A Rare Genetic Polymorphism In C5 Confers Poor Response To The Anti-C5 Monoclonal Antibody Eculizumab In 11 Japanese Patients With PNH

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3709-3709
Author(s):  
Jun-ichi Nishimura ◽  
Masaki Yamamoto ◽  
Shin Hayashi ◽  
Kazuma Ohyashiki ◽  
Kiyoshi Ando ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Hemolytic Activity ◽  
Research Funding ◽  
Poor Response ◽  
Heterozygous Mutation ◽  
Poor Responders ◽  
Classical Pathway ◽  
Employment Equity ◽  
Equity Ownership

Abstract Eculizumab is a humanized monoclonal antibody targeting the terminal complement protein C5 and inhibiting terminal complement-mediated hemolysis associated with paroxysmal nocturnal hemoglobinuria (PNH). In the Japanese AEGIS PNH-eculizumab study, 2 poor-responders were identified out of 29 cases. Currently, more than 300 patients have been treated with eculizumab, and a total of 11 poor-responders were identified all of whom are Japanese. To clarify the mechanism of difference in the responsiveness of eculizumab, blood samples from poor and good responders were analyzed after obtaining informed consent. Approval for these studies was obtained from the institutional review boards at each study site taking care of patients as well as from Osaka University. The levels of lactate dehydrogenase in these two patients were markedly elevated before eculizumab treatment, and were not decreased during the 12 weeks AEGIS study. From the pharmacokinetic analysis, peak and trough levels of eculizumab during the study were well above the minimal level required to completely inhibit complement-mediated hemolysis in PNH patients. The pharmacodynamics of eculizumab were determined by measuring the capacity of the patients’ serum to lyse chicken erythrocytes in a standard hemolytic assay. Serum samples analysed from these two patients failed over the entire treatment period, to show a suppression of hemolysis, prompting further study of the effect of exogenous eculizumab on the hemolytic activity of patient pre-drug sera. Eculizumab up to 2000μg/mL did not block hemolytic activity in the sera of either poor-responder. However, hemolytic activity both in the two poor-responders and in control patient was blocked completely using a different anti-C5 antibody (N19/8) at 50μg/mL. Therefore, the DNA of C5 from Japanese PNH patients with a good or poor response to eculizumab was sequenced, and a single missense C5 heterozygous mutation at exon 21, c.2654G>A, which predicts p.Arg885His, was found in all of the 11 poor responders identified to date, but not in any of the responders. Among about 300 Japanese patients treated with eculizumab, 11 patients (about 3.7%) have been identified as poor responders. A similar prevalence (3.5%) was seen in healthy volunteers, since we determined that 10 out of 288 Japanese healthy volunteers have the same mutation. This polymorphism was also identified in 1 out of 120 China Han healthy volunteers, but not in 100 persons of British ancestry living in England and Scotland, and not in 90 persons of Mexican ancestry in Los Angels. To close the genotype-phenotype loop, electrophoretically pure recombinant C5 (rC5) and rC5 mutant (rC5m) containing c.2654G>A were generated and functionally compared in various in vitro experiments. As a preliminary experiment, we confirmed that natural C5, rC5, and rC5m restored classical pathway lysis equivalently when added to C5-depleted serum. Eculizumab did not block classical pathway lysis reconstituted with rC5m but did block rC5 and nC5-dependent lysis. By contrast, as observed with patient sera, N19/8 inhibited lysis reconstituted with nC5, rC5, and rC5m. Finally, while eculizumab bound nanomolar concentrations of rC5 using surface plasmon resonance, with clear association and dissociation phases, there was no detectable binding with rC5m in the same assay up to the highest concentration (1 µM) of eculizumab examined. A single missense C5 heterozygous mutation, c.2654G>A, which predicts p.Arg885His, was commonly identified in poor-responders, but not in responders. This polymorphism had at least spread to other East Asian countries. After determining that the poor responders likely express both wild-type C5 and a structural variant C5, we then showed that the hemolytic activity supported by this structural variant in vitro, like the effects on patient sera, was not blocked by eculizumab but was fully blocked by N19/8, and that the variant was incapable of binding eculizumab. Collectively, these data are consistent with the hypothesis that the functional capacity of the mutant C5 together with its inability to bind to and undergo blockade by eculizumab fully account for the poor response in patients carrying this mutation. (JN and MY contributed equally to this work) Disclosures: Nishimura: Alexion Pharmaceuticals, Inc.: Research Funding, Speakers Bureau. Yamamoto:Alexion Pharm: Research Funding. Ohyashiki:Alexion: Research Funding. Noji:Alexion Pharmaceuticals: Honoraria. Shichishima:Alexion Pharmaceuticals: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Hase:Alexion Phama: Employment, Equity Ownership. Lan:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Johnson:Alexion Pharmaceuticals, Inc.: Employment. Tamburini:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership, Patent inventor but do not receive royalties, Patent inventor but do not receive royalties Patents & Royalties. Kinoshita:Alexion: Honoraria. Kanakura:Alexion Pharmaceuticals: Research Funding, Speakers Bureau.

The Human CD38 Monoclonal Antibody Daratumumab Improves the Anti-Myeloma Effect of Lenalidomide with Dexamethasone in Vitro

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5106-5106
Author(s):  
Michel de Weers ◽  
Michael van der Veer ◽  
Berris van Kessel ◽  
Joost M Bakker ◽  
Shulamiet Wittebol ◽  
...  
Keyword(s):  
Research Funding ◽  
Plasma Cells ◽  
Ex Vivo ◽  
Poor Responders ◽  
Employment Equity ◽  
Advisory Committees ◽  
Complement Dependent Cytotoxicity ◽  
Equity Ownership ◽  
Made In

