Mechanism of Tissue Factor (TF) Enhancing Factor (F)VIII Activity on FXa Generation in Initial Phase of Coagulation and Interaction Between TF and FVIII C2 Domain

Abstract In the cell-based coagulation model, factor (F)VIIa complex with tissue factor (TF) initiates the blood coagulation by generating FXa as the extrinsic tenase complex and activates FIX which composes the intrinsic tenase complex. We demonstrated that FVIIa/TF directly activated FVIII in an early coagulation phase (Soeda, JTH, 2010), and TF enhanced the intrinsic tenase activity via possible interaction with FVIIIa (Ogiwara, ASH, 2010). In this study, we clarified the enhancing mechanism of intrinsic tenase activity in the TF-related up-regulation of FVIII, and identified the TF-interactive region on FVIII. To explore the enhancing mechanism of TF for FVIII regulation, we performed the FXa generation assay with various amounts of FVIII or thrombin-mediated FVIIIa, constant FIXa (1 nM), FX (300 nM) and phospholipid vesicles (PL; 20 µM) in the presence of recombinant lipidated TF (rTF, Innovin®). The Km value for FVIII in the presence of rTF was ~2.4-fold lower than that its absence (Km; 5.6±0.5, 13.3±3.7 nM, respectively, p<0.05). Similarly, the Km for FVIIIa in the presence of TF was ~1.5-fold lower than that in its absence (Km; 6.3±0.6 nM, 9.7±1.6 nM, respectively, p<0.05), supporting that the presence of TF could promote the FXa-catalyzed activation of FVIII and FVIIIa-dependent generation of intrinsic FXa. To further evaluate the effect of TF on FVIII-dependent FXa generation, the FXa generation assay with FVIIa/TF-activated FVIIIa (FVIIIa-VIIa/TF) was also performed. The initial velocity on FXa generation with FVIIIa-VIIa/TF was 22.6 nM/min. However, the initial velocity on FXa generation with FVIIIa-VIIa/TF by addition of FVIIa-inhibitor (E-76), not to generate FVIIa/TF-dependent FXa, was 3.4 nM/min, and that with FVIII alone was 0.05 nM/min. In addition, the initial velocity with FVIIa/TF alone was 10.4 nM/min. These findings supported that the TF increased FXa generation greater than the additive effect of FVIII-dependent and FVIIa/TF-dependent FXa generation in early initiation phase of coagulation prior to thrombin generation. Since tissue factor pathway inhibitor (TFPI) is present in physiological circulating whole blood, a similar experiment on FXa generation assay was repeated under the presence of TFPI, estimated to be present at 0.5 nM in the pre-coagulant state or at 15 nM in the coagulant state in circulating blood. The initial velocity on FXa generation with FVIIIa-VIIa/TF was reduced by the presence of 0.5 or 15 nM TFPI (17.9 and 12.6 nM/min, respectively). By contrast, the initial velocity on FVIIIa-VIIa/TF-dependent FXa generation with addition of FVIIa inhibitor was little reduced by 0.5 nM TFPI, whilst was reduced by 15 nM TFPI (3.5 and 2.5 nM/min, respectively). These findings supported that the TFPI possibly didn't inhibit TF on the enhanced intrinsic tenase on association with FVIII in the pre-coagulant state. We further reported that TF enabled FXa to activate FVIII, irrespective of von Willebrand factor (VWF), and the direct association of rTF and non-lipidated TF with FVIII (Furukawa, ISTH, 2015). Since TF is transmembrane protein, however, we performed a surface plasmon resonance (SPR)-based assay (BIAcore®) and solid phase-based ELISA to identify the interactive region(s) on FVIII to recombinant soluble TF (sTF; Altor BioScience), a portion of TF outside of the PL membrane. An SPR-based assay revealed the direct binding of intact FVIII, LCh (a3-A3C1C2, A3C1C2) subunit, C2 domain to immobilized sTF (Kd; 2.3±0.6, 5.8±1.0, 10.5±3.5, 11.8±0.5 nM, respectively). The intact HCh, A1 or A2 domain to sTF failed to bind, however. A non-equilibrium ELISA also revealed that sTF bound to immobilized C2 domain with moderate affinity (Kdapp; 16.9±2.2 nM), and the interaction was dependent on ionic strength and Ca2+. In addition, the presence of VWF significantly competitively inhibited the C2 and sTF binding by ~90% (IC50; 5.7 µg/ml) at the maximal concentration employed, suggesting that the C2 domain-TF interaction could activate FVIII by FXa even in the presence of VWF. We concluded that it might be possible that TF enhanced the FVIII-mediated FXa generation by not only FVIIa but also FXa, additionally this enhancing mechanism might not be suppressed by TFPI in the initiation phase of coagulation. Furthermore, TF might function to FVIII activation, irrespective of presence of VWF, by the binding to C2 domain through the competition with VWF. Disclosures Nogami: Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

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Identification of a Protein S-Interactive Site on the Factor VIII C2 Domain

Blood ◽

10.1182/blood.v128.22.3763.3763 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3763-3763

Author(s):

