Focal Segmental Glomerulosclerosis Patient Baseline Characteristics in the Sparsentan Phase 3 DUPLEX Study.

Introduction: The phase 3 DUPLEX trial is evaluating sparsentan, a novel, nonimmunosuppressive, single-molecule dual endothelin angiotensin receptor antagonist, in patients with focal segmental glomerulosclerosis (FSGS). Methods: DUPLEX (NCT03493685) is a global, multicenter, randomized, double-blind, parallel-group, active-controlled study evaluating the efficacy and safety of sparsentan 800 mg once daily versus irbesartan 300 mg once daily in patients aged 8 to 75 years (USA/UK) and 18 to 75 years (ex-USA/UK) weighing ≥20 kg with biopsy-proven FSGS or documented genetic mutation in a podocyte protein associated with FSGS, and urine protein-to-creatinine ratio (UP/C) ≥1.5 g/g. Baseline characteristics blinded to treatment allocation are reported descriptively. Results: The primary analysis population includes 371 patients (336 adult, 35 pediatric [<18 years]) who were randomized and received study drug (median age, 42 years). Patients were White (73.0%), Asian (13.2%), Black/African American (6.7%), or Other race (7.0%); and from North America (38.8%), Europe (36.1%), South America (12.7%), or Asia Pacific (12.4%). Baseline median UP/C was 3.0 g/g; 42.6% in nephrotic-range (UP/C >3.5 g/g [adults]; >2.0 g/g [pediatrics]). Patients were evenly distributed across estimated glomerular filtration rate (eGFR) categories corresponding to chronic kidney disease (CKD) stages 1 to 3b. Thirty-three patients (9.4% of 352 evaluable samples) had pathogenic or likely pathogenic (P/LP) variants of genes essential to podocyte structural integrity and function, 27 (7.7%) had P/LP collagen gene (COL4A3/4/5) variants, and 14 (4.0%) had high-risk APOL1 genotypes. Conclusions: Patient enrollment in DUPLEX, the largest interventional study in FSGS to date, will enable important characterization of the treatment effect of sparsentan in a geographically broad and clinically diverse FSGS population.

Sparsentan versus Irbesartan in Focal Segmental Glomerulosclerosis.

BACKGROUND: An unmet need exists for focal segmental glomerulosclerosis (FSGS) treatment. In an 8-week, phase 2 trial, sparsentan, a dual endothelin-angiotensin receptor antagonist, reduced proteinuria in patients with FSGS. The efficacy and safety of longer-term treatment with sparsentan for FSGS are unknown. METHODS: In this phase 3 trial, we enrolled patients with FSGS (without known secondary causes) who were 8 to 75 years of age; patients were randomly assigned to receive sparsentan or irbesartan (active control) for 108 weeks. The surrogate efficacy end point assessed at the prespecified interim analysis at 36 weeks was the FSGS partial remission of proteinuria end point (defined as a urinary protein-to-creatinine ratio of ≤1.5 [with protein and creatinine both measured in grams] and a >40% reduction in the ratio from baseline). The primary efficacy end point was the estimated glomerular filtration rate (eGFR) slope at the time of the final analysis. The change in eGFR from baseline to 4 weeks after the end of treatment (week 112) was a secondary end point. Safety was also evaluated. RESULTS: A total of 371 patients underwent randomization: 184 were assigned to receive sparsentan and 187 to receive irbesartan. At 36 weeks, the percentage of patients with partial remission of proteinuria was 42.0% in the sparsentan group and 26.0% in the irbesartan group (P = 0.009), a response that was sustained through 108 weeks. At the time of the final analysis at week 108, there were no significant between-group differences in the eGFR slope; the between-group difference in total slope (day 1 to week 108) was 0.3 ml per minute per 1.73 m2 of body-surface area per year (95% confidence interval [CI], -1.7 to 2.4), and the between-group difference in the slope from week 6 to week 108 (i.e., chronic slope) was 0.9 ml per minute per 1.73 m2 per year (95% CI, -1.3 to 3.0). The mean change in eGFR from baseline to week 112 was -10.4 ml per minute per 1.73 m2 with sparsentan and -12.1 ml per minute per 1.73 m2 with irbesartan (difference, 1.8 ml per minute per 1.73 m2; 95% CI, -1.4 to 4.9). Sparsentan and irbesartan had similar safety profiles, and the frequency of adverse events was similar in the two groups. CONCLUSIONS: Among patients with FSGS, there were no significant between-group differences in eGFR slope at 108 weeks, despite a greater reduction in proteinuria with sparsentan than with irbesartan. (Funded by Travere Therapeutics; DUPLEX ClinicalTrials.gov number, NCT03493685.).

