The story of a unique molecule in hemophilia A: recombinant single-chain factor VIII

ABSTRACTFor patients with hemophilia A, replacement of deficient factor VIII (FVIII) using plasma-derived or recombinant FVIII (rFVIII) products to restore hemostatic control can reduce bleeding complications and preserve musculoskeletal function. Despite the clinical availability of several of these products, challenges remain in the treatment of hemophilia A, the most notable of which are the risk of inhibitor development and the limited half-life of existing FVIII concentrates, which can make prophylaxis burdensome for patients. The use of recombinant protein technology may lead to novel FVIII products with improved properties. This article describes the story of a unique recombinant FVIII protein, rVIII-SingleChain, which is currently in development. In contrast to native FVIII and other commercially available rFVIII preparations, rVIII-SingleChain uses a strong, covalent bond to connect the light and heavy chains, thereby creating a stable, single-chain rFVIII. It has enhanced intrinsic stability, better integrity after reconstitution, and a higher binding affinity to von Willebrand factor. The physicochemical profile of rVIII-SingleChain and preclinical data on its activity and phamacokinetics strengthened the rationale for its clinical investigation. Available data from the AFFINITY clinical trial program are promising; indicating that it has good hemostatic efficacy when used on demand, for prophylaxis, and in the surgical setting, and is also very well tolerated. A pediatric study and an extension study are ongoing as part of the AFFINITY program

Reduced corticosteroid use in adult patients with primary immune thrombocytopenia receiving romiplostim

Adult patients with primary immune thrombocytopenia requiring first-line treatment typically receive corticosteroids, which are associated with low response rates and many potential side effects. In a retrospective analysis of two 6-month, placebo-controlled, phase III trials, corticosteroid use decreased from 30 to 26% among patients treated with the novel thrombopoietin-mimetic romiplostim (n = 83) and remained above 30% for placebo-treated patients (n = 42). Moreover, compared to placebo, patients were spared 7 weeks of corticosteroid treatment for every 100 weeks of romiplostim treatment. Thereafter, corticosteroid use continued to decrease significantly, from 35 to 20%, in patients treated with romiplostim for up to 3 years in an open-label extension study (n = 101), and patients were spared a further 8 weeks of corticosteroid treatment for each additional 100 weeks of romiplostim treatment. Such reductions in corticosteroids may improve health-related quality of life in patients with primary immune thrombocytopenia

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p

Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension

Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nM∗min (443–696) vs. 404 nM∗min (289–573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nM∗min vs. 5040 ± 816 nM∗min, p &lt; 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nM∗min vs. 4824 ± 929 nM∗min, p &lt; 0.001). Thrombin activity levels were 0.6pM in median (0.2–1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p