Michel A. Duchosal

Bevacizumab therapy before autologous stem-cell transplantation for POEMS syndrome

POEMS is an acronym for a rare multisystemic syndrome encompassing polyneuropathy (P), organomegaly (O), endocrinopathy (E), monoclonal gammopathy (M), skin changes (S) and additional features variably expressed [1]. POEMS syndrome is associated with high vascular endothelial growth factor (VEGF) serum levels. This angiogenic factor likely plays a pathogenic role, in particular for neuropathy, possibly via alteration of endoneurial vessels [2]. Treatment options are still debated, but recently autologous stem-cell transplantation (ASCT) appears to be effective. This approach for POEMS patients, however, was associated with severe morbidity, mainly respiratory failures that appeared to be related to neuromuscular damage [3]. We report a 45-year-old woman presenting with a rapidly progressive sensorimotor polyneuropathy involving all extremities, multiple sclerotic bone lesions, skin hyperpigmentation and hemangiomas, hepatomegaly, peripheral edema and papilledema. A monoclonal immunoglobulin A k protein was detected (5 g/l) with a bone marrow plasmocytosis (15%). Platelets were 600 · 10/l and cerebrospinal fluid proteins were 30 g/l. Electromyographic and nerve conduction analyses confirmed neuropathy with axonal abnormalities. Within few months appeared walking impossibility, swallowing difficulties and respiratory distress. Serum VEGF was highly elevated at 9700 pg/ml (normal range: 62–707). Steroids treatment was declined by the patient. ASCT was considered at high risk because of her poor condition (Karnofsky score of 50%), neurological defects and respiratory failure. We hypothesized that VEGF inhibition may relieve neuropathy. Bevacizumab therapy was initiated at 10 mg/kg every 2 weeks. Pain relief was observed after two infusions, followed by major improvement in walking and breathing within 10 weeks. This was correlated with a drop in VEGF level (61 pg/ml) and a significant improvement in electromyographic and nerve conduction studies. Treatment was continued for 4 months, and further clinical improvement was observed, confirmed by electroneuromyography and pulmonary function tests. Hepatomegaly and skin abnormalities remained unchanged. Karnofsky score improved at 80%, allowing ASCT conditioned with melphalan (200 mg/m) to be realized in better conditions. The procedure was well tolerated, and clinical outcome was excellent with a Karnofsky score at 90% 1 year after the procedure. Rapidly evolving neuropathy may hamper to carry out ASCT in POEMS patients. Neurological defects in our POEMS patient has been partially reversed by bevacizumab therapy, further supporting the role of VEGF in this complication. The large biological and clinical heterogeneities of POEMS syndrome could explain variable sensitivities to anti-VEGF therapy [4, 5]. Our report indicates that some patients may benefit from bevacizumab to improve their clinical condition before applying more standard treatments.

A novel anti-CD19 monoclonal antibody (GBR 401) with high killing activity against B cell malignancies

BackgroundCD19 is a B cell lineage specific surface receptor whose broad expression, from pro-B cells to early plasma cells, makes it an attractive target for the immunotherapy of B cell malignancies. In this study we present the generation of a novel humanized anti-CD19 monoclonal antibody (mAb), GBR 401, and investigate its therapeutic potential on human B cell malignancies.MethodsGBR 401 was partially defucosylated in order to enhance its cytotoxic function. We analyzed the in vitro depleting effects of GBR 401 against B cell lines and primary malignant B cells from patients in the presence or in absence of purified NK cells isolated from healthy donors. In vivo, the antibody dependent cellular cytotoxicity (ADCC) efficacy of GBR 401 was assessed in a B cell depletion model consisting of SCID mice injected with healthy human donor PBMC, and a malignant B cell depletion model where SCID mice are xenografted with both primary human B-CLL tumors and heterologous human NK cells. Furthermore, the anti-tumor activity of GBR 401 was also evaluated in a xenochimeric mouse model of human Burkitt lymphoma using mice xenografted intravenously with Raji cells. Pharmacological inhibition tests were used to characterize the mechanism of the cell death induced by GBR 401.ResultsGBR 401 exerts a potent in vitro and in vivo cytotoxic activity against primary samples from patients representing various B-cell malignancies. GBR 401 elicits a markedly higher level of ADCC on primary malignant B cells when compared to fucosylated similar mAb and to Rituximab, the current anti-CD20 mAb standard immunotherapeutic treatment for B cell malignancies, showing killing at 500 times lower concentrations. Of interest, GBR 401 also exhibits a potent direct killing effect in different malignant B cell lines that involves homotypic aggregation mediated by actin relocalization.ConclusionThese results contribute to consolidate clinical interest in developing GBR 401 for treatment of hematopoietic B cell malignancies, particularly for patients refractory to anti-CD20 mAb therapies.