Furukawa Shoko ◽

Masahiro Takeyama ◽

Midori Shima ◽

Keiji Nogami

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Protein S ◽

The Other ◽

Cross Linking ◽

C2 Domain ◽

Wild Type ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Other Hand

Abstract Factor (F)VIII functions as a cofactor in the tenase complex responsible for phospholipid (PL) surface-dependent conversion of FX to FXa by FIXa. On the other hand, protein S (PS) functions as a cofactor of activated protein C that inactivates FVIII(a) and FV(a). We have reported a new regulatory mechanism on coagulation that PS directly impaired the FXase complex by competing the FIXa-FVIIIa interaction (Takeyama, Br J Haematol. 2008;143:409), and identified the PS-interactive site on the FVIII A2 domain (Takeyama, Thromb Haemost. 2009;102:645). However, the contribution of FVIII light chain (LC) to PS-binding has not been determined. In this study, several approaches were employed to assess a PS-FVIII LC interaction. The binding of FVIII LC to active site-modified FIXa (EGR-FIXa) was inhibited by PS dose-dependently (Ki; 4.6 nM) on ELISA. Because FVIII C2 domain has a binding site for FIXa, we examined whether FVIII C2 domain bound to PS. PS bound to FVIII C2 domain (Kdapp; 283 nM) by the ELISA. A SPR-based assay also revealed that FVIII C2 domain bound to PS (Kd; 62 nM). We have reported that a FIXa-interactive site exits on FVIII C2 domain (residues 2228-2240) (Soeda, J Biol Chem. 2009;284:3379). Therefore, we assessed the interaction of the synthetic peptide spanning the residues (2228-2240) with PS. ELISA showed that the peptide bound to PS (Kdapp; 104 µM). SPR-based assay also revealed that the peptide bound to PS (Kd; 31.4 µM), although scrambled peptide failed to bind to PS. Covalent cross-linking was observed between the biotynated 2228-2240 peptide and PS following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) using SDS-PAGE. This cross-linking formation was blocked by the addition of the unlabeled peptide. Furthermore, N-terminal sequence analysis of the peptide-PS product showed that one basic residue (K2239) could not be detected, supporting that this residue participates in cross-link formation. These results indicate that the 2228-2240 residues in the FVIII C2 domain, in particular K2239, may contribute to a PS-interactive site. To inquire further into the interactive region of FVIII C2 domain to PS, we prepared a stably expressed recombinant B-domainless FVIII mutants (E2228A, D2233A, K2236A, and K2239A), which were polar amino acids in the 2228-2240 residues, subsequently compared interaction with PS of the mutants with B-domainless FVIII wild type. To evaluate the binding affinity to PS, we performed SPR-based assay with the wild type FVIII and the FVIII mutants. The assay showed K2239A bound to PS with ~1.9-fold higher Kd value (28.1 nM) than that of wild type (Kd; 14.7 nM), although E2228A, D2233A, or K2236A bound to PS (Kd; 12.7, 16.3, and 10.3 nM, respectively) with no significant difference compared with wild type. In addition, to evaluate the effect of mutants for FXa generation, we assessed FXa generation assay with wild type or K2239A in the presence or absence PS, because K2239 might contribute to a PS interaction of FVIII. After each FVIII (1 nM) was reacted with various concentrations of PS in the presence of PL (20 µM) for 30 minutes, FVIII was activated by thrombin (30 nM), followed by the reaction with FIXa (40 nM) and FX (300 nM) for 1 minute. Although generated FXa with both wild type and K2239A were reduced in the presence of PS dose-dependently, compared with its absence, the inhibition ratio of K2239A was less than that of wild type (18.2% and 31%, respectively in the presence of 500 nM PS). On the other hand, the Km value on FXa generation of K2239A for various concentrations of FIXa was ~1.8-fold higher than that of wild type (5.5±0.9 and 3.1±0.2 nM, respectively), suggesting that K2239 residue, involved in the FIXa-interactive site, might contribute to the inhibition of FVIII function by PS. In conclusion, FVIII C2 domain, in particular K2239, was possible to play an important role of the inhibitory mechanism to FVIII function by PS, due to the binding to PS. Disclosures Shima: Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Nogami:Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

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The Acidic Region of Factor VIII Light Chain Contains the Thrombin-Binding Site(s) Responsible for the Cleavage at Arg1689

Blood ◽

10.1182/blood.v126.23.2270.2270 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2270-2270

Author(s):

Hiroaki Minami ◽

Keiji Nogami ◽

Midori Shima

Keyword(s):

Binding Site ◽

Board Of Directors ◽

Light Chain ◽

Research Funding ◽

Coagulation Cascade ◽

Cross Linking ◽

C2 Domain ◽

Advisory Committees ◽

Acidic Residues ◽

Dose Dependent

Abstract Thrombin-catalyzed activation of factor (F)VIII by cleavages at Arg372, Arg740, and Arg1689 is essential for the propagation phase of blood coagulation cascade. Activated FVIII (FVIIIa) forms the tenase complex and markedly amplifies the activation of FX as a cofactor of FIX. We had already demonstrated that thrombin interacts with FVIII through the residues 392-394 and 484-509 in the A2 domain and the C2 domain, and each association regulates cleavage at Arg740, Arg372, and Arg1689, respectively (Nogami K, JBC 2000, 2005; BJH 2008), and recently reported that the A1 acidic clustered region 340-350 involving the sulfated tyrosine regulate the cleavage of Arg372 (Minami et al. 55th ASH). On the other hand, Fay and colleague suggested that recombinant FVIII lacking the C2 domain retains greater than 50% cofactor activity (JBC 2010), supporting the presence of other thrombin-binding region responsible for cleavage at Arg1689 of the light chain. In this study, we attempted to identify this thrombin-binding site(s). We focused on the acidic residues 1659-1669 and 1675-1685 within the light chain, which had similar sequence to the A1 residues 340-350 in terms of involving the clustered acidic residues and sulfated tyrosine as well as hirugen residues 54-65. We prepared four of synthetic peptides corresponding to the residues 1659-1669 and 1675-1685 with sulfated tyrosine, P(1659-69s) and P(1675-85s), and with non-sulfated tyrosine, P(1659-69) and P(1675-85). The inhibitory effect on the thrombin-catalyzed FVIII activation by each peptide was evaluated in a one-stage clotting assay. Each peptide showed a dose-dependent inhibition on thrombin-catalyzed activation. These inhibitory effects were greater in order of P1675-85s, P1659-69s, P1675-85, P1659-69, and the IC50 were 25, 67, 71 and 225 µM, respectively. The peptides with sulfated tyrosine had approximately 3-fold greater inhibition of the FVIII activation by thrombin than with non-sulfated tyrosine. The IC50 in the presence of mixture of P1675-85s and P1659-69s was 30.4 µM, suggesting that these peptides had no an additive effect. The impacts of P1659-69s and P1675-85s on the thrombin-catalyzed cleavage at Arg1689 were examined by SDS-PAGE/western blotting. These peptides blocked the cleavage at Arg1689 in dose-dependent fashions. In timed-course assay, the presence of P1659-69s and P1675-85s decreased the cleavage rate of Arg1689 by 61.3 % and 81.8 %, respectively compared to its absence. The direct binding of P1659-69s and P1675-85s to thrombin was examined by surface resonance plasmon (SPR)-based assay and by the zero-length cross-linking reagent EDC. In SPR-based assay using a Biacore T200TM, thrombin bound to immobilized P1659-69s and P1675-85s directly with high affinity. The Kd values adjusted to 1:1 binding model of global fitting were 203 nM and 94 nM, respectively. EDC cross-linking in fluid-phase assay revealed that formation of EDC cross-linking products between biotinylated P1659-69s or P1675-85s and thrombin were observed in dose-dependent fashions. The products between the biotinylated peptides (800 nM) and thrombin were competitively reduced by the addition of non-biotinylated peptides. Moreover, N-terminal sequence analysis of cross-linking products between both peptides-thrombin indicated that thrombin bound to the residues 1664-1669 and 1683-1684. Taken together, we demonstrated that the A3 residues 1659-1669 (QEEIDYDDTIS) and residues 1675-1685 (EDFDIYDEDEN) contained the thrombin binding-sites responsible for proteolytic cleavage at Arg1689 of the A3 domain. Disclosures Nogami: Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Chugai: Membership on an entity's Board of Directors or advisory committees; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding. Shima:Chugai Pharmaceutical Co., Ltd. and F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Identification of a Factor X-Interactive Site on the Factor VIII A2 Domain