Abstract Abstract 5106 Multiple myeloma (MM) represents an incurable malignancy of antibody-producing clonal plasma cells. Over the past decade significant progress has been made in MM treatment using novel immunomodulating agents such as lenalidomide (LEN) and bortezomib (BORT). Daratumumab (DARA) is a human CD38 antibody with broad spectrum killing activity. DARA mediates MM cell death via ADCC (antibody dependent cellular cytotoxicity), CDC (complement dependent cytotoxicity) and apoptosis. We are currently exploring the possibility to further improve MM therapy by combining novel MM therapeutics with DARA. Our initial in vitro work already showed significantly improved MM cell killing by combining DARA with LEN and BORT treatment, especially in patient samples which showed poor responses to the LEN-BORT combination. We now investigated whether DARA can also further improve therapy of lenalidomide or bortezomib in combination with corticosteroids. In ex vivo assays, which allow us to address MM cell lysis directly in BM-MNC isolated from MM patients, DARA significantly enhanced killing of MM cells that were treated with LEN or dexamethasone (DEX). Importantly, DARA was also able to enhance lysis of MM cells that were poor responders to the LEN-DEX combination. This suggests that patients might benefit from a DARA-LEN-DEX combination therapy. Experiments showing effects of DARA on killing of BORT-DEX treated cells are currently underway. The results of this study extend our previous results with LEN-BORT-DARA, showing that MM cells lysis is enhanced by DARA, especially in in samples from patients that are refractory or poorly responding to existing and novel emerging combination therapies. These results support the hypothesis that powerful and complementary effects may be achieved when DARA is combined with LEN and cortocosteroids in clinical MM studies. Disclosures: Weers: Genmab: Employment, Equity Ownership, Patents & Royalties. Veer:Genmab: Research Funding. van Kessel:Genmab: Research Funding. Bakker:Genmab: Employment, Equity Ownership. Parren:Genmab: Employment, Equity Ownership, Patents & Royalties. Lokhorst:Genmab: Membership on an entity's Board of Directors or advisory committees, Research Funding. Mutis:Genmab: Research Funding.

Coversin Blocked in Vitro Hemolysis in an Eculizumab-Resistant PNH Patient with the C5 Polymorphism (c.2654G>A)

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2138-2138 ◽  
Author(s):  
Yasutaka Ueda ◽  
Makiko Osato ◽  
Wynne Weston-Davies ◽  
Miles A Nunn ◽  
Satoru Hayashi ◽  
...  
Keyword(s):  
Research Funding ◽  
Clinical Symptoms ◽  
Poor Response ◽  
Poor Responder ◽  
Heterozygous Mutation ◽  
Intravascular Hemolysis ◽  
Advisory Committees ◽  
Hemolytic Assay ◽  
Equity Ownership

Abstract Background: Paroxysmal Nocturnal Hemoglobinurea (PNH) is a rare stem cell disease caused by the expansion of PIGA mutated clone(s). PNH-type cells are deficient in the expression of GPI-anchored proteins including DAF and CD59, which protect red blood cells (RBC) from complement-mediated intravascular hemolysis. Eculizumab (Soliris®,　Alexion Pharmaceuticals) is a humanized monoclonal antibody against C5 which efficiently inhibits hemolysis by blocking the terminal complement cascade. Eculizumab dramatically ameliorates several clinical symptoms, and improves the prognosis in PNH patients. However, among 345 Japanese PNH patients who were treated with eculizumab, 11 patients showed poor response. All the poor responders had a single missense C5 heterozygous mutation, c.2654G>A, which predicts the polymorphism p.Arg885His (Nishimura et al, NEJM. 2014 13;370(7):632-9). Two of those patients have already passed away due to severe complications related to PNH, and the rest of them are still suffered from various clinical symptoms including hemolytic episodes and RBC transfusion. In these circumstances, multiple new anti-complement drugs are under development in Japan. Coversin (Volution Immuno Pharmaceuticals) is a recombinant protein (16,740 Da) derived from a secreted protein in the saliva of the Ornithodoros moubata tick, and it blocks complement-mediated hemolysis at C5 level. In this study, we examined this new anti-complement agent to a PNH patient with C5 polymorphism c.2654G>A, as well as those without the polymorphism. Materials: Peripheral blood samples were collected from a poor responder to eculizumab and hemolytic PNH patients with written informed consent as approved by the Institutional Review Board of Osaka University Hospital. In vitro hemolytic assay: RBC from ABO-matched PNH patients off eculizumab treatment were washed 3 times in saline, and subsequently incubated with Mg2+ supplemented serum of the poor responder in the presence or absence of an anti-complement agent. Alternative pathway was activated by adding HCl (22:1 of 0.4M HCl) to the serum. Heat-inactivated (56°C for 30min) serum was used as a negative control. After a 24-hour incubation at 37°C, hemolysis was quantified by measuring the optical density at 405nm (OD405). The hemolytic activity was normalized against maximum hemolysis as induced by HCl (100%) and minimum hemolysis with inactivated acidified serum (0%). Results: A 41-year-old male with fatigue was diagnosed as aplastic anemia with PNH in 2008, and cyclosporine (CyA) was initiated at the dose of 150mg/day. The PNH clone expanded from 30.6% to 70.2% in granulocytes from 2008 to 2011 with elevated LDH (700 U/L) and the patient was referred to our hospital to undergo eculizumab treatment. CyA was reduced to 100mg/day and eculizumab was initiated in May 2012. Eculizumab treatment did not change the serum LDH level without any improvement of the symptoms: fatigue, abdominal pain, and periodical hemoglobinurea. A heterozygous mutation c.2654G>A was identified as the cause of the failure to eculizumab treatment, and he is still suffered from continuous intravascular hemolysis (LDH > 1400 U/L) with periodical acute hemolytic episodes, requiring frequent RBC transfusion. In the hemolytic assay, Coversin completely blocked hemolysis at the concentration of 10ug/ml, similar to the effective inhibition with hemolytic PNH patients without the polymorphism. Discussion: Eculizumab has dramatically improved the quality-of-life in the majority of the PNH patients by blocking intravascular hemolysis, but there are still some concerns; poor response due to C5 polymorphism, C3b deposition on the RBC, high cost and burden for scheduled infusion. Blocking the complement cascade at C5 level has shown to be relatively safe if meningococcal vaccination is properly performed, but still an extravascular hemolysis remains problematic at least in some cases. Inhibiting C3 amplification would resolve both intra and extravascular hemolysis, but susceptibility to infections remains a major concern. Our study showed that Coversin efficiently blocked in vitro hemolysis in the eculizumab resistant patient with C5 heterozygous mutation, c.2654G>A. Coversin might be a therapeutic option for the population of C5 polymorphism c.2654G>A in PNH patients. Our results warrant further investigation to explore new anti-complement agents for hemolytic PNH patients. Disclosures Ueda: Alexion Pharma: Research Funding. Osato:Alexion Pharma: Research Funding. Weston-Davies:Volution Immuno Pharmaceuticals (UK) Ltd: Employment, Equity Ownership. Nunn:Volution Immuno Pharmaceuticals: Employment, Equity Ownership. Hayashi:Alexion Pharma: Research Funding. Nishimura:Alexion Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Kanakura:Alexion Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

