1) is destabilized in a phosphorylation-independent manner by the PI 3-kinase pathway at the G(1)/S transition.

Oncolytic viruses for the treatment of cancer: current strategies and clinical trials

Tumor-selective replicating viruses offer appealing advantages over conventional cancer therapy and are a promising new approach for the treatment of human cancer. The development of virotherapeutics is based on several strategies that each provides a different foundation for tumor-selective targeting and replication. Results emerging from clinical trials with oncolytic viruses demonstrate the safety and feasibility of a virotherapeutic approach and provide early indications of efficacy. Strategies to overcome potential obstacles and challenges to virotherapy are currently being explored and are discussed here. Importantly, the successful development of systemic administration of oncolytic viruses will extend the range of tumors that can be treated using this novel treatment modality.

Replication-selective viruses for cancer therapy

Advances in our understanding of the molecular basis of cancer and the availability of technology to genetically engineer viruses have led to the development of replication-competent viruses to treat cancer. In theory, replication-selective viruses offer several appealing properties as biological agents for cancer therapy: they kill tumor cells selectively, and their replication leads to amplification of their oncolytic potential. Most preclinical experiments in tissue culture and in animal models support this notion. Clinical data on the first generation of replication-selective viruses are now rapidly accruing. The therapeutic index, and ultimately the clinical outcome, will depend on a complex balance between host and viral factors. This review discusses strategies to kill cancer cells based on our understanding of their molecular defects and the progress being made using replication-competent viruses for tumor therapy. We focus our discussion on a replication-selective adenovirus called ONYX-015 that has recently demonstrated encouraging results in clinical trials

Topical transforming growth factor-beta3 in the prevention or alleviation of chemotherapy-induced oral mucositis in patients with lymphomas or solid tumors

Transforming growth factor (TGF)-beta3 has been hypothesized to prevent or alleviate oral mucositis (OM) in cancer patients receiving high-dose chemotherapy (CT). Two double-blind, placebo-controlled, multicenter, phase II studies of TGF-beta3 were initiated in the United States, Europe, and Argentina in patients with lymphomas or solid tumors who were receiving highly stomatotoxic CT regimens. Patients were to apply 10-mL mouthwash applications of TGF-beta3 (25 microg/mL) or placebo four times daily (or twice daily) 1 day before and all days during CT. The patients were subsequently evaluated for OM incidence, severity, and duration using National Institute of Cancer Common Toxicity Criteria (NCI-CTC) criteria and an objective scoring system (1). After the start of the trials, negative results from new preclinical studies suggesting suboptimal formulation and/or dosing led to an interim analysis of the ongoing clinical trials. One hundred fifty-two patients from the combined studies were included in the interim analysis, with 116 patients on the TGF-beta3 four times daily and placebo arms. Most (72%) patients had breast cancer, 22% had lymphomas, and 6% had other solid tumors. Although 98% (149 of 152) of patients experienced adverse events, only 14% (22 of 152) experienced events that were judged as possibly or probably related to the study drug (primarily gastrointestinal symptoms). No clinically relevant differences were seen between the treatment and placebo arms regarding safety, nor was there evidence for systemic absorption of TGF-beta3. Finally, there was no advantage of TGF-beta3 treatment regarding the incidence (TGF-beta3 four times daily versus placebo [46% versus 47%]), onset, or duration of NCI-CTC grade 3 or 4 OM. For this dose, formulation, regimen. and patient population, TGF-beta3 was not effective in the prevention or alleviation of CT-induced OM.

p27Kip1 is required for PTEN-induced G1 growth arrest

The tumor suppressor PTEN is one of the most commonly inactivated genes in human cancer. Glioblastoma multiforme cells harboring mutant PTEN have abnormally high levels of 3' phosphoinositides and elevated protein kinase B activity. Expression of wild-type PTEN in glioma cells, containing endogenous mutant PTEN, reduces 3' phosphoinositides levels, inhibits PKB activity, and induces G1 cell cycle arrest. We investigated the mechanism of the PTEN-induced growth arrest in glioma cell lines. Expression of PTEN is associated with increased expression of p27Kip1, decreased expression of cyclins A and D3, inhibition of cdk2 activity, and dephosphorylation of pRb. Inactivation of p53, by the human papilloma virus E6 oncoprotein, does not prevent PTEN-induced G1 arrest, implying that p53 is not required for G1 arrest. In contrast, p27Kip1 antisense oligonucleotides abrogated the growth arrest induced by PTEN. Furthermore, blocking p27Kip1 expression prevented the PTEN-induced reduction of cyclin-dependent kinase 2 activity, indicating that p27Kip1 functions upstream of cyclin-dependent kinase 2 in the PTEN regulatory cascade. These results implicate p27Kip1 as a critical mediator of PTEN-induced G1 arrest.