Blood ◽

10.1182/blood.v128.22.3760.3760 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3760-3760

Author(s):

Masahiro Takeyama ◽

Keiji Nogami ◽

Shoko Furukawa ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Binding Affinity ◽

Research Funding ◽

Cross Linking ◽

Functional Evaluation ◽

Dependent Manner ◽

Wild Type ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

A2 Domain

Abstract We have experienced a case of acquired hemophilia A with inhibitor recognizing only a factor (F) VIII A2 epitope, and reported the inhibitory mechanism for disappearing FVIII activity (Blood, 124, 4226, 2014). In summary, the patient's inhibitor IgG bound to FVIII A2N (residue 372-562) fragment and inhibited Arg372 cleavage in FVIII by FXa, suggesting that FX(a) bound to FVIII A2 domain. ELISA-based assay showed that FVIII A2 fragment bound to FX (Kd; 338 nM). We hypothesized that FVIII A2 residues 400-429 might be FX binding site according to the 3-D model of FVIII molecule, and prepared synthetic peptides (400-409, 409-419, and 420-429). The 400-409 peptide inhibited the FVIII A2-FX interaction, suggesting that the 400-409 region contributed to FX-interactive site. In this current study, we further performed the localization of a FX-interactive site on the 400-409 region in the A2 domain. A purified FXa generation assay demonstrated the 400-409 peptide decreased the generation of FXa in a dose-dependent manner up to 38% of 100 μM (Ki; 23 ± 9 nM). In comparison, scrambled peptide of 400-409 decreased up to 10% of 100 μM. These data demonstrated that the 400-409 peptide inhibited the generated FXa, suggesting the 400-409 region contributed to regulate the coagulation function. Covalent cross-linking was observed between the biotinylated 400-409 peptide and FX following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. This cross-linking formation was blocked by the addition of unlabeled 400-409 peptide. N-terminal sequence analysis of the peptide-FX product demonstrated that two sequential residues (Lys408 and Ser409) could not be detected, supporting that two residues participate in cross-link formation. To confirm the significance of these residues in A2 domain for FX-binding, the mutant forms of the A2 domain, converted to alanine, were expressed in BHK system and purified. Compared with wild type FVIII (Kd; 10 ± 3 nM), the binding affinity of Ser409Ala FVIII mutant for FX was no significant difference (Kd; 14 ± 1 nM) on SPR-based assay. Lys408Ala or Lys408Ala/Ser409Ala double FVIII mutant, however, decreased the binding affinity by 3.6~4.3-fold (Kd; 36 ± 7 or 43 ± 2 nM, respectively), suggesting contribution of Lys408Ala to the binding interaction. For the functional evaluation of the association with FVIII mutants to FX, a FXa generation assay was repeated. Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant reacted with varying concentrations of FX decreased by 1.2~1.6-fold (Km; 53 ± 12, 69 ± 15, or 65 ± 15 nM, respectively) compared to wild type FVIII (Km; 43 ± 9 nM), supporting a contribution of these mutants to Km and overall catalytic efficiency. Vmax values were largely unaffected by the mutations with most values within approximately 30% of the wild-type value. On the other hand, Kcat/Km value of Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant were decreased by 0.5~0.7-fold (Kcat/Km; 1.0, 1.3, or 0.9 nM-1min-1, respectively) compared to wild type FVIII (Kcat/Km; 1.8 nM-1min-1), suggesting low catalytic efficacy of Lys408Ala and Ser409Ala. These results indicate that the 400-409 region in the FVIII A2 domain, and in particular Lys408 and Ser409, may contribute to a unique FX-interactive site. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

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

Blood ◽

10.1182/blood.v126.23.1077.1077 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1077-1077 ◽

Cited By ~ 1

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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Shift to Anti-Fibrinolysis on the Administration of L-Asparaginase (L-Asp) during Induction Therapy for Pediatric Acute Lymphoblastic Leukemia (ALL)

Blood ◽

10.1182/blood.v128.22.5156.5156 ◽

2016 ◽

Vol 128 (22) ◽

pp. 5156-5156

Author(s):

Takashi Ishihara ◽

Keiji Nogami ◽

Tomoko Matsumoto ◽

Yasufumi Takeshita ◽

Akitaka Nomura ◽

...