Efficacy and safety of sparsentan versus irbesartan in patients with IgA nephropathy (PROTECT): 2-year results from a randomised, active-controlled, phase 3 trial.

BACKGROUND: Sparsentan, a novel, non-immunosuppressive, single-molecule, dual endothelin angiotensin receptor antagonist, significantly reduced proteinuria versus irbesartan, an angiotensin II receptor blocker, at 36 weeks (primary endpoint) in patients with immunoglobulin A nephropathy in the phase 3 PROTECT trial's previously reported interim analysis. Here, we report kidney function and outcomes over 110 weeks from the double-blind final analysis. METHODS: PROTECT, a double-blind, randomised, active-controlled, phase 3 study, was done across 134 clinical practice sites in 18 countries throughout the Americas, Asia, and Europe. Patients aged 18 years or older with biopsy-proven primary IgA nephropathy and proteinuria of at least 1·0 g per day despite maximised renin-angiotensin system inhibition for at least 12 weeks were randomly assigned (1:1) to receive sparsentan (target dose 400 mg oral sparsentan once daily) or irbesartan (target dose 300 mg oral irbesartan once daily) based on a permuted-block randomisation method. The primary endpoint was proteinuria change between treatment groups at 36 weeks. Secondary endpoints included rate of change (slope) of the estimated glomerular filtration rate (eGFR), changes in proteinuria, a composite of kidney failure (confirmed 40% eGFR reduction, end-stage kidney disease, or all-cause mortality), and safety and tolerability up to 110 weeks from randomisation. Secondary efficacy outcomes were assessed in the full analysis set and safety was assessed in the safety set, both of which were defined as all patients who were randomly assigned and received at least one dose of randomly assigned study drug. This trial is registered with ClinicalTrials.gov, NCT03762850. FINDINGS: Between Dec 20, 2018, and May 26, 2021, 203 patients were randomly assigned to the sparsentan group and 203 to the irbesartan group. One patient from each group did not receive the study drug and was excluded from the efficacy and safety analyses (282 [70%] of 404 included patients were male and 272 [67%] were White) . Patients in the sparsentan group had a slower rate of eGFR decline than those in the irbesartan group. eGFR chronic 2-year slope (weeks 6-110) was -2·7 mL/min per 1·73 m2 per year versus -3·8 mL/min per 1·73 m2 per year (difference 1·1 mL/min per 1·73 m2 per year, 95% CI 0·1 to 2·1; p=0·037); total 2-year slope (day 1-week 110) was -2·9 mL/min per 1·73 m2 per year versus -3·9 mL/min per 1·73 m2 per year (difference 1·0 mL/min per 1·73 m2 per year, 95% CI -0·03 to 1·94; p=0·058). The significant reduction in proteinuria at 36 weeks with sparsentan was maintained throughout the study period; at 110 weeks, proteinuria, as determined by the change from baseline in urine protein-to-creatinine ratio, was 40% lower in the sparsentan group than in the irbesartan group (-42·8%, 95% CI -49·8 to -35·0, with sparsentan versus -4·4%, -15·8 to 8·7, with irbesartan; geometric least-squares mean ratio 0·60, 95% CI 0·50 to 0·72). The composite kidney failure endpoint was reached by 18 (9%) of 202 patients in the sparsentan group versus 26 (13%) of 202 patients in the irbesartan group (relative risk 0·7, 95% CI 0·4 to 1·2). Treatment-emergent adverse events were well balanced between sparsentan and irbesartan, with no new safety signals. INTERPRETATION: Over 110 weeks, treatment with sparsentan versus maximally titrated irbesartan in patients with IgA nephropathy resulted in significant reductions in proteinuria and preservation of kidney function. FUNDING: Travere Therapeutics.