A critical role of autophagy in antileukemia/lymphoma effects of APO866, an inhibitor of NAD biosynthesis

APO866, an inhibitor of NAD biosynthesis, exhibits potent antitumor properties in various malignancies. Recently, it has been shown that APO866 induces apoptosis and autophagy in human hematological cancer cells, but the role of autophagy in APO866-induced cell death remains unclear. Here, we report studies on the molecular mechanisms underlying APO866-induced cell death with emphasis on autophagy. Treatment of leukemia and lymphoma cells with APO866 induced both autophagy, as evidenced by an increase in autophagosome formation and in SQSTM1/p62 degradation, but also increased caspase activation as revealed by CASP3/caspase 3 cleavage. As an underlying mechanism, APO866-mediated autophagy was found to deplete CAT/catalase, a reactive oxygen species (ROS) scavenger, thus promoting ROS production and cell death. Inhibition of autophagy by ATG5 or ATG7 silencing prevented CAT degradation, ROS production, caspase activation, and APO866-induced cell death. Finally, supplementation with exogenous CAT also abolished APO866 cytotoxic activity. Altogether, our results indicated that autophagy is essential for APO866 cytotoxic activity on cells from hematological malignancies and also indicate an autophagy-dependent CAT degradation, a novel mechanism for APO866-mediated cell killing. Autophagy-modulating approaches could be a new way to enhance the antitumor activity of APO866 and related agents.

Anti-cancer activity of 5-O-alkyl 1,4-imino-1,4-dideoxyribitols

New derivatives of 1,4-dideoxy-1,4-imino-D-ribitol have been prepared and evaluated for their cytotoxicity on solid and haematological malignancies. 1,4-Dideoxy-5-O-[(9Z)-octadec-9-en-1-yl]-1,4-imino-D-ribitol (13, IC(50) ∼2 μM) and its C(18)-analogues (IC(50) <10 μM) are cytotoxic toward SKBR3 (breast cancer) cells. 13 also inhibits (IC(50) ∼8 μM) growth of JURKAT cells.

Nicotinic acid phosphoribosyltransferase regulates cancer cell metabolism, susceptibility to NAMPT inhibitors and DNA repair

In the last decade, substantial efforts have been made to identify NAD+ biosynthesis inhibitors, specifically against nicotinamide phosphoribosyltransferase (NAMPT), as preclinical studies indicate their potential efficacy as cancer drugs. However, the clinical activity of NAMPT inhibitors has proven limited, suggesting that alternative NAD+ production routes exploited by tumors confer resistance. Here, we show the gene encoding nicotinic acid phosphoribosyltransferase (NAPRT), a second NAD+-producing enzyme, is amplified and overexpressed in a subset of common types of cancer, including ovarian cancer, where NAPRT expression correlates with a BRCAness gene expression signature. Both NAPRT and NAMPT increased intracellular NAD+ levels. NAPRT silencing reduced energy status, protein synthesis, and cell size in ovarian and pancreatic cancer cells. NAPRT silencing sensitized cells to NAMPT inhibitors both in vitro and in vivo; similar results were obtained with the NAPRT inhibitor 2-hydroxynicotinic acid. Reducing NAPRT levels in a BRCA2-deficient cancer cell line exacerbated DNA damage in response to chemotherapeutics. In conclusion, NAPRT-dependent NAD+ biosynthesis contributes to cell metabolism and to the DNA repair process in a subset of tumors. This knowledge could be used to increase the efficacy of NAMPT inhibitors and chemotherapy. Cancer Res; 77(14); 3857-69. ©2017 AACR.