A Rare Genetic Polymorphism in C5 Confers Poor Response to the Anti-C5 Monoclonal Antibody Eculizumab by Nine Japanese Patients with PNH

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3197-3197
Author(s):  
Jun-ichi Nishimura ◽  
Masaki Yamamoto ◽  
Shin Hayashi ◽  
Kazuma Ohyashiki ◽  
Kiyoshi Ando ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hemolytic Activity ◽  
Japanese Population ◽  
Heterozygous Mutation ◽  
Poor Responders ◽  
Employment Equity ◽  
The Poor ◽  
Pcr Products ◽  
Equity Ownership ◽  
Terminal Complement

Abstract Abstract 3197 Paroxysmal nocturnal hemoglobinuria (PNH) is a consequence of clonal expansion of hematopoietic stem cells that have acquired a somatic mutation in PIGA. The resulting hematopoietic cells are deficient in glycosylphosphatidylinositol(GPI)-anchored proteins. Deficiency in the GPI-anchored complement regulatory proteins CD55 and CD59 accounts for the intravascular hemolysis which is the primary clinical manifestation of PNH. Eculizumab is a humanized monoclonal antibody that specifically targets the terminal complement protein C5, thereby inhibiting terminal complement-mediated hemolysis. PNH patients treated with eculizumab exhibit, significantly reduced hemolysis and thrombotic events, and improved renal impairment and QoL. Of note, in the Japanese AEGIS PNH-eculizumab study, 2 poor-responders (UPN1 and 2) were identified out of 29 cases. Currently, more than 250 patients have been treated with eculizumab, and a total of 9 poor-responders (UPN1 to 9) were identified all of whom are Japanese. To clarify the mechanism of difference in the responsiveness of eculizumab, blood samples from poor responders were analyzed. In UPN1 and 2, the levels of lactate dehydrogenase were markedly elevated before eculizumab treatment, and were not decreased during the 12 weeks AEGIS study. From the pharmacokinetic analysis, peak and trough levels of eculizumab during the study were well above the minimal level required to completely inhibit complement-mediated hemolysis in PNH patients. The pharmacodynamics of eculizumab were determined by measuring the capacity of the patients' serum to lyse chicken erythrocytes in a standard hemolytic assay. Serum samples analysed from these two patients failed over the entire treatment period, to show the typical strong inhibition of hemolysis, prompting further study of the effect of exogenous eculizumab on the hemolytic activity of patients' pre-drug serum. Eculizumab up to 2000μg/mL did not block hemolytic activity in the sera of either non-responder. However, hemolytic activity both in the two non-responders and in control patient was blocked completely using a different anti-C5 antibody (ALXN-Ab) at 50μg/mL and higher suggesting that hemolysis is C5 dependent in the sera of non-responders. Therefore, the DNA of C5 from UPN1 and 2 was sequenced, and a single missense C5 heterozygous mutation at exon 21, c.2684G>A, which predicts p.Arg885His, was found in each case. Since this one base substitution generates a new ApaLI restriction site, the PCR products covering exon 21 of C5 from the other seven poor-responders (UPN3–9) and seven responders were easily screened to verify this mutation. All PCR products from poor-responders were partially cleaved by ApaLI and confirmed as having c.2684G>A in one allele, while no mutation was found in all responders. To determine the prevalence of c.2684G>A among the Japanese population, DNA samples from Japanese healthy volunteers have been analyzed. At this moment, we estimate the prevalence around a few %, because this mutation was found in 9 out of over 250 patients with PNH (<3.6%) who received eculizumab, and in 2 out of 96 healthy volunteers (2.1%). Thus, we have observed 9 poor-responders, whose sera exhibited hemolytic activity even in the presence of high concentrations of exogenously added eculizumab. However, their hemolytic activity was completely blocked by a different anti-C5 monoclonal antibody that binds to a site on C5 other than that which is bound by eculizumab. A single missense C5 heterozygous mutation, c.2684G>A, which predicts p.Arg885His, was commonly identified in poor-responders, but not in responders. These data suggest that the poor-responders have normal levels of wild type C5 plus a functional variant that does not bind eculizumab, and that the variant is responsible for the component of hemolytic activity in the poor-responders that is refractory to eculizumab. In order to verify that the polymorphism in C5 is truly responsible for the phenomena, we have initiated studies to express recombinant C5 with the mutation and characterize its activity and function. We are also working to both determine a more reliable prevalence of this C5 polymorphism in the Japanese population and to evaluate whether it is specific to the Japanese population. Disclosures: Nishimura: Alexion Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau. Hase:Alexion Pharma G.K.: Employment, Equity Ownership. Lan:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Tamburini:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership, Patents & Royalties. Kanakura:Alexion Pharmaceuticals: Consultancy, Research Funding.

C5 Polymorphism in a Dutch Patient with Paroxysmal Nocturnal Hemoglobinuria (PNH) and No Asian Ancestry, Resistant to Eculizumab, but in Vitro Sensitive to Coversin

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1209-1209 ◽  
Author(s):  
Saskia Langemeijer ◽  
Jun-Ichi Nishimura ◽  
Wynne Weston-Davies ◽  
Miles A Nunn ◽  
Yuzuru Kanakura ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Poor Response ◽  
Healthy Controls ◽  
Employment Equity ◽  
Advisory Committees ◽  
Asian Ancestry ◽  
Equity Ownership ◽  
Terminal Complement