The circadian rhythm of body temperature is preserved during malarial fever

Body temperature follows a circadian rhythm with a low around 6 a.m. and a peak about 12 hours later. The effect of fever on this endogenous oscillation is unknown. We obtained hourly measurements of the rectal temperature of 66 children with Plasmodium falciparum malaria. Even at febrile temperatures, the temperature followed a clear circadian rhythm. 33 patients (50%) had fever above 38 degrees C at 6 p.m. on the first day compared to only 9 (14%) at 6 a.m. the next morning. This considerable difference was also found on the second day of observation. Since in clinical practice antipyretics are often given above a certain fever threshold, the time of day should be taken into account when antipyretics are applied.

Loss of p14ARF in tumor cells facilitates replication of the adenovirus mutant dl1520 (ONYX-015)

The adenovirus mutant dl1520 (ONYX-015) does not express the E1B-55K protein that binds and inactivates p53. This virus replicates in tumor cells with mutant p53, but not in normal cells with functional p53. Although intra-tumoral injection of dl1520 shows promising responses in patients with solid tumors, previous in vitro studies have not established a close correlation between p53 status and dl1520 replication. Here we identify loss of p14ARF as a mechanism that allows dl1520 replication in tumor cells retaining wild-type p53. We demonstrate that the re-introduction of p14ARF into tumor cells with wild-type p53 suppresses replication of dl1520 in a p53-dependent manner. Our study supports the therapeutic use of dl1520 in tumors with lesions within the p53 pathway other than mutation of p53.

Effect of paracetamol on parasite clearance time in Plasmodium falciparum malaria

BACKGROUND

Routine antipyretic therapy in children with infectious diseases has long been the source of controversy. Each year, in addition to antimalarial medication, millions of children with Plasmodium falciparum malaria receive paracetamol to reduce fever. However, the usefulness of this practice has not been proven.

METHODS

In a randomised trial in Lambaréné, Gabon, 50 children with P falciparum malaria were treated with intravenous quinine, and received either mechanical antipyresis alone, or in combination with paracetamol. Rectal body temperature and parasitaemia were recorded every 6 h for 4 days. Plasma concentrations and inducible concentrations of tumour necrosis factor (TNF) and interleukin-6 were measured every 24 h. In addition, production of oxygen radicals was measured in both groups.

FINDINGS

The mean fever clearance time was 32 h for children treated with paracetamol and 43 h for those who received mechanical antipyresis alone; however, this 11 h difference was not significant (95% CI -2 to 24 h; p = 0.176). Parasite clearance time was significantly prolonged in patients who received paracetamol with a difference of 16 h (8-24 h; p = 0.004). Plasma concentrations of TNF and interleukin-6 were similar in both groups during the study. However, the induced concentrations of TNF, and the production of oxygen radicals, were significantly lower in children treated with paracetamol than those who received mechanical antipyresis alone.

INTERPRETATION

These data suggest that paracetamol has no antipyretic benefits over mechanical antipyresis alone in P falciparum malaria. Moreover, paracetamol prolongs parasite clearance time, possibly by decreased production of TNF and oxygen radicals.

[The dual role of tumor necrosis factor (TNF) during a malarial attack]

The roles of the various factors implicated in the pathogenesis of severe malaria are not well understood. Tumor necrosis factor (TNF), a cytokine produced mainly by macrophages, seems to play a crucial role in both the host's defence against the parasite and the development of severe complications. This review investigates the dual role of TNF in acute malaria, summarizing current knowledge of the beneficial and detrimental effects of this molecule. Recent work has suggested a possible explanation for this dualism, involving a complex interaction between TNF and its soluble receptors.