Keyword(s):

Board Of Directors ◽

Induction Therapy ◽

Research Funding ◽

The Other ◽

Induction Phase ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Hepatic Synthesis ◽

Coagulation And Fibrinolysis

Abstract Introduction: Thromboembolism is a serious complication associated with ALL. The use of central venous catheter and treatment protocols involving corticosteroids and L-Asp is assumed as important thrombogenic factors at the induction phase. In particular, L-Asp has profound effects on hepatic synthesis of pro-, anti-coagulant and fibrinolytic factors. In this study, we hypothesized that change of coagulation and fibrinolytic function contributes to hyper-coagulation condition during the induction phase with L-Asp. In order to clarify this, we evaluated the dynamic change in coagulation and fibrinolysis by simultaneous measurement of both thrombin and plasmin generation assay (T/P-GA). Patients: Twenty-seven pediatric patients with newly diagnosed ALL were enrolled from Aug. 2014 to Oct. 2015 at 3 hospitals in Japan. All cases had no thrombotic predisposition. Eighteen cases (66.7%) (BCP-ALL; n=17, T-ALL; n=1) received Berlin-Frankfürt-Münster (BFM)-95 oriented induction therapy included prednisolone (and dexamethasone for T-ALL), vincristine, daunorubicin, and E.coli L-Asp (a total of 8 doses of 5,000 U/m2). The others (BCP-ALL; n=8, T-ALL; n=1) received Japan Association of childhood Leukemia Study (JACLS) ALL02 oriented induction therapy included prednisolone, dexamethasone, vincristine, daunorubicin, cyclophosphamide and E.coli L-Asp (a total of 6 doses of 6,000 U/m2). Methods: The individual hemostatic parameters were monitored by fibrinogen (Fbg), FDP, AT, TAT and PIC. Additionally, the global functions of coagulation and fibrinolysis were evaluated using T/P-GA established by our group [Matsumoto et al. TH 2013]. This assay was initiated by the addition of a mixture of optimized concentrations of tissue factor and tissue-type plasminogen activator. Thrombin and plasmin generation were monitored simultaneously using individual fluorescent substrates in separate microtiter wells. Standard curves were set using purified alpha-thrombin and plasmin. Patients' plasmas were collected at the following points, T0; pre-phase of L-Asp, T1; intermittent phase of L-Asp, T2; post-phase of L-Asp, and T3; post-induction phase. Endogenous potentials of thrombin generation (T-EP) for coagulant activity and plasmin peak levels (P-Peak) of plasmin generation for fibrinolytic activity were selected as parameters for evaluation in this study. A ratio of T-EP and P-Peak of patients' plasmas to those of control normal plasma were calculated. Results: All cases obtained first remission, and none of them developed coagulopathy. Six cases received FFP transfusion for low Fbg level, whilst 21 cases received AT supplement for low AT level. Fbg showed a median of 170, 99.0, 99.0 and 328 mg/dl at T0, T1, T2 and T3, respectively, whilst the other individual parameters showed relatively unchanged. T-EP revealed a median of 1,126, 1,059, 1,175, 1,343 and 1,132 nM, whilst P-Peak showed a median of 6.67, 4.54, 4.12, 5.50 and 5.77 nM for T0, T1, T2, T3 and control plasma, respectively, indicating the elevated T-EP ratios and reduced P-Peak ratios (Fig. 1). The most significant difference in both ratios demonstrated a median of 1.5-fold (range, 1.0 to 2.6) at T2, consistent with the lowest Fbg levels. The FFP transfusion group showed significantly lower T-EP ratios than non-transfusion group at T1 (a median of 0.87 vs. 1.01, P=0.041) and T2 (a median of 0.96 vs. 1.07, P=0.009), whilst P-Peak ratios revealed no significant changes. The AT supplement group showed no significant changes of both ratios. Conclusion: The results from decreased Fbg and unchanged FDP might reveal the hepatic synthesis disorder of Fbg, whilst the results from T/P-GA showed that their hemostatic dynamics appear likely to be thrombotic tendency, since their coagulation state was hyper-coagulation and anti-fibrinolysis at post-phase of L-Asp. These results suggest that the impaired balance of coagulation and fibrinolysis due to L-Asp therapy might play an important role of a thrombotic complication at induction phase. On the other hand both conventional FFP transfusion and AT supplement therapy might not dramatically repair this unbalance state. A further research would be required to examine the role of coagulant and fibrinolytic function using T/P-GA in the pathogenesis of coagulopathy associated with L-Asp therapy in order to establish the optimal supportive therapy. Figure 1 The Changes of Both T-EP and P-Peak Ratios Figure 1. The Changes of Both T-EP and P-Peak Ratios Disclosures Nogami: F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Matsumoto:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Patents & Royalties, Research Funding. Shima:Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding.

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Outcome of the Japanese Immune Tolerance Induction (ITI) Registry and Predictors of Successful ITI

Blood ◽

10.1182/blood.v126.23.3526.3526 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3526-3526 ◽

Cited By ~ 1

Author(s):

Keiji Nogami ◽

Masashi Taki ◽

Tadashi Matsushita ◽

Shouichi Ohga ◽

Hideji Hanabusa ◽

...

Keyword(s):