Abstract Eculizumab (Soliris®) is a humanized monoclonal antibody that targets complement factor C5and inhibits the production of C5a and formation of the terminal complement membrane attack complex. It is registered for the treatment of PNH and aHUS. Eculizumab results in significant reduction of hemolysis in PNH, improves symptoms and reduces the incidence of PNH related thrombosis . A poor response, defined as sustained high levels of LDH during treatment with eculizumab irrespective of improvement of clinical symptoms, has been reported in a subgroup of PNH patients (Nishimura et al, NEJM 2014;370:632-639). These patients had a genetic variant of C5 which occurs in approximately 3.5% of the Japanese and 1% of the Chinese Han populations and interferes with binding of eculizumab to C5. We describe the first patient with no known Asian ancestry with a poor response to eculizumab, who subsequently had a good in vitro response to protein rEV576 (syntheticOrnithodoros moubata complement C5 binding) or coversin. Coversin is a recombinant small protein derived from a tick salivary molecule which binds to C5 and, through steric hindrance, interferes with the access of C5 convertase to the active site and thus prevents cleavage to C5a and C5b in a similar fashion to eculizumab. Our 30-year old male patient commenced treatment with Eculizumab because of PNH (granulocyte clone size: 90%), severe haemolysis (LDH 3-6x ULN, and peak value of 17xULN), transient renal failure, extreme fatigue and erectile dysfunction. He had no history of thrombosis and no underlying bone marrow disease. During eculizumab treatment (dosed 600 mg iv every 7 days, weeks 1-4 and 900 mg biweekly starting in week 5) he felt better, seemed less fatigued and experienced less erectile dysfunction. However, laboratory examination showed sustained elevated markers of hemolysis. Other causes of hemolysis were excluded. Underdosing of eculizumab was ruled out by demonstrating sustained high LDH levels at different time points in between subsequent eculizumab infusions and by measuring trough levels of eculizumab (>100ug/ml). In vitro terminal complement complex blockage by eculizumab through antibody-coated chicken red blood cell lysis was indicative of ongoing active hemolysis in our patient's serum. The presence of Human Anti-Drug Antibodies was excluded using an illuminescent MSD®assay. Treatment was discontinued when the patient experienced increased hemolysis (LDH 9x ULN) and macroscopic hemoglobinuria one day after receiving a dose of 900 mg eculizumab. As expected, discontinuation did not result in further increase of hemolysis parameters or clinical change. To investigate whether a mutation of complement C5 might explain the eculizumab resistance in our patient, DNA analysis of the coding region of C5 was performed. This showed a single C5 heterozygous missense mutation, c.2653C>A, which predicts p.Arg885Ser. This new mutation was very similar to variants previously found in Japanese patients (c.2654G>A, which predicts p.Arg885His) and an Argentinian patient with Asian ancestry (c.2653C>T, which predicts p.Arg885Cys), indicating the importance of this amino acid in C5 recognition by eculizumab. The same mutation was demonstrated in the DNA of our patient's healthy father. Since coversin binds to an epitope on C5 remote from the eculizumab binding site, we hypothesised that it might block C5 cleavage in our patient. Serum samples from our patient and 6 healthy controls were spiked with ascending doses of either eculizumab or coversin and complement activity was measured using a commercially available CH50 Equivalent ELISA (Quidel Corporation ®). In agreement with our in vivo observation eculizumab was incapable of inhibiting CH50 activity in the patient's serum beyond approximately 75%, even at concentrations of 100ug/ml. In contrast coversin, even in concentrations of 10 ug/ml inhibited complement activity completely, both in serum of our patient and serum of healthy controls. We conclude that coversin may prove a useful alternative to eculizumab for patients with resistance due to C5 polymorphisms. Figure 1. Change in serum complement C5 activity in response to ascending doses of coversin (Cov) and eculizumab (Ecu). R2 = patient sample, NC3 = normal control Figure 1. Change in serum complement C5 activity in response to ascending doses of coversin (Cov) and eculizumab (Ecu). R2 = patient sample, NC3 = normal control Disclosures Nishimura: Alexion Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Weston-Davies:Volution Immuno Pharmaceuticals: Employment, Equity Ownership. Nunn:Volution Immuno Pharmaceuticals: Employment, Equity Ownership. Kanakura:Alexion Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mackie:Volution Immuno Pharmaceuticals (Uk) Ltd: Research Funding. Muus:Alexion Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Stroma-Free Ex Vivo Expanded, CD34+ Cord Blood-Derived NK Cells Retain Lytic Activity After Long-Term Engraftment in NSGS Mice

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 580-580
Author(s):  
Mark Wunderlich ◽  
Mahesh Shrestha ◽  
Lin Kang ◽  
Eric Law ◽  
Vladimir Jankovic ◽  
...  
Keyword(s):  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Employment Equity ◽  
Cell Product ◽  
Equity Ownership ◽  
Cellular Therapeutics

Abstract Abstract 580 Generating a large number of pure, functional immune cells that can be used in human patients has been a major challenge for NK cell-based immunotherapy. We have successfully established a cultivation method to generate human NK cells from CD34+ cells isolated from donor-matched cord blood and human placental derived stem cells, which were obtained from full-term human placenta. This cultivation method is feeder-free, based on progenitor expansion followed by NK differentiation supported by cytokines including thrombopoietin, stem cell factor, Flt3 ligand, IL-7, IL-15 and IL-2. A graded progression from CD34+ hematopoietic progenitor cells (HSC) to committed NK progenitor cells ultimately results in ∼90% CD3-CD56+ phenotype and is associated with an average 10,000-fold expansion achieved over 35 days. The resulting cells are CD16- and express low level of KIRs, indicating an immature NK cell phenotype, but show active in vitro cytotoxicity against a broad range of tumor cell line targets. The in vivo persistence, maturation and functional activity of HSC-derived NK cells was assessed in NSG mice engineered to express the human cytokines SCF, GM-CSF and IL-3 (NSGS mice). Human IL-2 or IL-15 was injected intraperitoneally three times per week to test the effect of cytokine supplementation on the in vivo transferred NK cells. The presence and detailed immunophenotype of NK cells was assessed in peripheral blood (PB), bone marrow (BM), spleen and liver samples at 7-day intervals up to 28 days post-transfer. Without cytokine supplementation, very few NK cells were detectable at any time-point. Administration of IL-2 resulted in a detectable but modest enhancement of human NK cell persistence. The effect of IL-15 supplementation was significantly greater, leading to the robust persistence of transferred NK cells in circulation, and likely specific homing and expansion in the liver of recipient mice. The discrete response to IL-15 versus IL-2, as well as the preferential accumulation in the liver have not been previously described following adoptive transfer of mature NK cells, and may be unique for the HSC-derived immature NK cell product. Following the in vivo transfer, a significant fraction of human CD56+ cells expressed CD16 and KIRs indicating full physiologic NK differentiation, which appears to be a unique potential of HSC-derived cells. Consistent with this, human CD56+ cells isolated ex vivo efficiently killed K562 targets in in vitro cytotoxicity assays. In contrast to PB, spleen and liver, BM contained a substantial portion of human cells that were CD56/CD16 double negative (DN) but positive for CD244 and CD117, indicating a residual progenitor function in the CD56- fraction of the CD34+ derived cell product. The BM engrafting population was higher in NK cultures at earlier stages of expansion, but was preserved in the day 35- cultured product. The frequency of these cells in the BM increased over time, and showed continued cycling based on in vivo BrdU labeling 28 days post-transfer, suggesting a significant progenitor potential in vivo. Interestingly, DN cells isolated from BM could be efficiently differentiated ex vivo to mature CD56+CD16+ NK cells with in vitro cytotoxic activity against K562. We speculate that under the optimal in vivo conditions these BM engrafting cells may provide a progenitor population to produce a mature NK cell pool in humans, and therefore could contribute to the therapeutic potential of the HSC-derived NK cell product. The in vivo activity of HSC-derived NK cells was further explored using a genetically engineered human AML xenograft model of minimal residual disease (MRD) and initial data indicates significant suppression of AML relapse in animals receiving NK cells following chemotherapy. Collectively, our data demonstrate the utility of humanized mice and in vivo xenograft models in characterizing the biodistribution, persistence, differentiation and functional assessment of human HSC-derived cell therapy products, and characterize the potential of HSC-derived NK cells to be developed as an effective off-the-shelf product for use in adoptive cell therapy approaches in AML. Disclosures: Wunderlich: Celgene Cellular Therapeutics: Research Funding. Shrestha:C: Research Funding. Kang:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Law:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Jankovic:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Zhang:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Herzberg:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Abbot:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Hariri:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Mulloy:Celgene Cellular Therapeutics: Research Funding.

