Safety and preliminary activity results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab in patients with refractory solid tumors.

BACKGROUND: The phase I GATTO study (NCT03360734) explored the feasibility, tolerability and preliminary activity of combining gatipotuzumab, a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin 1 (TA-MUC1) and an anti-epidermal growth factor receptor (anti-EGFR) antibody in refractory solid tumors. PATIENTS AND METHODS: Initially the study enrolled primary phase (PP) patients with EGFR-positive metastatic solid tumors, for whom no standard treatment was available. Patients received gatipotuzumab administered at 1400 mg every 2 weeks, 6 weeks after the start of the glyco-optimized anti-EGFR antibody tomuzotuximab at 1200 mg every 2 weeks. As this regimen was proven safe, enrollment continued in an expansion phase (EP) of patients with refractory metastatic colorectal cancer, non-small-cell lung cancer, head and neck cancer and breast cancer. Tomuzotuximab and gatipotuzumab were given at the same doses and gatipotuzumab treatment started 1 week after the first dose of the anti-EGFR antibody. Additionally, investigators could use a commercial anti-EGFR antibody in place of tomuzotuximab. RESULTS: A total of 52 patients were enrolled, 20 in the PP and 32 in the EP. The combined treatment was well tolerated and no dose-limiting toxicity was observed in the whole study, nor related serious adverse event or death. Preliminary activity of the combination was observed, with one and four RECIST partial responses in the PP and EP, all in colorectal cancer patients. The trial was accompanied by a comprehensive translational research program for identification of biomarkers, including soluble TA-MUC1 (sTA-MUC1) in serum. In the EP, patients with baseline sTA-MUC1 levels above the median appeared to have improved progression-free survival and overall survival. CONCLUSIONS: Combination of a TA-MUC1-targeting antibody and an EGFR-targeting antibody is safe and feasible. Interesting antitumor activity was observed in heavily pretreated patients. Future studies should test this combination together with chemotherapy and explore the potential of sTA-MUC1 as a companion biomarker for further development of the combination.

Increased frequency of TIGIT+CD73-CD8+ T cells with a TOX+ TCF-1low profile in patients with newly diagnosed and relapsed AML.

The inhibitory receptor TIGIT, as well as theectonucleotidases CD39 and CD73 constitute potential exhaustion markers for T cells. Detailed analysis of these markers can shed light into dysregulation of the T-cell response in acute myeloid leukemia (AML) and will help to identify potential therapeutic targets.  The phenotype and expression of transcription factors was assessed on different T-cell populations derived from peripheral blood (PB, n = 38) and bone marrow (BM, n = 43). PB and BM from patients with AML diagnosis, in remission and at relapse were compared with PB from healthy volunteers (HD) (n = 12) using multiparameter flow cytometry. An increased frequency of terminally differentiated (CD45R-CCR7-)CD8+ T cells was detected in PB and BM regardless of the disease state. Moreover, we detected an increased frequency of two distinct T-cell populations characterized by the co-expression of PD-1 or CD39 on TIGIT+CD73-CD8+ T cells in newly diagnosed and relapsed AML in comparison to HDs. In contrast to the PD-1+TIGIT+CD73-CD8+ T-cell population, the frequency of CD39+TIGIT+CD73-CD8+ T cells was normalized in remission. PD-1+- and CD39+TIGIT+CD73-CD8+ T cells exhibited additional features of exhaustion by decreased expression of CD127 and TCF-1 and increased intracellular expression of the transcription factor TOX. CD8+ T cells in AML exhibit a key signature of two subpopulations, PD-1+TOX+TIGIT+CD73-CD8+- and CD39+TOX+TIGIT+CD73-CD8+ T cells that were increased at different stages of the disease. These results provide a rationale to analyze TIGIT blockade in combination with inhibition of the purinergic signaling and depletion of TOX to improve T-cell mediated cytotoxicity in AML. Abbreviations: AML: Acute myeloid leukemia; pAML: newly diagnosed AML; rAML: relapse AML; lrAML: AML in remission; HD: healthy donor; PB: peripheral blood; BM: bone marrow; TIGIT: T-cell immunoreceptor with Ig and ITIM domains; PD-1: Programmed cell death protein 1; CD73: ecto-5'-nucleotidase; CD39: ectonucleoside triphosphate diphosphohydrolase 1; ATP: adenosine triphosphate; ADO: adenosine; CD127: interleukin-7 receptor; CAR-T cell: chimeric antigen receptor T cell; TCF-1: transcription factor T-cell factor 1; TOX: Thymocyte selection-associated high mobility group box protein; NFAT: nuclear factor of activated T cells; NA: Naïve; CM: Central Memory; EM Effector Memory; EMRA: Terminal Effector Memory cells; FMO: Fluorescence minus one; PVR: poliovirus receptor; PVRL2: poliovirus receptor-related 2; IFN-γ: Interferon-γ; IL-2: interleukin-2; MCF: multiparametric flow cytometry; TNFα: Tumornekrosefaktor α; RT: room temperature.