Success Rate ◽

Board Of Directors ◽

Research Funding ◽

Retrospective Cohort ◽

Tolerance Induction ◽

Successful Outcome ◽

Advisory Committees ◽

Immune Tolerance Induction ◽

Chugai Pharmaceutical ◽

Severe Type

Abstract [Background] Immune tolerance induction (ITI) therapy is the only therapeutic approach that can eradicate factor (F)VIII and FIX inhibitors in patients with hemophilia A (HA) and B (HB), respectively. Although results of several retrospective cohort studies have been published, predictors of successful outcome are still debated. Nonetheless, little information is so far available in terms of large ITI cohort in non-Caucasian countries. [Aim] In this study, we performed a retrospective cohort study on ITI therapy carried out for Japanese hemophilia patients with inhibitors to understand the status of practice on this therapy in Japan and to study the predictors of successful outcome. [Methods] As of March 31, 2015, the registry of ITI therapy in Japanese hemophilia patients had received reports on 155 HA patients (140 severe type, high responder 69.1%) and 7 HB patients (7 severe type, high responder 42.5%) who have undergone this therapy from 45 hospitals including Hemophilia Treatment Centers since 2000. The ITI outcome was centrally reviewed. The success of ITI was defined as an undetectable inhibitor for 2 successive measurements, and the salvage ITI was defined as any rescue ITI regimen by using von Willebrand factor-containing FVIII concentrates. [Results] Among the completed ITI courses, the overall success rate of ITI therapy was 71.2% (94/132) and 83.3% (5/6) for HA and HB patients, respectively. Cumulated ITI success rates of 50% and 80% for HA patients were achieved at 1.6 and 4.3 years after the inhibitor diagnosis, and 0.6 and 2.3 years after the initiation of ITI, respectively. Significant predictors for success of ITI in HA were (i) low responding inhibitors (success 35/37 (94.5%)) compared to high responding inhibitors (59/93 (63.4%); p <0.0001), (ii) shorter intervals from inhibitor diagnosis to the initiation of ITI (success (S): 1.85±3.52 vs failure (F): 3.38±3.77 years; p =0.02), (iii) lower historical peak titers on pre-ITI (S: 24.9±55.2 vs F: 132±295 BU/ml; p =0.04), and (iv) lower peak inhibitor titers on-ITI (S: 72.4±231 vs F: 916±1,307 BU/ml; p <0.01). However, outcome was not significantly different (p =0.77) between high dose regimens (>90 IU/kg, 7 days/wk) and low dose regimens (<75 IU/kg, 3 days/wk). Also, either FVIII products (plasma-derived or recombinant) at the initiation or the insertion of central venous access devise (CVAD) did not affect the outcome (p =0.32 and 0.85). Although the outcome prediction was difficult for HB because of low number of the cases registered, success rate was much higher than those of previous reports. The success rate of salvage ITI was 50% (6/12) for HA. The significant predictive parameter for outcome was only the age at the initiation of salvage ITI (p =0.03). The inhibitor relapsed in 6 cases, and all cases were HA patients (4.5% 6/140). In 86 cases with insertion of CVAD, the catheter-related infection was complicated in 21 cases (12.9%). [Conclusion] This study underscores the importance of initiating the ITI as early as possible after the diagnosis of inhibitor and the low response of inhibitor titer before and during the ITI to maximize the success of the treatment for Japanese hemophilia patients. Disclosures Nogami: Chugai: Membership on an entity's Board of Directors or advisory committees; Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding. Taki:Biogen, Baxalta, Bayer, Novo, Pfizer: Honoraria; Biogen, Baxalta, NovoNordisk, CSL-Behring, Kaketsuken, Chugai: Research Funding. Matsushita:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Biogen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; CLS-Behling: Research Funding; Japan Blood Products Organization: Honoraria, Research Funding; Kyowa-Kirin: Honoraria, Research Funding; Octapharma AG: Honoraria; Sysmex: Speakers Bureau; Seamens: Speakers Bureau; Nihon Pharmaceutical: Honoraria, Research Funding, Speakers Bureau; Kaketsuken: Honoraria, Research Funding, Speakers Bureau; Asahi Kasei Pharma: Honoraria, Research Funding, Speakers Bureau; Eisai: Research Funding; Novartis Pharma: Honoraria, Speakers Bureau; Bayer Healthcare: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novo Nordisk Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai Pharmaceutical Co., Ltd.: Research Funding. Hanabusa:Novo Nordisk, Baxalta, Bayer, Pfizer, Biogen, and KaketsuKen: Honoraria; Novo Nordisk, Baxalta, KaketsuKen, and Biogen: Membership on an entity's Board of Directors or advisory committees. Shima:Pfizer: Honoraria, Research Funding; Kaketsuken: Honoraria; Biogen: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; Baxalta: Honoraria, Research Funding.

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Blocking Protein S Improves Hemostasis in Hemophilia a and B

Blood ◽

10.1182/blood.v128.22.79.79 ◽

2016 ◽

Vol 128 (22) ◽

pp. 79-79

Author(s):

Luca Bologna ◽

Raja Prince ◽

Mirko Manetti ◽

Daniela Melchiorre ◽

Irene Rosa ◽

...

Keyword(s):