Absence Of Mutation In Cereblon (CRBN) and DNA Damage Binding Protein 1 (DDB1) Genes In Myeloma Cells and Patients and Its Clinical Significance

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3139-3139
Author(s):  
Anjan Thakurta ◽  
Anita K Gandhi ◽  
Michelle Waldman ◽  
Chad C. Bjorklund ◽  
Suzanne Lentzsch ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Heterozygous Mutation ◽  
Employment Equity ◽  
Advisory Committees ◽  
Single Nucleotide ◽  
Truncating Mutation ◽  
Equity Ownership

Abstract Background CRBN, a target of thalidomide and IMiDs® immunomodulatory agents lenalidomide (LEN) and pomalidomide (POM), is a component of the E3 ubiquitin cullin 4 ring ligase (CRL4) complex that also includes DDB1, Roc1, and Cul4. Two CRBN mutations have been reported in multiple myeloma (MM) patients: truncating mutation (Q99) and point mutation (R283K). One copy of the CRBN gene was shown to be deleted in the MM1S and MM1S.R cell lines. No DDB1 mutation has been described previously. Results We investigated the incidence of CRBN and DDB1 mutations by next-generation sequencing in 20 MM cell lines and MM subjects. Of 90 MM patients, 24 were newly diagnosed and 66 were relapsed and refractory of which 36 patients were LEN resistant. Out of the cell lines tested, 1 heterozygous CRBN mutation (D249Y) was found in the LEN-resistant ANBL6R cells, which is located in the putative DDB1 binding domain, and 2 single silent mutations were identified in the KMS-12-BM (rs17027638) and OPM-2 cells. One DDB1 heterozygous mutation (E303D) was identified in ANBL6 cells. In the cohort of patients assessed, no CRBN mutation was detected; however, 5 single nucleotide variations (SNV) were identified. Three of the 5 SNVs were at position 735 (Y245Y) and 1 each at position 219 (H73H) and 939 (C313C), respectively. The first 2 SNVs (rs17027638 and rs1045309) are described but not the last. We found a single SNV (P51P; rs2230356) in DDB1 gene the patient samples. Conclusion Mutations within the coding sequences of CRBN and DDB1 are rare in MM patients and cell lines. Most intrinsically LEN-resistant cells and cell lines made resistant to LEN or POM do not have CRBN or DDB1 mutations, suggesting the potential role of other sources, such as genetic or epigenetic pathways in developing resistance to IMiD drug–based therapy. Disclosures: Thakurta: Celgene: Employment, Equity Ownership. Gandhi:Celgene: Employment, Equity Ownership. Waldman:Celgene: Employment, Equity Ownership. Bjorklund:Celgene: Employment, Equity Ownership. Lentzsch:Celgene: Research Funding. Schey:Celgene: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; NAPP: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Orlowski:Bristol-Myers Squibb: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Millennium: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Resverlogix: Research Funding; Array: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Merck: Membership on an entity’s Board of Directors or advisory committees. Madan:Covance Genomics Lab: Employment. Ning:Celgene: Employment, Equity Ownership. Mendy:Celgene: Employment, Equity Ownership. Lopez-Girona:Celgene: Employment, Equity Ownership. Schafer:Celgene: Employment, Equity Ownership. Avet-Loiseau:Celgene: Research Funding. Chopra:Celgene: Employment, Equity Ownership.

Phase 1 Study of CB-839, a First-in-Class, Glutaminase Inhibitor in Patients with Multiple Myeloma and Lymphoma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3059-3059 ◽  
Author(s):  
Dan T. Vogl ◽  
Anas Younes ◽  
Keith Stewart ◽  
Keith William Orford ◽  
Mark Bennett ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Research Funding ◽  
Blood Platelets ◽  
Safety Data ◽  
Employment Equity ◽  
Efficacy Data ◽  
Trough Concentrations ◽  
Equity Ownership