Combinative effects of β-Lapachone and APO866 on pancreatic cancer cell death through reactive oxygen species production and PARP-1 activation.

UNLABELLED Pancreatic cancer (PC) is one of the most lethal human malignancies and a major health problem. Patients diagnosed with PC and treated with conventional approaches have an overall 5-year survival rate of less than 5%. Novel strategies are needed to treat this disease. Herein, we propose a combinatorial strategy that targets two unrelated metabolic enzymes overexpressed in PC cells: NAD(P)H quinone oxidoreductase-1 (NQO1) and nicotinamide phosphoribosyl transferase (NAMPT) using β-lapachone (BL) and APO866, respectively. We show that BL tremendously enhances the antitumor activity of APO866 on various PC cell lines without affecting normal cells, in a PARP-1 dependent manner. The chemopotentiation of APO866 with BL was characterized by the following: (i) nicotinamide adenine dinucleotide (NAD) depletion; (ii) catalase (CAT) degradation; (iii) excessive H2O2 production; (iv) dramatic drop of mitochondrial membrane potential (MMP); and finally (v) autophagic-associated cell death. H2O2 production, loss of MMP and cell death (but not NAD depletion) were abrogated by exogenous supplementation with CAT or pharmacological or genetic inhibition of PARP-1. Our data demonstrates that the combination of a non-lethal dose of BL and low dose of APO866 optimizes significantly cell death on various PC lines over both compounds given separately and open new and promising combination in PC therapy.

The anti-lymphoma activity of APO866, an inhibitor of nicotinamide adenine dinucleotide biosynthesis, is potentialized when used in combination with anti-CD20 antibody.

Abstract APO866 is an inhibitor of nicotinamide adenine dinucleotide (NAD) biosynthesis that exhibits potent anti-lymphoma activity. Rituximab (RTX), an anti-CD20 antibody, kills lymphoma cells by direct apoptosis and antibody- and complement-dependent cell-mediated cytotoxicities, and has clinical efficacy in non-Hodgkin cell lymphomas. In the present study, we evaluated whether RTX could potentiate APO866-induced human B-lymphoma cell death and shed light on death-mediated mechanisms associated with this drug combination. We found that RTX significantly increases APO866-induced death in lymphoma cells from patients and lines. Mechanisms include enhancement of autophagy-mediated cell death, activation of caspase 3 and exacerbation of mitochondrial depolarization, but not increase of reactive oxygen species (ROS) production, when compared with those induced by each drug alone. In vivo, combined administration of APO866 with RTX in a laboratory model of human aggressive lymphoma significantly decreased tumor burden and prolonged survival over single-agent treatment. Our study demonstrates that the combination of RTX and APO866 optimizes B-cell lymphoma apoptosis and therapeutic efficacy over both compounds administered separately.

Hematopoietic stem cell transplantation in Switzerland: a comprehensive quality control report on centre effect

QUESTIONS UNDER STUDY / PRINCIPLES Interest groups advocate centre-specific outcome data as a useful tool for patients in choosing a hospital for their treatment and for decision-making by politicians and the insurance industry. Haematopoietic stem cell transplantation (HSCT) requires significant infrastructure and represents a cost-intensive procedure. It therefore qualifies as a prime target for such a policy. METHODS We made use of the comprehensive database of the Swiss Blood Stem Cells Transplant Group (SBST) to evaluate potential use of mortality rates. Nine institutions reported a total of 4717 HSCT - 1427 allogeneic (30.3%), 3290 autologous (69.7%) - in 3808 patients between the years 1997 and 2008. Data were analysed for survival- and transplantation-related mortality (TRM) at day 100 and at 5 years. RESULTS The data showed marked and significant differences between centres in unadjusted analyses. These differences were absent or marginal when the results were adjusted for disease, year of transplant and the EBMT risk score (a score incorporating patient age, disease stage, time interval between diagnosis and transplantation, and, for allogeneic transplants, donor type and donor-recipient gender combination) in a multivariable analysis. CONCLUSIONS These data indicate comparable quality among centres in Switzerland. They show that comparison of crude centre-specific outcome data without adjustment for the patient mix may be misleading. Mandatory data collection and systematic review of all cases within a comprehensive quality management system might, in contrast, serve as a model to ascertain the quality of other cost-intensive therapies in Switzerland.