Blood Loss ◽

Board Of Directors ◽

Tissue Factor ◽

Research Funding ◽

Hemophilia A ◽

Protein S ◽

Advisory Committees ◽

Intense Staining ◽

Preliminary Results

Abstract Introduction&Aim Hemophilia A and B are X-linked disorders caused by an absence or a reduction in coagulation FVIII and respectively, FIX. Patients with hemophilia often suffer from spontaneous bleeding within the musculoskeletal system, such as hemarthrosis. Here, we investigated whether targeting protein S (PS) could promote hemostasis in hemophilia by re-balancing coagulation. PS is a natural anticoagulant, acting as non-enzymatic cofactor for activated protein C (APC) in the inactivation of FVa and FVIIIa, and for tissue factor pathway inhibitor (TFPI) in the inhibition of FXa. This dual role makes PS a key regulator of the inhibition of thrombin generation (TG). Methods & Results Hemophilic (F8-/- or F9-/-) Pros1+/- mice were intercrossed. F8-/-Pros1-/- and F9-/- Pros1-/- mice were viable and found at the expected Mendelian frequency with no increased mortality compared to hemophilic mice. F8-/-Pros1-/- mice did not show DIC onset neither an increased mortality once challenge with tissue factor (TF). Ex vivo evaluation of TG potential showed that F8-/-Pros1-/- mice were APC-resistant, they had an improved low TF induced-TG and a 20% more dense fibrin network with larger fibrin fibers diameter as compared to F8-/-mice. Comparable results were found in human HA plasma where blocking PS raised TG even in the presence of high inhibitor titer. To assess the in vivo effect of PS inhibition on HA mice hemostasis, two tail- clipping (TC) assays were used. In both, mild TC model (2 mm cut) and severe TC (4 mm cut), blood loss significantly decreased in F8-/-Pros1-/- compared to F8- /- mice (mild TC: 407±21 vs 661±29ul, p<0.0001; severe TC:173±14 vs 249±24ul, p<0.05). In addition, the infusion of anti-hPS antibody on F8-/-Pros1+/- mice, reduced the blood loss compared to F8-/-Pros1+/- mice infused with an isotype IgG (196±10 vs 302±25ul, p=0.005). As recurrent joint bleeding is the most common manifestation of HA, we challenged F8-/-Pros1-/- mice in an acute hemarthrosis (AH) model. Joint swelling 72 hours after injury was reduced in F8-/-Pros1-/- compared to F8-/- (0.11±0.03 vs 1.02±0.07mm, p<0.0001, n=10). These results were also confirmed by s.c. injection of anti-hPS antibody (0.46±0.0 vs 0.78±0.09mm isotype IgG, p=0.02, n=9) and by i.v. injection of PS-siRNA prior to AH challenge in F8-/-Pros1+/- (0.29±0.09 vs 0.92±0.12mm siRNA control, p=0.03, n=5) and F8-/- mice(0.35±0.08 vs 0.78±0.09mm siRNA control, p=0.05, n=5). Similar results were obtained in F9-/-Pros1-/- mice. Histological analysis of joint showed joint bleeding reduction in F8-/-Pros1-/- compared to F8-/- and an increased fibrin staining comparable to F8+/+ mice.To understand the intra-articular hemostatic effect of blocking PS, joint sections were stained for TFPI. Preliminary results indicate a massive staining in the synovia of F8-/- mice, while F8-/-Pros1-/- and F8+/+ mice present a less intense signal. These data suggest that the intra-articular space is a modulable anticoagulant environment. Human HA joint tissues were then analyzed for both PS and TFPI. A strong signal was found for TFPI and PS in the synovial lining and sublining layers of HA patients on demand (n=7). Interestingly, PS and TFPI stainings were remarkably decreased in HA patients under prophylaxis (n=5). Joint section from osteoarthritis patients (n=7) did not show an intense staining for TFPI and PS similarly to hemophilic patients under prophylaxis. To understand the improved phenotype of F8-/-Pros1-/- after AH, the function of macrophages were investigated. At the steady state, F8-/-Pros1-/- presented significantly 2-fold increased levels of inflammatory macrophages (M1) than in F8-/- mice. In addition bone marrow derived macrophages from F8-/-Pros1-/- exhibit 10-fold higher RBC phagocytic activity than F8-/- . Preliminary results indicate an increase of a monocyte attractant MCP-1 level, in knee lavage after AH in F8-/-Pros1-/- than F8-/- mice. Conclusion These data provide the first evidence that blocking PS has the ability to ameliorate hemophilia as judged by in vivo improvement of bleeding phenotype in the TC assay as well as in the AH model, suggesting a new valuable tool for hemophilia therapy. In addition, the modulable presence of PS and TFPI in human and mice joints is a novel pathophysiological aspect of hemarthrosis and constitutes a potential therapeutical target. Disclosures Kremer Hovinga: NovoNordisk: Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL-Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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A New Classification of Mild/Moderate Hemophilia Α Based on a Multi-Dimensional FVIII(a) Functions Evaluated By a Plasma-Based Factor Xa Generation

Blood ◽

10.1182/blood.v128.22.1392.1392 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1392-1392

Author(s):

Koji Yada ◽

Keiji Nogami ◽

Arisa Takenaka ◽

Takeshi Kawamura ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Matched Control ◽

Factor Xa ◽

Binding Region ◽

Advisory Committees ◽

Simple Method ◽

Chugai Pharmaceutical ◽

Thrombin Cleavage ◽

Group B

Abstract In mild/moderate hemophilia A (MHA), the real hemostatic potential of their innate factor (F) VIII(a) may not be evaluated by FVIII activity (FVIII:C) obtained in a one-stage clotting assay. We often experience the discrepancies between clinical phenotype and FVIII:C in MHA patients. In order to elucidate the hemostatic potentials of the innate FVIII in MHA patients with a simple method, we here have established a plasma-based FXa generation assay (PB-XaG) to clarify the multi-dimensional functions of FVIII(a) in MHA determined by the interaction with the components of tenase complex consisting of FIXa, FX, and phospholipid (PL). XaG was evaluated in the patients' plasmas and in the control plasma dilutions consisting of FVIII-deficient plasma and serial dilutions of recombinant FVIII (1-100 IU/dL) by a chromogenic substrate S-2765 together with human plasma-derived (pd)FIXa (0-20 nM), pdFX (0-200 nM), and PL vesicles (0-114 µM) initiated by thrombin (0.01 nM). The interaction between FVIIIa and each component of tenase complex was evaluated by Michaelis-Menten's kinetic parameters, Vmax and apparent Km (Kmapp). We investigated the PB-XaG in the plasmas obtained from 17 MHA patients, carrying F8 mutations and FVIII:C as shown in the table. The PB-XaG showed that the group A, consisting of the case 1, 2, 3 and 4 with mutations at the residue(s) essential to formation of the inter-domain surface in the FVIII molecule, possessed ~1.8-7.1-fold increases in Kmapp for FIXa (10±0.9, 49±17, 31±6 and 9±3 nM, respectively) compared to FVIII:C-matched control (6.5±1.3 nM), whilst Kmapp for FX and PL in this group were of little difference from that in control, indicative of the reduced affinity for FIXa. The group B, including the case 5, 6, 7, 8 with mutations at the A2 or A3 domain remote from the PL-binding region on the C2 domain (residue 2303-2332) and the case 9 with the mutation at the PL-binding region, demonstrated ~1.7-4.8-fold increases in Kmapp for PL (4.3±2.4, 5.0±1.0, 6.5±1.3, 12±4.0 and 3.0±0.6 µM, respectively) compared to control (2.0±0.4 µM), whilst Kmapp for FIXa and FX in this group were similar to that in control, indicative of the reduced affinity to PL. Noteworthy, the apparent catalytic efficiencies defined as Vmax/Kmapp were 0.033 min-1 for the case 6 and 0.019 min-1 for the case 8 with mutations at the A3 domain, 0.3 or 0.1-fold lower than that for the case 9 (0.19 min-1) with mutation at the PL-binding region. The PB-XaG showed that the group C consisting of the case 10, 11, 12, 13, 14 and 15 demonstrated ~1.6-7.5-fold increases in Kmapp for FX (22±9, 23±9, 24±9, 10±4, 4.6±1.6 and 5.8±3.0 nM, respectively) compared to control (4.5±0.8 nM), whilst Kmapp for FIXa and PL in this group were similar to that in control, indicative of the reduced affinity to FX. Interestingly, the case 16 classified in the group C' showed enhancing affinity with FX represented by a half decrease of Kmapp for FX compared to FVIII:C-matched control (2.0±0.9 and 4.8±1.5 nM, respectively). By contrast, the case 17 with mutation at the thrombin cleavage site categorized in the group D demonstrated any little XaG initiated by thrombin for all axes of FIXa, FX and PL. Taken together, the function of FVIII(a) in MHA could be evaluated multi-dimensionally and clearly classified into the some types of interaction with FIXa, FX, PL and thrombin by the PB-XaG. Our plasma-based XaG assay would be a useful tool for functional analyses of FVIII(a) to clarify the mechanism(s) of hemostatic heterogeneity in mild/moderate HA. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding. Shima:F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