Abstract Background: Malignant cells alter metabolism in order to enable their highly anabolic state. In addition to a massive increase in glycolysis, malignant cells frequently become dependent on glutamine to feed the TCA cycle and provide key building blocks for cell growth and proliferation. CB-839 is a first-in-class potent and selective inhibitor of glutaminase (GLS), the first step in glutamine metabolism, that has broad in vitro and in vivo anti-tumor activity in solid and heme malignancies, including multiple myeloma. GLS inhibition with CB-839 induces apoptosis and/or growth arrest in multiple myeloma and lymphoma cell lines and is synergistic with pomalidomide and lenalidomide in vitro and as well as in multiple myeloma xenograft models in vivo. Methods: CX-839-002 is an ongoing Ph1 evaluation of escalating doses of CB-839 in patients with relapsed/refractory multiple myeloma (MM) or non-Hodgkins lymphoma (NHL) with the primary objective of assessing the safety profile and selecting a recommended Phase 2 dose (RP2D). Pharmacokinetics (PK) was monitored on Days 1 and 15. Initially, CB-839 was given three times daily (TID) without food, but based on PK and safety data generated across three Ph1 studies in patients with solid and heme malignancies, the drug is now being given twice daily (BID) with meals. Results: Safety data are available for a total of 14 patients (9 MM, 4 follicular lymphoma, 1 diffuse large B cell lymphoma) that have enrolled to date during the dose escalation (100-400 mg TID and 600 mg BID). The patients have received a median of 7 prior lines of systemic therapy. CB-839 has been well tolerated with only three subjects experiencing a Gr3/4 AEs considered possibly related to study drug and there have been no discontinuations due to AEs. A similar tolerability profile has been observed across three Ph1 studies for CB-839. With a total of 119 pts treated with CB-839 across the three studies, Gr3/4 drug-related AEs have occurred in 16 subjects (13%) and 4.3% of discontinuations were due to AEs. Reversible, asymptomatic elevations in transaminases have been the primary Gr3 AEs, occurring primarily on the TID schedule in 6/59 (10.2%) pts; only one occurred among 60 pts (1.7%) receiving the BID regimen. BID dosing with 600 mg was determined to be the RP2D and combination studies with pomalidomide and dexamethasone have been initiated. The half-life of CB-839 is ~4 hr, exposure increases with dose, and trough concentrations generally remain above the target threshold of 200 ng/mL for patients receiving the RP2D. Six of 8 MM pts that received ≥ 400 mg TID achieved steady state (D15) trough concentrations above the PK target threshold while 0 of 5 pts that received ≤ 250 mg TID achieved the PK threshold. Pharmacodynamic assessment of GLS activity in MM patients was consistent with a broader PK/PD assessment (across all 3 Ph1 studies), which established clear exposure-dependent inhibition of the target in peripheral blood platelets 4 hr after the first dose of CB-839, with >90% inhibition being maintained for most patients at the RP2D. Preliminary efficacy data include confirmed stable disease in 4 of 9 evaluable MM patients. Updated efficacy data and correlative studies on clinical samples will also be presented. The first pt treated with the combination of CB-839 and pomalidomide/dexamethasone (Pd) during dose escalation received 400 mg CB-839 BID, pomalidomide at 4 mg/day (D1-21) and dexamethasone at 40 mg on Days 1, 8, 15 and 22 of each 28-day cycle. This pt had a 71% decreased in urine M-protein and an 83% reduction in serum free light chain after the first 2 cycles of treatment. This pt had 11 prior lines of therapy but not pomalidomide and had two stem cell transplants and was progressing rapidly prior to study entry. The pt has tolerated the combination well and is continuing on study. Conclusions: CB-839 has been well tolerated at and above doses that produced robust inhibition of GLS in blood platelets and in tumors. Dosing BID with food has improved the PK profile and mitigated the frequency and severity of LFT elevations, which was the primary safety signal using TID dosing. Strong preclinical combination data, an excellent clinical safety profile, and initial data with CB-839 combined with Pd provide a strong rationale for continued development of CB-839 this combination in pts with relapsed/refractory multiple myeloma. Disclosures Vogl: Constellation Pharmaceuticals: Research Funding; Calithera Biosciences: Research Funding; Celgene Corporation: Consultancy; Acetylon Pharmaceuticals, Inc.: Research Funding; Millennium Pharmaceuticals: Research Funding; GSK: Research Funding. Younes:Celgene: Honoraria; Curis: Research Funding; Sanofi-Aventis: Honoraria; Seattle Genetics: Honoraria, Research Funding; Novartis: Research Funding; Janssen: Honoraria; Takeda Millenium: Honoraria; Bristol Meyer Squibb: Honoraria; Bayer: Honoraria; Incyte: Honoraria; Johnson and Johnson: Research Funding. Orford:Calithera Biosciences: Employment, Equity Ownership. Bennett:Calithera Biosciences: Employment, Equity Ownership. Siegel:Celgene Corporation: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Merck: Speakers Bureau. Berdeja:Curis: Research Funding; Acetylon: Research Funding; Novartis: Research Funding; Janssen: Research Funding; Takeda: Research Funding; BMS: Research Funding; Array: Research Funding; MEI: Research Funding; Abbvie: Research Funding; Celgene: Research Funding; Onyx: Research Funding.

Development of a Human Therapeutic L-Cyst(e)Ine-Degrading Enzyme for the Treatment of Hematological Malignancies

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1587-1587
Author(s):  
Giulia Agnello ◽  
Susan Alters ◽  
Joseph Tyler ◽  
Jinyun Liu ◽  
Peng Huang ◽  
...  
Keyword(s):  
Research Funding ◽  
Hematological Malignancies ◽  
Ex Vivo ◽  
Redox Balance ◽  
Lymphocytic Leukemia ◽  
Employment Equity ◽  
Equity Ownership ◽  
Antioxidant Mechanisms

Abstract Cancer cells experience higher intrinsic oxidative stress than their normal counterparts and acquire adaptive antioxidant mechanisms to maintain redox balance. This increased antioxidant capacity has been correlated to malignant transformation, metastasis and resistance to standard anticancer drugs. This enhanced antioxidant state also correlates with cancer cells being more vulnerable to additional oxidative insults, therefore disruption of adaptive antioxidant mechanisms may have significant therapeutic implications. Hematological malignancies including Chronic Lymphocytic Leukemia (CLL), Acute Lymphocytic Leukemia (ALL), Acute Myeloid Leukemia (AML) and Multiple Myeloma (MM) are critically dependent on the cellular antioxidant glutathione (GSH), consistent with the higher intrinsic oxidative stress. L-cysteine is the rate-limiting substrate for GSH biosynthesis and adequate levels of cysteine are critical to maintain the intracellular homeostasis of GSH. CLL and a subset of ALL cells have been reported to rely on the stromal supply of cysteine to increase the synthesis of GSH in order to maintain redox balance, which in turn promotes cell survival and fosters drug resistance. One approach to target this cancer specific dependency is by therapeutic depletion of amino acids via enzyme administration; a clinically validated strategy for the treatment of ALL. Aeglea BioTherapeutics Inc. has developed a bioengineered cysteine and cystine degrading enzyme (Cyst(e)inase, AEB3103) and evaluated its therapeutic efficacy against hematological malignancies in in vitro, ex vivo and in vivo pre-clinical studies. The TCL1-TG:p53 -/- mouse model exhibits a drug resistant phenotype resembling human CLL with unfavorable cytogenetic alterations and highly aggressive disease progression. AEB3103 greatly decreased the viability of TCL1-TG:p53 -/- cells cultured in vitro, whereas the CLL therapeutic, fludarabine, showed minimal cytotoxic effects. In vivo treatment of TCL1-TG:p53 -/- mice with AEB3103 resulted in an increase in median survival time (7 months, p<0.0001) compared to the untreated control group (3.5 months, p<0.001) and a fludarabine treated group (5.3 months, p<0.001). These results indicate a superior therapeutic effect of AEB3103 compared to fludarabine. Additionally, evaluation of AEB3103 in in vitro 2D cultures of patient-derived CLL and MM cells, and in ex vivo 3D cultures of cells derived from ALL and AML PDx models resulted in significant cell growth inhibition with therapeutically relevant IC50 values. Collectively these results demonstrate the sensitivity of hematological malignancies to modulation of GSH levels via AEB3103-mediated cyst(e)ine depletion. Disclosures Agnello: Aeglea BioTherapeutics: Employment. Alters:Aeglea BioTherapeutics: Employment, Equity Ownership. Tyler:Aeglea BioTherapeutics: Employment, Equity Ownership. Huang:Aeglea BioTherapeutics: Research Funding. Stone:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Research Funding; University of Texas at Austin: Employment, Patents & Royalties: I am an inventor of technology related to this abstract. Georgiou:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Lowe:Aeglea BioTherapeutics: Employment, Equity Ownership. Rowlinson:Aeglea BioTherapeutics: Employment, Equity Ownership.