Correction: Role of growth arrest-specific gene 6-mer axis in multiple myeloma.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

DNMT3A mutant transcript levels persist in remission and do not predict outcome in patients with acute myeloid leukemia.

We investigated the prognostic impact of minimal residual disease (MRD) monitoring in acute myeloid leukemia patients harboring DNA methyltransferase 3A-R882H/-R882C mutations (DNMT3Amut). MRD was determined by real-time quantitative PCR (RQ-PCR) in 1494 samples of 181 DNMT3Amut patients. At the time of diagnosis, DNMT3Amut transcript levels did not correlate with presenting clinical characteristics and concurrent gene mutations as well as the survival end points. In Cox regression analyses, bone marrow (BM) DNMT3Amut transcript levels (log10-transformed continuous variable) were not associated with the rate of relapse or death. DNMT3Amut transcript levels were significantly higher in BM than in blood after induction I (P=0.01), induction II (P=0.05), consolidation I (P=0.004) and consolidation II (P=0.008). With regard to the clinically relevant MRD time points, after two cycles of induction and at the end of therapy, DNMT3Amut transcript levels had no impact on the end point remission duration and overall survival. Of note, only a minority of the patients achieved RQ-PCR negativity, whereas most had constantly high DNMT3Amut transcript levels, a finding which is consistent with the persistence of clonal hematopoiesis in hematological remission.

Epidemiological, genetic, and clinical characterization by age of newly diagnosed acute myeloid leukemia based on an academic population-based registry study (AMLSG BiO).

We describe genetic and clinical characteristics of acute myeloid leukemia (AML) patients according to age from an academic population-based registry. Adult patients with newly diagnosed AML at 63 centers in Germany and Austria were followed within the AMLSG BiO registry (NCT01252485). Between January 1, 2012, and December 31, 2014, data of 3525 patients with AML (45% women) were collected. The median age was 65 years (range 18-94). The comparison of age-specific AML incidence rates with epidemiological cancer registries revealed excellent coverage in patients < 70 years old and good coverage up to the age of 80. The distribution according to the European LeukemiaNet (ELN) risk categorization from 2010 was 20% favorable, 31% intermediate-1, 28% intermediate-2, and 21% adverse. With increasing age, the relative but not the absolute prevalence of patients with ELN favorable and intermediate-1 risk (p < 0.001), with activating FLT3 mutations (p < 0.001), with ECOG performance status < 2 (p < 0.001), and with HCT-CI comorbidity index < 3 (p < 0.001) decreased. Regarding treatment, obesity and favorable risk were associated with an intensive treatment, whereas adverse risk, higher age, and comorbidity index > 0 were associated with non-intensive treatment or best supportive care. The AMLSG BiO registry provides reliable population-based distributions of genetic, clinical, and treatment characteristics according to age.

SHIP1, but not an AML-derived SHIP1 mutant, suppresses myeloid leukemia growth in a xenotransplantation mouse model.