IgA Nephropathy Patient Baseline Characteristics in the Sparsentan PROTECT Study.

Introduction: Sparsentan is a novel single-molecule dual endothelin angiotensin receptor antagonist with hemodynamic and anti-inflammatory properties and is not an immunosuppressant. The ongoing phase 3 PROTECT trial examines sparsentan in adults with IgA nephropathy (IgAN). Methods: The PROTECT trial (NCT03762850) is a multicenter, international, randomized, double-blind, parallel-group, active-controlled study. The efficacy and safety of sparsentan versus the active control irbesartan is being evaluated in adults with biopsy-proven IgAN and proteinuria ≥1.0 g/d despite maximized treatment with an angiotensin-converting enzyme inhibitor (ACEi) and/or angiotensin receptor blocker (ARB) for at least 12 weeks. Blinded and aggregated baseline characteristics are reported descriptively and compared to contemporary phase 3 trials with patients with IgAN. Results: The primary analysis population includes 404 patients who were randomized and received study drug (median age, 46 years). Enrolled patients were from Europe (53%), Asia Pacific (27%), and North America (20%). Baseline median urinary protein excretion was 1.8 g/d. The range of estimated glomerular filtration rate (eGFR) was broad with the largest proportion of patients (35%) in chronic kidney disease (CKD) stage 3B. Before transitioning to study medication, mean systolic/diastolic blood pressure was 129/82 mm Hg, with the majority of patients (63.4%) receiving the maximum labeled ACEi or ARB dose. Patients in Asian versus non-Asian regions included a higher percentage of females, had lower blood pressures, and included lower proportions of patients with a history of hypertension and baseline antihypertensive treatment. Conclusions: Patient enrollment in PROTECT, with differing racial backgrounds and across CKD stages, will allow for important characterization of the treatment effect of sparsentan in patients with IgAN with proteinuria at high risk of kidney failure.

Sparsentan in patients with IgA nephropathy: a prespecified interim analysis from a randomised, double-blind, active-controlled clinical trial.

BACKGROUND: Sparsentan is a novel, non-immunosuppressive, single-molecule, dual endothelin and angiotensin receptor antagonist being examined in an ongoing phase 3 trial in adults with IgA nephropathy. We report the prespecified interim analysis of the primary proteinuria efficacy endpoint, and safety. METHODS: PROTECT is an international, randomised, double-blind, active-controlled study, being conducted in 134 clinical practice sites in 18 countries. The study examines sparsentan versus irbesartan in adults (aged ≥18 years) with biopsy-proven IgA nephropathy and proteinuria of 1·0 g/day or higher despite maximised renin-angiotensin system inhibitor treatment for at least 12 weeks. Participants were randomly assigned in a 1:1 ratio to receive sparsentan 400 mg once daily or irbesartan 300 mg once daily, stratified by estimated glomerular filtration rate at screening (30 to <60 mL/min per 1·73 m2 and ≥60 mL/min per 1·73 m2) and urine protein excretion at screening (≤1·75 g/day and >1·75 g/day). The primary efficacy endpoint was change from baseline to week 36 in urine protein-creatinine ratio based on a 24-h urine sample, assessed using mixed model repeated measures. Treatment-emergent adverse events (TEAEs) were safety endpoints. All endpoints were examined in all participants who received at least one dose of randomised treatment. The study is ongoing and is registered with ClinicalTrials.gov, NCT03762850. FINDINGS: Between Dec 20, 2018, and May 26, 2021, 404 participants were randomly assigned to sparsentan (n=202) or irbesartan (n=202) and received treatment. At week 36, the geometric least squares mean percent change from baseline in urine protein-creatinine ratio was statistically significantly greater in the sparsentan group (-49·8%) than the irbesartan group (-15·1%), resulting in a between-group relative reduction of 41% (least squares mean ratio=0·59; 95% CI 0·51-0·69; p<0·0001). TEAEs with sparsentan were similar to irbesartan. There were no cases of severe oedema, heart failure, hepatotoxicity, or oedema-related discontinuations. Bodyweight changes from baseline were not different between the sparsentan and irbesartan groups. INTERPRETATION: Once-daily treatment with sparsentan produced meaningful reduction in proteinuria compared with irbesartan in adults with IgA nephropathy. Safety of sparsentan was similar to irbesartan. Future analyses after completion of the 2-year double-blind period will show whether these beneficial effects translate into a long-term nephroprotective potential of sparsentan. FUNDING: Travere Therapeutics.