scholarly journals An All Antibody Approach for Conditioning Bone Marrow for Hematopoietic Stem Cell Transplantation with Anti-cKIT and Anti-CD47 in Non-Human Primates

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4428-4428
Author(s):  
Kristopher D Marjon ◽  
James Y Chen ◽  
Jiaqi Duan ◽  
Timothy S Choi ◽  
Kavitha Sompalli ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Stem Cell ◽  
Peripheral Blood ◽  
Research Funding ◽  
Mast Cell Degranulation ◽  
Employment Equity ◽  
Cell Counts ◽  
Equity Ownership

Background Hematopoietic stem cell (HSC) transplantation (HSCT) is a well-established procedure that, with or without gene therapy, is curative for numerous severe life-threatening diseases including genetic blood disorders and blood cancers. While advances have been made, there are still substantial concerns since these chemo- and radiation therapy based procedures cause long-term toxicities such as infertility and secondary malignancies or even result in high mortality. We have previously established in a series of preclinical studies a novel chemo- and radiation-free non-toxic monoclonal antibody (Ab) -based conditioning regimen for autologous and allogeneic HSCT (Czechowicz et al., Akanksha et al. and George et al.). This cKIT-CD47 Ab-based regimen selectively depletes host HSCs for HSCT while sparing off-target toxicities caused by chemotherapy/radiation. By significantly decreasing morbidity/mortality associated with traditional conditioning regimens, antibody-mediated conditioning could expand the patient population eligible to receive HSCT for a variety of disorders. We developed a novel cKIT Ab (FSI-174), with an active Fc, and in combination with our CD47 magrolimab (previously 5F9, blocks the don't eat me pathway) could be utilized to translate the promising preclinical findings into clinical studies for safe and less toxic bone marrow conditioning for HSCT. Here we present the functional characterization of FSI-174 as single Ab and in combination with magrolimab in vitro and in non-human primate (NHP) studies. Methods We tested if FSI-174 could block stem cell factor signaling and we explored if FSI-174 alone or in combination with magrolimab could promote phagocytosis of cKIT positive cells (Kasumi-1). In addition, we determined if FSI-174 could cause mast cell degranulation. Subsequently, we explored the potential of FSI-174 alone (Phase A) or in combination with magrolimab (Phase B) to deplete HSCs in NHPs (rhesus macaques)in vivo. In Phase A, single doses of FSI-174 (0.3, 1, or 3 mg/kg) were administered alone. In Phase B, FSI-174 (0.3 or 3 mg/kg) was administered in combination with magrolimab (5mg/kg priming and 20 mg/kg maintenance dose). Bone marrow aspirates and core biopsies and peripheral blood were sampled before the study start and throughout the study. Frequency of bone marrow HSCs and cKIT receptor occupancy (RO) was determined by flow cytometry. In addition, the PK profile of FSI-174 was determined. Results In-vitro analysis demonstrated that FSI-174 decreases proliferation of HSPCs and enhances phagocytosis of cKIT positive cells, and the addition of magrolimab synergistically enhances the phagocytosis. Strikingly, FSI-174 did not cause mast cell degranulation in vitro. In the NHPs, complete (100%) cKIT receptor occupancy was achieved at all FSI-174 dose levels and was maintained for 1 to 9 days correlating with increasing doses and pharmacokinetics. The FSI-174 Cmax was found to be proportional to dose and mean Cmax increased from 6.25 ug/mL to 49.2 ug/mL. In Phase A, FSI-174 alone did not decrease the frequency of bone marrow HSCs compared to PBS control and had no effect on the peripheral blood cell counts. However, in Phase B, when FSI-174 was combined with magrolimab it significantly decreased the frequency of bone marrow HSCs with the nadir at day 9 and no recovery over 85 days compared to PBS control. Notably, there were no changes in peripheral blood cell counts over the course of the studies with no cytopenias in combination treatment. Conclusions We have developed a novel cKIT Ab (FSI-174) that meets the desired profile of stem cell factor block, promotion of phagocytosis, but without promoting mast cell degranulation. Furthermore, in the NHPs studies we have confirmed our chemo- and radiation-free cKIT-CD47 Ab -based conditioning approach with FSI-174 and magrolimab. As anticipated by our previous preclinical studies, monotherapy with FSI-174 does not deplete bone marrow HSCs in NHPs. Notably, no cytopenias are observed with either monotherapy or combination therapy. These data demonstrate the specificity, efficacy and safety of FSI-174/ magrolimab combination have great potential for conditioning regimen for HSCT in a chemotherapy and radiation free manner. Given the favorable safety profile of magrolimab across several clinical studies, these results are paving the way to the first-in-human trials for this novel conditioning for HSCT. Disclosures Marjon: Forty Seven Inc: Employment, Equity Ownership. Chen:Forty Seven Inc.: Consultancy, Equity Ownership. Duan:Forty Seven Inc.: Employment, Equity Ownership. Choi:Forty Seven inc: Employment, Equity Ownership. Sompalli:Forty Seven Inc: Employment, Equity Ownership. Feng:Forty Seven Inc: Employment, Equity Ownership. Mata:Forty Seven inc: Employment, Equity Ownership. Chen:Forty Seven Inc: Employment, Equity Ownership. Kean:HiFiBio: Consultancy; BlueBirdBio: Research Funding; Gilead: Research Funding; Regeneron: Research Funding; EMDSerono: Consultancy; FortySeven: Consultancy; Magenta: Research Funding; Bristol Meyers Squibb: Patents & Royalties, Research Funding; Kymab: Consultancy; Jazz: Research Funding. Chao:Forty Seven Inc: Employment, Equity Ownership. Chao:Forty Seven, Inc.: Employment, Equity Ownership, Patents & Royalties. Takimoto:Forty Seven, Inc.: Employment, Equity Ownership, Patents & Royalties. Agoram:Forty Seven Inc.: Employment, Equity Ownership. Majeti:FortySeven: Consultancy, Equity Ownership, Other: Board of Director; BioMarin: Consultancy. Weissman:Forty Seven Inc.: Consultancy, Equity Ownership, Patents & Royalties. Liu:Forty Seven Inc: Employment, Equity Ownership, Patents & Royalties. Volkmer:Forty Seven, Inc.: Employment, Equity Ownership, Patents & Royalties.