Constitutive activation of the PI3K/AKT signaling pathway is found in ~50-70% of AML patients. The SH2-containing inositol 5-phosphatase 1 (SHIP1) is a negative regulator of PI3K/AKT signaling in hematopoietic cells. SHIP1 knockout mice develop a myeloproliferative syndrome and concomitant deletion of SHIP1 and the tumor suppressor PTEN leads to the development of lethal B-cell lymphomas. In the study presented here, we investigated the role of SHIP1 as a tumor suppressor in myeloid leukemia cells in an in vivo xenograft transplantation model. NSG Mice transplanted with UKE-1 cells derived from a secondary AML showed a significantly extended lifespan after lentiviral-mediated overexpression of SHIP1 in comparison to the vector control cohort. In contrast, the AML-derived SHIP1Y643H mutant, which has a strongly reduced enzymatic activity showed a significant reversion of the SHIP1-induced prolongation of the survival time. In addition, the analysis of 290 AML patients revealed a correlation between expression of SHIP1 and overall survival of the AML patients. These results indicate that SHIP1 can act as a tumor suppressor in acute myeloid leukemia cells and that higher SHIP1 expression is associated with prolonged overall survival in AML patients. SHIP1 may be an interesting candidate for gene therapy.

Condensed versus standard schedule of high-dose cytarabine consolidation therapy with pegfilgrastim growth factor support in acute myeloid leukemia.

The aim of this cohort study was to compare a condensed schedule of consolidation therapy with high-dose cytarabine on days 1, 2 and 3 (HDAC-123) with the HDAC schedule given on days 1, 3 and 5 (HDAC-135) as well as to evaluate the prophylactic use of pegfilgrastim after chemotherapy in younger patients with acute myeloid leukemia in first complete remission. One hundred and seventy-six patients were treated with HDAC-135 and 392 patients with HDAC-123 with prophylactic pegfilgrastim at days 10 and 8, respectively, in the AMLSG 07-04 and the German AML Intergroup protocol. Time from start to chemotherapy until hematologic recovery with white blood cells >1.0 G/l and neutrophils >0.5 G/l was in median 4 days shorter in patients receiving HDAC-123 compared with HDAC-135 (P<0.0001, each), and further reduced by 2 days (P<0.0001) by pegfilgrastim. Rates of infections were reduced by HDAC-123 (P<0.0001) and pegfilgrastim (P=0.002). Days in hospital and platelet transfusions were significantly reduced by HDAC-123 compared with HDAC-135. Survival was neither affected by HDAC-123 versus HDAC-135 nor by pegfilgrastim. In conclusion, consolidation therapy with HDAC-123 leads to faster hematologic recovery and less infections, platelet transfusions as well as days in hospital without affecting survival.

Acute myeloid leukemia derived from lympho-myeloid clonal hematopoiesis.

We studied acute myeloid leukemia (AML) patients with lympho-myeloid clonal hematopoiesis (LM-CH), defined by the presence of DNA methyltransferase 3A (DNMT3A) mutations in both the myeloid and lymphoid T-cell compartment. Diagnostic, complete remission (CR) and relapse samples were sequenced for 34 leukemia-related genes in 171 DNMT3A mutated adult AML patients. AML with LM-CH was found in 40 patients (23%) and was associated with clonal hematopoiesis of indeterminate potential years before AML, older age, secondary AML and more frequent MDS-type co-mutations (TET2, RUNX1 and EZH2). In 82% of AML patients with LM-CH, the preleukemic clone was refractory to chemotherapy and was the founding clone for relapse. Both LM-CH and non-LM-CH MRD-positive AML patients who achieved CR had a high risk of relapse after 10 years (75% and 75%, respectively) compared with patients without clonal hematopoiesis in CR with negative MRD (27% relapse rate). Long-term survival of patients with LM-CH was only seen after allogeneic hematopoietic stem cell transplantation (HSCT). We define AML patients with LM-CH as a distinct high-risk group of AML patients that can be identified at diagnosis through mutation analysis in T cells and should be considered for HSCT.

A phase I study of PankoMab-GEX, a humanised glyco-optimised monoclonal antibody to a novel tumour-specific MUC1 glycopeptide epitope in patients with advanced carcinomas.