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Quality of Life and Karnofsky Performance Status in Patients with Relapse or Refractory Primary Central Nervous System Lymphoma during Phase I/II Study of Tirabrutinib

Blood ◽

10.1182/blood-2021-146439 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4561-4561

Author(s):

Yasuhito Terui ◽

Yoshitaka Narita ◽

Motoo Nagane ◽

Kazuhiko Mishima ◽

Yoshiki Arakawa ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Karnofsky Performance Status ◽

Performance Status ◽

Central Nervous System Lymphoma ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Eortc Qlq C30 ◽

Eortc Qlq

Abstract Background: Based on the results of a phase I/II study in Japan (Trial registration: JapicCTI-173646), tirabrutinib (TIR), a second-generation inhibitor of Bruton's tyrosine kinase, was approved in March 2020 for the treatment of relapsed or refractory primary central nervous system lymphoma (r/r PCNSL). We have previously reported overall response rate of 63.6% and manageable safety profile results of this study (Narita et al. Neuro Oncol. 2021;23(1):122-133). Further, one-year follow-up data after the last patient had enrolled showed that the effects of TIR persisted in r/r PCNSL patients (Mishima et al. Poster presented at the Society for Neuro-Oncology virtual conference; November 19-21, 2020). Here, based on this one-year follow-up data, we describe the Quality of Life (QoL) and Karnofsky Performance Status (KPS) in r/r PCNSL patients treated with TIR. Methods: Patients with r/r PCNSL, age ≥20 years, and KPS ≥70 were treated with TIR once daily (QD) at a dose of 320 mg, 480 mg, or 480 mg upon fasting (480 mg fasted QD). TIR was administered in 28-day cycles, and treatment was continued until disease progression or clinically unacceptable toxicity was observed. QoL was assessed using questionnaires issued by the European Organization for Research and Treatment of Cancer (EORTC), namely QLQ-C30 (EORTC QLQ-C30), EORTC QLQ-BN20, and EuroQol 5 dimensions 3-level (EQ-5D-3L). The QoL survey was conducted during the screening period, on Day 28 of Cycle 1, after every 2 cycles (i.e., after Day 1 of Cycle 3), after every 4 cycles (i.e., after Day 1 of Cycle 25), and at the end of treatment. KPS was measured during the screening period, on days 1, 8, 15, and 28 of Cycle 1, on day 1 of every cycle after Cycle 3, and at the end of treatment. Results: Forty-four patients were prospectively enrolled, and 20, 7, and 17 patients were treated with TIR at 320 mg QD, 480 mg QD, and 480 mg fasted QD, respectively. Median patient age was 60 years (range 29-86). Median follow-up period was 14.9 months (range, 1.4-27.7) for the entire cohort but was 19.1 months, 23.5 months, and 12.0 months for the 320 mg QD, 480 mg QD, and 480 mg fasted QD groups, respectively. At the time of data cutoff (February 25, 2020), 11 patients (25%) remained on treatment. Mean (SD) score for the global health status/QoL section of the EORTC QLQ-C30 was 50.9 (23.7) at baseline and remained relatively constant during treatment (Figure 1). This trend was also observed for emotional function, cognitive function, and fatigue sections of the EORTC QLQ-C30, for motor dysfunction, communication deficit, weakness of legs, and bladder control sections of the EORTC QLQ-BN20, and in items pertaining to self-care, usual activities, and anxiety/depression in the EQ-5D-3L. Median KPS was 80.0 (range, 70-100) at baseline, which remained unchanged during TIR treatment (Figure 2). Conclusion: QoL and KPS scores in r/r PCNSL patients were maintained during TIR administration, a new treatment option for r/r PCNSL, which does not lead to the deterioration of QoL and KPS. Figure 1 Figure 1. Disclosures Terui: Ono Pharmaceutical: Speakers Bureau; MSD: Speakers Bureau; Janssen: Speakers Bureau; Esai: Speakers Bureau; Chugai Pharmaceutical: Speakers Bureau; Celgene: Speakers Bureau; AbbVie: Speakers Bureau; Takeda Pharmaceutical: Speakers Bureau. Narita: Ono Pharmaceutical co.: Honoraria, Research Funding; Dainippon-Sumitomo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Honoraria, Research Funding; Stella-pharma: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Bayer: Research Funding; Ohara: Research Funding; Chugai Pharmaceutical co.: Honoraria; Novocure: Honoraria. Nagane: AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Honoraria, Research Funding; Pfizer: Research Funding; MSD: Research Funding; Astellas: Research Funding; Nippon-Kayaku: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; Shionogi: Research Funding; Otsuka: Research Funding; Ono Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novocure: Honoraria; Sumitomo Dainippon Pharma: Honoraria; RIEMSER: Membership on an entity's Board of Directors or advisory committees. Mishima: Ono Pharmaceutical Co: Research Funding; Astellas: Research Funding; HOYA Technosurgical Co.: Research Funding; Daiichi-Sankyo: Research Funding; AbbVie: Research Funding; Medical U and A: Research Funding; Teijin Pharma: Research Funding; Eisai: Research Funding; MSD: Research Funding; Chugai: Research Funding. Arakawa: Sanofi: Research Funding; Carl Zeiss: Honoraria, Research Funding; Brainlab: Honoraria, Research Funding; Nihon Medi-Physics: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Philips: Research Funding; Siemens: Research Funding; Tanabe Mitsubishi: Research Funding; Chugai: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Meiji Seika: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Takeda: Research Funding; Pfizer: Research Funding; Stryker: Research Funding; Astellas Pharma: Research Funding; Taiho Pharma: Research Funding; Nippon Kayaku: Honoraria; Novocure: Honoraria; UCB Japan: Honoraria; Integra Japan: Honoraria; Otsuka: Honoraria; Abbvie: Honoraria. Yonezawa: Eisai: Speakers Bureau; Ono Pharmaceutical co.: Speakers Bureau; Chugai Pharmaceutical co.: Speakers Bureau. Fukuhara: Celgene: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria; HUYA Bioscience International: Honoraria; Incyte: Research Funding; Janssen: Honoraria; Kyowa Kirin: Honoraria; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria; Zenyaku Kogyo: Honoraria; Bayer: Research Funding; AbbVie: Honoraria. Sugiyama: Daichi Sankyo Inc.: Consultancy; Ono Pharmaceutical Inc: Honoraria. Aoi: Ono Pharma USA, Inc.: Current Employment. Nishikawa: Novocure: Consultancy; Chugai: Honoraria, Research Funding; MSD: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Ono: Honoraria; Nihon-Kayaku: Honoraria. OffLabel Disclosure: Tirabrutinib. Clinical trial for PCNSL.