Study Design of the Phase 3 Sparsentan Versus Irbesartan (DUPLEX) Study in Patients With Focal Segmental Glomerulosclerosis.

INTRODUCTION: Focal segmental glomerulosclerosis (FSGS), a histologic lesion in the kidney caused by varied pathophysiological processes, leads to end-stage kidney disease in a large proportion of patients. Sparsentan is a first-in-class orally active compound combining endothelin type A (ETA) receptor blockade with angiotensin II type 1 (AT1) receptor antagonism in a single molecule. A Randomized, Multicenter, Double-Blind, Parallel, Active-Control Study of the Effects of Sparsentan, a Dual Endothelin Receptor and Angiotensin Receptor Blocker, on Renal Outcomes in Patients With Primary FSGS (DUPLEX) study evaluates the long-term antiproteinuric efficacy, nephroprotective potential, and safety profile of sparsentan compared with an AT1 receptor blocker alone in patients with FSGS. METHODS: DUPLEX is a multicenter, international, phase 3, randomized, double-blind, active-controlled study of sparsentan in patients with FSGS. Approximately 300 patients aged 8 to 75 years, inclusive (United States), and 18 to 75 years, inclusive (outside United States) will be randomized 1:1 to daily treatment with sparsentan or irbesartan. After renin-angiotensin-aldosterone system inhibitor washout, treatment will be administered for 108 weeks, with the final assessment at week 112, four weeks after withdrawal of study drug. RESULTS: The primary endpoint will be the slope of estimated glomerular filtration rate from week 6 to week 108. A novel surrogate efficacy endpoint, the proportion of patients achieving urinary protein-to-creatinine (UP/C) ratio of ≤1.5 g/g and >40% reduction from baseline in UP/C (FSGS partial remission endpoint: FPRE), will be evaluated at a planned interim analysis at week 36. Safety and tolerability of sparsentan will also be assessed. CONCLUSION: The phase 3 DUPLEX study will characterize the long-term antiproteinuric efficacy and nephroprotective potential of dual ETA and AT1 receptor blockade with sparsentan in patients with FSGS.

Endotoxaemia induces resistance to activated protein C in healthy humans.

Systemic inflammation activates the tissue factor/factor VIIa complex (TF/FVIIa), leading to a procoagulant state, which may be enhanced by impairment of physiological anticoagulant pathways, such as the protein C system. Besides impaired protein C activation, resistance to activated protein C (APC) may occur. We studied the effect of endotoxemia on APC resistance, analysed its determinants and evaluated the effect of TF/FVIIa inhibition on endotoxin-induced APC resistance. Sixteen healthy male volunteers participated in the study, eight receiving endotoxin alone and eight receiving the combination of endotoxin and recombinant Nematode Anticoagulant Protein c2 (rNAPc2), a potent inhibitor of TF/FVIIa. Parameters of coagulation were subsequently studied. The sensitivity to APC was determined by two tests: a test based on the endogenous thrombin potential and a test based on the activated partial thromboplastin time. In response to endotoxemia, both tests detected a transient APC resistance that was predominantly mediated by an increase in factor VIII and was not influenced by TF/FVIIa inhibition. In vitro tests confirmed that an increase in factor VIII induced APC resistance, as measured by both tests. This finding suggests that APC resistance might play a role in the procoagulant state occurring during human endotoxemia.