BACKGROUND: A phase I open-label dose-escalation study was conducted to define the safety, tolerability, and pharmacokinetics (PK) of PankoMab-GEX, a glyco-optimised humanised IgG1, with high affinity to a novel tumour-specific glycopeptide epitope of MUC1 (TA-MUC1) with excellent preclinical anti-tumour activity. PATIENTS AND METHODS: Seventy-four patients with advanced TA-MUC1-positive carcinomas received PankoMab-GEX intravenously every 3 (Q3W), 2 (Q2W), or 1 (QW) week in doses of 1-2200 mg in a three-plus-three dose-escalation design until disease progression (NCT01222624). RESULTS: No maximum tolerated dose was reached. Adverse events were mainly mild-to-moderate infusion-related reactions (IRRs) by the first infusion in 45% of patients. Only one dose-limiting toxicity, a grade III IRR, was observed. PankoMab-GEX exhibited linear PK over all doses. Mean terminal half-life was 189 ± 66 h (Q3W), without dose dependency. A target trough level ≥50 µg/mL was reached after one infusion with doses ≥1700 mg Q3W in 80% of patients. Clinical benefit in 60 evaluable patients included one complete response in a patient with ovarian cancer treated 483 d and confirmed disease stabilisation in 19 patients lasting a median (range) of 23 (10-109) weeks. All but two of the patients with clinical benefit had received a compounded total dose ≥700 mg over a 3-week period, including 8 of 12 (67%) patients with ovarian cancer. CONCLUSION: PankoMab-GEX is safe, well tolerated, and showed promising anti-tumour activity in advanced disease. A phase IIb study is ongoing evaluating the efficacy of PankoMab-GEX as a maintenance therapy in advanced ovarian cancer.

Role of Growth arrest-specific gene 6-Mer axis in multiple myeloma.

Multiple myeloma is a mostly incurable malignancy characterized by the expansion of a malignant plasma cell (PC) clone in the human bone marrow (BM). Myeloma cells closely interact with the BM stroma, which secretes soluble factors that foster myeloma progression and therapy resistance. Growth arrest-specific gene 6 (Gas6) is produced by BM-derived stroma cells and can promote malignancy. However, the role of Gas6 and its receptors Axl, Tyro3 and Mer (TAM receptors) in myeloma is unknown. We therefore investigated their expression in myeloma cell lines and in the BM of myeloma patients and healthy donors. Gas6 showed increased expression in sorted BMPCs of myeloma patients compared with healthy controls. The fraction of Mer(+) BMPCs was increased in myeloma patients in comparison with healthy controls whereas Axl and Tyro3 were not expressed by BMPCs in the majority of patients. Downregulation of Gas6 and Mer inhibited the proliferation of different myeloma cell lines, whereas knocking down Axl or Tyro3 had no effect. Inhibition of the Gas6 receptor Mer or therapeutic targeting of Gas6 by warfarin reduced myeloma burden and improved survival in a systemic model of myeloma. Thus, the Gas6-Mer axis represents a novel candidate for therapeutic intervention in this incurable malignancy.

Clinical experience with antiangiogenic therapy in leukemia.

The pathological role of bone marrow angiogenesis in human leukemias has been clearly established. Bone marrow neoangiogenesis is mediated by several growth factors, such as VEGF-A, VEGF-C, angiopoietin-1 and -2, FGF, HGF, TGF-ß and others secreted by leukemic cells. The prognostic relevance of microvessel density, and expression of VEGF-A and -C has been demonstrated especially in acute myeloid leukemia. In the last years, several classes of angiogenesis inhibitors have been developed blocking several angiogenic pathways. These include drugs that inhibit the VEGF (with or without blockade of FLT3) and the mTor signalling cascade. Besides, thalidomide and lenalidomide although possessing a pleiotrophic mode of action including antiangiogenic properities have been evaluated in the treatment of human leukemias. In the current review we analyze the results of clinical trials employing these antiangiogenic drugs. Since the clinical efficacy of these compounds used as monotherapy is often limited, confined to certain subgroups of patients and frequently short lived, several trials combining standard chemotherapy with these agents have been initiated in order to demonstrate an additional benefit to standard therapy. Furthermore the introduction of new antiangiogenic drugs such as inhibitors of the angiopoietin and HGF/cMET pathway is on the horizon. Utilizing cocktails of inhibitors of several angiogenic pathways may represent a new possibility to augment the efficacy of antiangiogenic therapy in the future.

Plerixafor is effective and safe for stem cell mobilization in heavily pretreated germ cell tumor patients.