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Factor XI Activation In Tissue Factor-Initiated Blood Coagulation

Blood ◽

10.1182/blood.v118.21.2239.2239 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2239-2239 ◽

Cited By ~ 1

Author(s):

Thomas Orfeo ◽

Matthew Gissel ◽

Matthew Whelihan ◽

Saulius Butenas ◽

Kenneth G. Mann

Keyword(s):

Computational Model ◽

Board Of Directors ◽

Tissue Factor ◽

Active Site ◽

Thrombin Generation ◽

Zymogen Activation ◽

Advisory Committees ◽

Initiation Phase ◽

Contact Pathway ◽

Feedback Activation

Abstract Abstract 2239 Introduction. In in vitro models of tissue factor (TF)-initiated coagulation, FXI activation has been linked to increased thrombin generation. However the effects of FXI in experimental models of normal hemostasis have often been subtle, prompting ongoing investigations to define contributing cofactors, potential collaborating activators and/or reaction conditions (e.g. low TF concentrations). In this study, predictions from a computational model of TF-initiated thrombin generation that includes thrombin dependent FXI activation are used to direct an investigation of the role of FXI in two empirical models of TF-initiated coagulation. Methods. FXI activation and FXIa interactions were computationally modeled by adding the appropriate sets of equations describing thrombin activation of FXI, FXIa activation of FIX, antithrombin inhibition of FXIa, and high molecular weight kininogen binding to FXI to the existing framework of differential equations. The efficacy of FXIa in promoting thrombin generation (α- thrombin-antithrombin, αTAT) was assessed via titration in contact pathway inhibited whole blood and compared to activation by TF, FIXa, FXa and α-thrombin. TF-initiated reactions and their resupply were performed as described previously (Orfeo T et al. J. Biol. Chem., 2008) in either contact pathway inhibited blood ± an inhibitory anti-FXI antibody) or in synthetic coagulation proteome (SCP) mixtures (± FXI), allowing FXI effects on both the TF dependent phase and the resulting procoagulant pool of catalysts to be evaluated. Results. The computational model (± FXI pathway) was validated by showing congruence between computational thrombin generation profiles initiated with 5 pM TF and corresponding SCP reconstructions, which showed the lag phase shortened by 30 to 60 s and maximum thrombin levels increased when FXI was present. Similarly there was good correspondence between computational and SCP thrombin generation when FXIa (4 pM by active site) was the initiator. A computational analysis provided the following ranking of effectiveness in initiating thrombin generation: FXIa>TF>FIXa>FXa>α-thrombin. When tested in contact pathway inhibited blood, addition of 5 pM FXIa (by active site) resulted in clot times and 20 min αTAT levels similar to those observed with 5 pM TF, while similar outcomes required 25 pM FIXa, 100 pM FXa or between 10–100 nM α-thrombin. The computational modeling made clear two consequences of FXI feedback activation. The first was mechanistic, demonstrating that the amplification of thrombin generation was achieved by better coordinating the initial activations of FIX and FVIII; limited early initiation phase activation of FXI (<0.01% zymogen activation) increases the amount of FIXa available during the activation of FVIII, yielding higher concentrations of intrinsic tenase earlier in the initiation phase. The second consequence was increased FIXa accumulation as the reaction proceeds. This prediction was confirmed in two ways: 1) Western blot analysis of SCP reactions containing FXI showed ∼20% consumption of FIX over 20 min compared to no detectable FIX consumption in reactions without FXI; and 2) Resupply of TF-initiated SCP reactions (± 30 nM FXI) demonstrated that both the FVIII dependence and the long-term stability of the observed re-initiation of thrombin generation depended on the presence of FXI. Resupply studies were then performed in contact pathway inhibited blood (N=4 individuals) by using an inhibitory anti-FXI antibody to negate FXI contributions to both the TF-initiated and resupply dynamics. No effect of blocking FXI function on the time courses of αTAT formation was observed in the TF initiated phase. Two of the four individuals showed attenuated αTAT formation upon resupply when FXI function was blocked from the onset of TF initiation. Conclusions. FXIa is a potent initiator of coagulation, and the computational and SCP analyses predict the potential for feedback activation by thrombin after TF initiation to somewhat enhance the propagation phase of thrombin generation and more dramatically enhance the resupply response. However in contact pathway inhibited blood, FXI contributions to Tf-initiated thrombin generation are not discernible and the effect on the resupply response is variable between individuals suggesting additional mechanisms suppressing FXI activation in blood. Disclosures: Mann: Haematologic Technologies: Chairman of the Board, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; corn trypsin inhibitor: Patents & Royalties; NIH, DOD, Baxter: Research Funding; Merck, Daiichi Sankyo, Baxter, GTI: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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