Local activation of the tissue factor-factor VIIa pathway in patients with pneumonia and the effect of inhibition of this pathway in murine pneumococcal pneumonia.

OBJECTIVE: The tissue factor (TF)-factor VIIa (FVIIa) complex not only is essential for activation of blood coagulation but also affect the inflammatory response during sepsis. The objective of this study was to determine the role of TF-FVIIa in pneumonia caused by Streptococcus pneumoniae, the most important causative organism in community-acquired pneumonia and a major cause of sepsis. DESIGN: A controlled, in vivo laboratory study. SETTING: Research laboratory of a health sciences university. PATIENTS AND SUBJECTS: Patients with unilateral community-acquired pneumonia and female BALB/c mice. INTERVENTIONS: Bilateral bronchoalveolar lavage was performed in patients with community-acquired pneumonia. In mice, pneumonia was induced by intranasal inoculation with S. pneumoniae with or without concurrent inhibition of TF-FVIIa by subcutaneous injections of recombinant nematode anticoagulant protein (rNAPc2). MEASUREMENTS AND MAIN RESULTS: Patients with unilateral community-acquired pneumonia demonstrated elevated concentrations of FVIIa, soluble TF, and thrombin-antithrombin complexes in bronchoalveolar lavage fluid obtained from the infected site compared with the uninfected site. Mice with S. pneumoniae pneumonia displayed increased TF expression and fibrin deposits in lungs together with elevated thrombin-antithrombin complex levels in bronchoalveolar lavage fluid; inhibition of TF-FVIIa by rNAPc2 attenuated the procoagulant response in the lung but did not affect host defense, as reflected by an unaltered outgrowth of pneumococci and an unchanged survival. CONCLUSIONS: These data suggest that TF-FVIIa activity contributes to activation of coagulation in the lung during pneumococcal pneumonia but does not play an important role in the antibacterial host defense in this murine model.

Inhibition of the tissue factor/factor VIIa pathway does not influence the inflammatory or antibacterial response to abdominal sepsis induced by Escherichia coli in mice.

BACKGROUND: Anticoagulants have gained increasing attention for the treatment of sepsis. Inhibition of the tissue factor (TF)/factor (F) VIIa pathway has been shown to attenuate the activation of coagulation and to prevent death in a primate model of sepsis caused by gram-negative bacteria. METHODS: To determine the role of the TF/FVIIa complex in the host response to peritonitis, mice received an intraperitoneal injection of live Escherichia coli with or without concurrent treatment with recombinant nematode anticoagulant protein c2 (rNAPc2), a selective inhibitor of the TF/FVIIa pathway. RESULTS: Peritonitis was associated with an increase in the expression of TF at the tissue level and activation of coagulation, as reflected by elevated levels of thrombin-antithrombin complexes and by increased fibrin(ogen) deposition in the liver and lungs. rNAPc2 strongly attenuated this procoagulant response but did not influence the inflammatory response (histopathology, leukocyte recruitment to the peritoneal cavity, and cytokine and chemokine levels). Moreover, rNAPc2 did not alter bacterial outgrowth locally or dissemination of the infection, and survival was not different between rNAPc2-treated mice and control mice. CONCLUSIONS: These data suggest that TF/FVIIa activity contributes to the activation of coagulation during E. coli peritonitis but does not play a role in the inflammatory response or antibacterial host defense.

Treatment of Ebola virus infection with a recombinant inhibitor of factor VIIa/tissue factor: a study in rhesus monkeys.