Up to 10% of germ cell tumor patients require salvage high-dose chemotherapy with stem cell support, achieving cure rates in the range of 10-60%. Stem cell mobilization may be difficult in these patients because of multiple lines of treatment known to seriously hamper stem cell recovery. Plerixafor significantly enhances the success of the CD34+ cell harvest, even in cases where prior mobilization attempts have failed. Six germ cell tumor patients provided informed consent and were included in the compassionate use program. All patients were heavily pretreated, with a median of 3.5 prior lines of therapy. All failed prior mobilization with G-CSF in combination with chemotherapy. Five patients yielded a median of 2.6 × 10(6) CD34+ cells per kg body weight in a median of 4 apheresis days when plerixafor was used. Three patients underwent subsequent high-dose chemotherapy with autologous stem cell support. Median time to leukocyte engraftment was 11 days. Median time to platelet engraftment was 12.5 days, both of which are comparable to previous historical data. Accordingly, plerixafor seems to be safe and effective in germ cell tumor patients who have failed prior mobilization therapy. Larger prospective studies are warranted to further assess its use in germ cell cancer.

Phase I trial of SU14813 in patients with advanced solid malignancies.

BACKGROUND: this phase I, open-label, dose-escalation study investigated SU14813, an oral multitargeted tyrosine kinase inhibitor, in adults with solid tumors. PATIENTS AND METHODS: seventy-seven patients received once-daily SU14813, either for 4 weeks followed by 1 week off treatment (schedule 4/1) or continuously [continuous daily dosing (CDD)]. The primary end point was to determine the maximum tolerated dose (MTD). Safety, pharmacokinetics, pharmacodynamics, and efficacy were assessed. RESULTS: MTDs were 200 mg/day on schedule 4/1 and 100 mg/day with CDD. Adverse events included fatigue (64%), diarrhea (61%), nausea (44%), anorexia (43%), and vomiting (42%). SU14813 steady state was attained by day 8. Exposure increased in a generally dose-proportional manner and SU14813 was eliminated with a mean terminal half-life of 9-34 h. Target plasma concentrations (>100 ng/ml SU14813) were achieved and sustained over 12 h at ≥ 100 mg/day. Progression-free survival among the 1 complete responder and 12 partial responders was 1.4-53.2 months. Fifteen patients remained on treatment at 1 year and 3 patients at 2 years. CONCLUSION: SU14813 has manageable safety and tolerability and allows once-daily continuous oral dosing. SU14813 shows dose-proportional pharmacokinetics, with target plasma concentrations achieved at doses ≥ 100 mg/day. Clinically meaningful activity with durable responses was observed, meriting further study.

Transmission dynamics of highly pathogenic avian influenza at Lake Constance (Europe) during the outbreak of winter 2005-2006.

Highly pathogenic avian influenza virus (HPAI) H5N1 poses a serious threat to domestic animals. Despite the large number of studies on influenza A virus in waterbirds, little is still known about the transmission dynamics, including prevalence, behavior, and spread of these viruses in the wild waterbird population. From January to April 2006, the HPAI H5N1 virus was confirmed in 82 dead wild waterbirds at the shores of Lake Constance. In this study, we present simple mathematical models to examine this outbreak and to investigate the transmission dynamics of HPAI in wild waterbirds. The population dynamics model of wintering birds was best represented by a sinusoidal function. This model was considered the most adequate to represent the susceptible compartment of the SIR model. The three transmission models predict a basic reproduction ratio (R (0)) with value of approximately 1.6, indicating a small epidemic, which ended with the migration of susceptible wild waterbirds at the end of the winter. With this study, we quantify for the first time the transmission of HPAI H5N1 virus at Lake Constance during the outbreak of winter 2005-2006. It is a step toward the improvement of the knowledge of transmission of the virus among wild waterbirds.

[28-year old female patient with respiratory insufficiency, elevated liver enzymes, pancytopenia and fever]. / 28-jährige Patientin mit respiratorischer Insuffizienz, erhöhten Leberwerten, Fieber und Panzytopenie.

We report on a 28-year old female patient with fever and severe respiratory insufficiency requiring mechanical ventilation. Cytomegalovirus pneumonia was diagnosed by bronchoalveolar lavage, and antiviral therapy was initiated. However fever persisted and laboratory workup showed pancytopenia and elevated liver enzymes. Additional blood tests demonstrated a markedly elevated ferritin level and high concentrations of inflammatory cytokines. A diagnosis of hemophagocytic lymphohistiocytosis was made and immunosuppressive therapy was started. The patient's condition and laboratory values improved rapidly.