scholarly journals ACE910 Facilitates Its Hemostatic Effect with the Lower Concentration of Factor X Than That Required for Factor VIIa-Driven Coagulation

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1077-1077 ◽  
Author(s):  
Koji Yada ◽  
Keiji Nogami ◽  
Takehisa Kitazawa ◽  
Kunihiro Hattori ◽  
Midori Shima
Keyword(s):  
Board Of Directors ◽  
Normal Level ◽  
Research Funding ◽  
Poor Response ◽  
Employment Equity ◽  
Advisory Committees ◽  
Chugai Pharmaceutical ◽  
Hemostatic Effect ◽  
Equity Ownership ◽  
Dose Dependent

Abstract The hemostatic effect of bypassing agents such as recombinant (r) factor (F)VIIa and activated prothrombin complex concentrates (aPCC) for hemophilia A with inhibitors (HA-inh) is not always stable (Berntope, Haemophilia 2009). The mechanism(s) of its instability remain unclear, however. We have recently reported the HA-inh case showing the attenuated responsiveness to aPCC (Ogiwara, Int J Hematol. 2014). Some groups reported the hemostatic effects of the complex concentrates of FVIIa and FX (Shirahata, Haemophilia 2012) in HA-inh, suggesting that FX would play the key role in the hemostatic effect by FVIIa. ACE910, a humanized bispecific antibody to FIXa and FX mimicking the functions of FVIIIa, exerting FXase activities without FVIII(a) (Kitazawa, Nature Medicine 2012). In this study, we attempted to elucidate the dependency on FX of the FVIIa- and/or ACE910-driven coagulation. Firstly, the global hemostatic potentials in the whole blood samples obtained from the four HA-inh cases (Case 1, 2, 3 and 4) under perioperative hemostatic treatment with the intermittent administration of rFVIIa every 2-3hr were evaluated by Ca2+-triggered viscoelastometric assay with ROTEM. The first infusion of rFVIIa shortened CT (from 5,087 ± 1,261 to 1,157 ± 208 sec) and increased MCF (from 17 ± 8.7 to 58.8 ± 1.3 mm) in each case. Additional rFVIIa after the 7th administration in Case 1, the 13th in Case 2 and the 12th in Case 3 little affected CT and MCF as well as clinical symptom, indicative of poor responsiveness, while Case 4 showed the improvement of the parameters even after the frequent infusion of rFVIIa, identified as a responsive case. Thrombin generation (TG) triggered by TF (1pM) or TF (1pM) together with ellagic acid (0.3μM) was evaluated in the plasma from the cases with poor response. Peak thrombin (PeakTh) was little changed between pre- and post-additional infusion of rFVIIa in the cases with poor response, similar to the pattern of ROTEM. The level of FX antigen measured by an ELISA in the plasma was 90.5 ± 9.6 nM, showing 67% of normal control (~140 nM), of little difference among the four cases at the first administration of rFVIIa, while that in Case 1, 2 or 3 at the 7th, 13th or 12th administration, respectively, decreased to 39.1 ± 7.0 nM, equivalent to ~45% of that (86.8 ± 12.9 nM) kept in the responsive Case 4. Addition of FX (300nM) in the plasma of poor response to rFVIIa ex vivo increased PeakTh to ~80% of normal control, suggesting that FVIIa-driven hemostatic effect would be dependent upon FX. Furthermore, to investigate the FX-dependency of FVIIa- and ACE910-driven coagulation, TG in the reconstituted HA-inh model plasmas consisting of FX-deficient plasma in which FVIII was inactivated by an anti-FVIII polyclonal antibody (10BU/ml) with/without rFVIIa (50 and 150 nM) or ACE910 (10, 30 and 60 μg/ml) was evaluated in the presence of various concentrations of FX (f.c. 0 - 300 nM). The control experiment without rFVIIa or ACE910 showed the FX dose-dependent increase of PeakTh. In the plasmas with FX ranged from 50 to 300nM, PeakTh improved to almost normal level by rFVIIa as well as ACE910. Of note, with the lower concentration of FX (10-20 nM), PeakTh improved to almost normal level in the presence of ACE910, increased by 38 ± 2.4%, 45 ± 1.7% and 48 ± 0.8% compared to those in its absence, respectively, in an ACE910 dose-dependent manner, whilst the presence of rFVIIa little affected TG compared to those in its absence. Taken together, ACE910 could exert its hemostatic effect with the lower amount of FX than that required for the rFVIIa-driven coagulation. Disclosures Yada: Chugai Pharmaceutical Co., ltd: Research Funding. Nogami:Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding; Chugai: Membership on an entity's Board of Directors or advisory committees. Kitazawa:Chugai Pharmaceutical Co., Ltd: Employment, Equity Ownership, Patents & Royalties. Hattori:Chugai Pharmaceutical Co., Ltd: Employment, Equity Ownership, Patents & Royalties. Shima:Biogen: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxalta: Honoraria, Research Funding; Novo Nordisk: Honoraria, Research Funding; Kaketsuken: Honoraria.

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