Gray platelet syndrome: Novel mutations of the NBEAL2 gene

case that did not belong to groups (i) and (ii), ie those with equivocal results on one or both tests and those with a positive result on one test and negative result on the other. Groups (i) and (ii), collectively referred to as “concordant,” were used to determine the optimal Ct cutoff that maximized the agreement between tissue PCR results and double positivity/negativity. Biopsies were obtained from colon, duodenum, stomach, esophagus, and lung in 59 (39%), 44 (29%), 37 (24%), 7 (5%), and 4 (3%) cases, respectively. One hundred twenty-two (80%) cases were concordant (105 double-negative and 17 double-positive) and the remainder were equivocal. Viremic cases were marginally significantly more likely than nonviremic cases to be equivocal (28% vs. 14%, respectively; P5 0.055). Pathological evidence of GVHD was present in 57% vs. 52% of concordant vs. equivocal cases, respectively (P5 0.68). Similarly, these groups were not different with regards to the presence of clinical evidence of GVHD (82% vs. 90%, respectively). The optimal PCR Ct value for classification of concordant cases was 40, with good overall performance (AUC 0.91, P< 0.001), sensitivity 94%, specificity 79%, positive predictive value (PPV) 42%, and negative predictive value (NPV) 99%. Using this cutoff, 45% of equivocal cases were classified as negative. Table 1 shows the distribution of patients across H&E/IHC and PCR subgroups. Among viremic H&E/IHC-concordant cases, tissue PCR had a sensitivity of 100%, specificity of 50%, PPV of 44%, and NPV of 100%. Among non-viremic H&E/IHC-concordant cases, these numbers were 80%, 91%, 36%, and 99%, respectively. In this analysis on viremic and non-viremic cases, 31% and 62% of equivocal cases were classified as negative, respectively. One of the challenges in the diagnosis of CMV disease is H&E/IHC-equivocal cases. Avoiding potentially toxic anti-CMV treatment can be beneficial especially in nonviremic patients with negative tissue PCR. We demonstrate that a negative tissue PCR can be used to rule out CMV disease in H&E/IHC-equivocal cases. Although minimal spatial heterogeneity in the CMV target organ is assumed, we cannot rule out this possibility. Furthermore, we performed tissue PCR on FFPE specimens. The results may change if PCR were on fresh tissue, as it would be in the real-life setting. We expect the sensitivity of fresh tissue PCR to increase and specificity to decline. Until replicated in a controlled prospective study using fresh tissue samples, our results should not be used to guide treatment decisions. Our goal in this innovative, but preliminary, study was to assess the value of tissue PCR as an adjunct to H&E/IHC in the diagnosis of CMV disease, especially in equivocal cases. Future research could focus on clinical outcomes of non-viremic equivocal cases and whether anti-CMV treatment can be safely withheld in this group of patients. We could not address this question in the present work because all of our equivocal cases received anti-CMV treatment. Given the possibility of sampling error when using PCR on tissue biopsies, applying the same technique to fluid samples such as bronchioalveolar lavage or stool samples may be of value in future research.

Haematopoietic stem cell transplantation: activity in Switzerland compared with surrounding European countries

Haematopoietic stem cell transplantation (HSCT) is a highly specialised procedure used to treat malignancies of the lymphohaematopoietic system as well as some acquired and inherited disorders of the blood. This analysis by the Swiss Blood Stem Cell Transplantation Group, based on data from 2008-2011, describes, treatment rates in Switzerland for specific indications and compares this with data from Germany, France, Italy and the Netherlands, corrected for the size of the population. Differences in transplant rates, in rates for particular indications, and in the use of specific transplant technologies such as use of unrelated donors, use of cord blood or mismatched family donors are described. These data are put in correlation with donor availability from international registries and with number of transplant teams and number of procedures per team all corrected for population size.