BACKGROUND: Infection with the Ebola virus induces overexpression of the procoagulant tissue factor in primate monocytes and macrophages, suggesting that inhibition of the tissue-factor pathway could ameliorate the effects of Ebola haemorrhagic fever. Here, we tested the notion that blockade of fVIIa/tissue factor is beneficial after infection with Ebola virus. METHODS: We used a rhesus macaque model of Ebola haemorrhagic fever, which produces near 100% mortality. We administered recombinant nematode anticoagulant protein c2 (rNAPc2), a potent inhibitor of tissue factor-initiated blood coagulation, to the macaques either 10 min (n=6) or 24 h (n=3) after a high-dose lethal injection of Ebola virus. Three animals served as untreated Ebola virus-positive controls. Historical controls were also used in some analyses. FINDINGS: Both treatment regimens prolonged survival time, with a 33% survival rate in each treatment group. Survivors are still alive and healthy after 9 months. All but one of the 17 controls died. The mean survival for the six rNAPc2-treated macaques that died was 11.7 days compared with 8.3 days for untreated controls (p=0.0184). rNAPc2 attenuated the coagulation response as evidenced by modulation of various important coagulation factors, including plasma D dimers, which were reduced in nearly all treated animals; less prominent fibrin deposits and intravascular thromboemboli were observed in tissues of some animals that succumbed to Ebola virus. Furthermore, rNAPc2 attenuated the proinflammatory response with lower plasma concentrations of interleukin 6 and monocyte chemoattractant protein-1 (MCP-1) noted in the treated than in the untreated macaques. INTERPRETATION: Post-exposure protection with rNAPc2 against Ebola virus in primates provides a new foundation for therapeutic regimens that target the disease process rather than viral replication.

Pharmacokinetics and anticoagulant properties of the factor VIIa-tissue factor inhibitor recombinant Nematode Anticoagulant Protein c2 following subcutaneous administration in man. Dependence on the stoichiometric binding to circulating factor X.

Recombinant Nematode Anticoagulant Protein c2 (rNAPc2) is a potent (K(i) =10 pM), inhibitor of the factor VIIa/tissue factor (fVIIa/TF) complex that requires the prerequisite binding to zymogen or activated factor X (fX). In two double blind, place-bo-controlled, sequential dose-escalation phase I studies, rNAPc2 was found to be safe and well tolerated following single and repeat subcutaneous administrations in healthy human male volunteers at doses ranging from 0.3 to 5 micro g/kg. There was a dose-dependent elevation of the prothrombin time reaching almost 4-fold above the baseline value in the highest dose group that directly correlated with rNAPc2 plasma concentration. In contrast, there was little or no effect on the activated partial thromboplastin time, thrombin time or template bleeding time. The pharmacokinetic behavior of rNAPc2 revealed a dose-independent and prolonged elimination half-life (t(1/2)beta) with a mean of >50 hours. A high affinity interaction between rNAPc2 and plasma fX was shown to be essential for the prolonged t(1/2)beta in man using crossed immunoelectrophoresis and was confirmed by exploiting the considerably weaker interaction between rNAPc2 and bovine fX which resulted in an attenuated t(1/2)beta of approximately 1.5 hours in calves. The accumulated data suggests that rNAPc2 is safe and well tolerated following repeat subcutaneous administrations at doses up to 5 micro g/kg in healthy volunteers. In addition, the in vivo fate of rNAPc2 in man appears to be governed by its high affinity interaction with circulating fX. This data supports the continued development of this novel anticoagulant for the prevention and treatment of acute thrombotic disorders.

Recombinant nematode anticoagulant protein c2, an inhibitor of the tissue factor/factor VIIa complex, in patients undergoing elective coronary angioplasty.

OBJECTIVES: We investigated the safety and pharmacodynamics of escalating doses of recombinant nematode anticoagulant protein c2 (rNAPc2) in patients undergoing elective coronary angioplasty. BACKGROUND: Recombinant NAPc2 is a potent inhibitor of the tissue factor/factor VIIa complex, which has the potential to reduce the risk of thrombotic complications in coronary artery disease. METHODS: In a randomized, double-blinded, dose-escalation, multicenter trial, 154 patients received placebo or rNAPc2 at doses of 3.5, 5.0, 7.5, and 10.0 microg/kg body weight as a single subcutaneous administration 2 to 6 h before angioplasty. All patients received aspirin, unfractionated heparin during angioplasty, and clopidogrel in case of stent implantation. RESULTS: Minor bleeding rates for the doses 3.5 to 7.5 microg/kg were comparable to that with placebo (6.7%), whereas an incidence of 26.9% was observed at the 10.0 microg/kg dose level (p < 0.01). Major bleedings occurred in the 5.0 microg/kg (n = 3) and 7.5 microg/kg (n = 1) dose groups. The three patients in the 5.0 microg/kg dose group also received a glycoprotein IIb/IIIa receptor inhibitor at the moment of major bleeding. Systemic thrombin generation, as measured by prothrombin fragment 1+2 (F(1+2)), was suppressed in all rNAPc2 dose groups to levels below pretreatment values for at least 36 h. In the placebo group, a distinct increase of F(1+2) levels was observed following cessation of heparin. CONCLUSIONS: Inhibition of the tissue factor/factor VIIa complex with rNAPc2, at doses up to 7.5 microg/kg, in combination with aspirin, clopidogrel, and unfractionated heparin appears to be a safe and effective strategy to prevent thrombin generation during coronary angioplasty.

Tissue factor/factor VIIa inhibitors block angiogenesis and tumor growth through a nonhemostatic mechanism.

An association between cancer and thrombosis has been recognized for more than a century. However, the manner by which tumor growth is regulated by coagulation in vivo remains unclear. To assess the role of coagulation on tumor growth, in vivo, we tested coagulation inhibitors specific for either tissue factor (TF)/factor VIIa (fVIIa) complexes or factor Xa (fXa) for antitumor activity. Here, we show that two inhibitors of TF/fVIIa, TF pathway inhibitor (TFPI) and the nematode anticoagulant protein rNAPc2, inhibit both primary and metastatic tumor growth in mice. In addition, we show that rNAPc2 is also a potent inhibitor of angiogenesis. In contrast, rNAP5, a second nematode anticoagulant protein that specifically inhibits fXa, does not exhibit antitumor activity. Because the hemostatic activity of TF/fVIIa is mediated through activation of fXa, these data suggest that proteolytic activity of TF/fVIIa promotes tumor growth and angiogenesis through a novel proangiogenic mechanism and independently of hemostasis.

Activation of coagulation by administration of recombinant factor VIIa elicits interleukin 6 (IL-6) and IL-8 release in healthy human subjects.

The activation of coagulation has been shown to contribute to proinflammatory responses in animal and in vitro experiments. Here we report that the activation of coagulation in healthy human subjects by the administration of recombinant factor VIIa also elicits a small but significant increase in the concentrations of interleukin 6 (IL-6) and IL-8 in plasma. This increase was absent when the subjects were pretreated with recombinant nematode anticoagulant protein c2, the inhibitor of tissue factor-factor VIIa.

Inhibition of factor VIIa/tissue factor with nematode anticoagulant protein c2: from unique mechanism to a promising new clinical anticoagulant.

Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent (K(i) = 10 pM) inhibitor of the factor VIIa/tissue factor complex (fVIIa/TF) that involves the pre-requisite binding to either zymogen or activated factor X (fX) prior to the formation of the final quaternary complex with fVIIa/TF. The formation of the binary complex with circulating fX governs the pharmacokinetic profile of rNAPc2 in humans, resulting in a prolonged elimination half-life of >50 h. The clinical antithrombotic potential of rNAPc2 has been evaluated in a phase-II trial in which the incidence of deep-vein thrombosis was reduced over 50% compared to historic controls with low-molecular-weight heparin in patients undergoing knee replacement surgery. A second phase-IIa trial demonstrated the safety of rNAPc2 and the significant suppression of thrombin generation in patients undergoing elective percutaneous coronary intervention treated with standard anticoagulant and antiplatelet therapies. Overall, rNAPc2 is a unique inhibitor of the fVIIa/TF complex and a promising new clinical anticoagulant.