Inhibition of C3 with pegcetacoplan results in normalization of hemolysis markers in paroxysmal nocturnal hemoglobinuria

Annals of Hematology - Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disorder characterized by complement-mediated hemolysis. C5 inhibitors (eculizumab/ravulizumab)...     

Erythopoietin treatment during complement inhibition with eculizumab in a patient with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolysis leading to anemia and other clinical manifestations. Transfusions are often required to support hemoglobin at tolerable levels. A PNH patient with aplastic anemia was treated with the complement inhibitor eculizumab, followed by concurrent treatment with recombinant human erythropoietin (rHuEpo). Eculizumab alone reduced hemolysis, increased PNH red blood cell (RBC) mass, and decreased transfusions. Addition of rHuEpo during eculizumab therapy, enhanced erythropoiesis, further increased PNH RBC mass and hemoglobin levels, and rendered the patient transfusion independent for more than two years. These data show that driving erythropoiesis during eculizumab treatment provided further benefit to a patient with PNH and underlying bone marrow failure.     

Treatment of paroxysmal nocturnal hemoglobinuria in the era of eculizumab

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening and debilitating clonal blood disorder caused by an acquired mutation in the phosphatidylinositol glycan (PIG)-A gene. In pluripotent hematopoietic stem cells, this leads to a deficiency of glycosylphosphatidylinositol (GPI)-anchors and GPI-anchored proteins, including the complement regulators CD55 and CD59, on the surface of affected blood cells. PNH red blood cells are highly vulnerable to activation of complement and the formation of the membrane attack complex (MAC). The resulting chronic intravascular hemolysis is the underlying cause of PNH morbidities and mortality. Until recently, the treatment of PNH has been largely empirical and symptomatic with blood transfusions, anticoagulation, and supplementation with folic acid or iron. The only potentially curative treatment is allogeneic stem cell transplantation, but this has severe complications and high mortality and morbidity rates. A new targeted and disease-modifying treatment strategy is the inhibition of the terminal complement cascade with the humanized monoclonal anti-C5 antibody, eculizumab. This effectively inhibits MAC formation and intravascular hemolysis. Eculizumab has shown significant efficacy in controlled studies, with a marked decrease in anemia, fatigue, transfusion requirements, renal impairment, pulmonary hypertension, and risk of severe thromboembolic events, ultimately resulting in improving quality of life and survival.     

Sustained response and long-term safety of eculizumab in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematologic disorder characterized by clonal expansion of red blood cells (RBCs) lacking the ability to inhibit complement-mediated hemolysis. Eculizumab, a humanized monoclonal antibody that binds the C5 complement protein, blocks serum hemolytic activity. This study evaluated the long-term safety and efficacy of eculizumab in 11 patients with PNH during an open-label extension trial. After completion of an initial 12-week study, all patients chose to participate in the 52-week extension study. Eculizumab, administered at 900 mg every 12 to 14 days, was sufficient to completely and consistently block complement activity in all patients. A dramatic reduction in hemolysis was maintained throughout the study, with a decrease in lactate dehydrogenase (LDH) levels from 3110.7 IU/L before treatment to 622.4 IU/L (P = .002). The proportion of PNH type III RBCs increased from 36.7% at baseline to 58.4% (P = .005). The paroxysm rate of days with gross evidence of hemoglobinuria per patient each month decreased from 3.0 during screening to 0.2 (P < .001) during treatment. The median transfusion rate decreased from 1.8 U per patient each month before eculizumab treatment to 0.3 U per patient each month (P = .001) during treatment. Statistically significant improvements in quality-of-life measures were also maintained during the extension study. Eculizumab continued to be safe and well tolerated, and all patients completed the study. The close relationship between sustained terminal complement inhibition, hemolysis, and symptoms was demonstrated.     

Patients with paroxysmal nocturnal hemoglobinuria demonstrate a prothrombotic clotting phenotype which is improved by complement inhibition with eculizumab

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematological disorder, characterized by complement-mediated intravascular hemolysis and thrombosis. The increased incidence of PNH-driven thrombosis is still poorly understood, but unlike other thrombotic disorders, is thought to largely occur through complement-mediated mechanisms. Treatment with a C5 inhibitor, eculizumab, has been shown to significantly reduce the number of thromboembolic events in these patients. Based on previously described links between changes in fibrin clot structure and thrombosis in other disorders, our aim was to investigate clot structure as a possible mechanism of thrombosis in patients with PNH and the anti-thrombotic effects of eculizumab treatment on clot structure. Clot structure, fibrinogen levels and thrombin generation were examined in plasma samples from 82 patients from the National PNH Service in Leeds, UK. Untreated PNH patients were found to have increased levels of fibrinogen and thrombin generation, with subsequent prothrombotic changes in clot structure. No link was found between increasing disease severity and fibrinogen levels, thrombin generation, clot formation or structure. However, eculizumab treated patients showed decreased fibrinogen levels, thrombin generation and clot density, with increasing time spent on treatment augmenting these antithrombotic effects. These data suggest that PNH patients have a prothrombotic clot phenotype due to increased fibrinogen levels and thrombin generation, and that the antithrombotic effects of eculizumab are, in-part, due to reductions in fibrinogen and thrombin generation with downstream effects on clot structure.     

Long-term treatment with eculizumab in paroxysmal nocturnal hemoglobinuria: sustained efficacy and improved survival

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic disorder with increased mortality and morbidity resulting from intravascular hemolysis. Eculizumab, a monoclonal antibody against the complement protein 5, stops the intravascular hemolysis in PNH. We evaluated 79 consecutive patients treated with eculizumab in Leeds between May 2002 and July 2010. The survival of patients treated with eculizumab was not different from age- and sex-matched normal controls (P = .46) but was significantly better than 30 similar patients managed before eculizumab (P = .030). Three patients on eculizumab, all over 50 years old, died of causes unrelated to PNH. Twenty-one patients (27%) had a thrombosis before starting eculizumab (5.6 events per 100 patient-years) compared with 2 thromboses on eculizumab (0.8 events per 100 patient-years; P < .001). Twenty-one patients with no previous thrombosis discontinued warfarin on eculizumab with no thrombotic sequelae. Forty of 61 (66%) patients on eculizumab for more than 12 months achieved transfusion independence. The 12-month mean transfusion requirement reduced from 19.3 units before eculizumab to 5.0 units in the most recent 12 months on eculizumab (P < .001). Eculizumab dramatically alters the natural course of PNH, reducing symptoms and disease complications as well as improving survival to a similar level to that of the general population.     

Effect of the complement inhibitor eculizumab on thromboembolism in patients with paroxysmal nocturnal hemoglobinuria

Hemolysis and hemoglobinemia contribute to serious clinical sequelae in hemolytic disorders. In paroxysmal nocturnal hemoglobinuria (PNH) patients, hemolysis can contribute to thromboembolism (TE), the most feared complication in PNH, and the leading cause of disease-related deaths. We evaluated whether long-term treatment with the complement inhibitor eculizumab reduces the rate of TE in patients with PNH. Clinical trial participants included all patients in the 3 eculizumab PNH clinical studies, which recruited patients between 2002 and 2005 (n = 195); patients from these studies continued treatment in the current multinational open-label extension study. Thromboembolism rate with eculizumab treatment was compared with the pretreatment rate in the same patients. The TE event rate with eculizumab treatment was 1.07 events/100 patient-years compared with 7.37 events/100 patient-years (P < .001) prior to eculizumab treatment (relative reduction, 85%; absolute reduction, 6.3 TE events/100 patient-years). With equalization of the duration of exposure before and during treatment for each patient, TE events were reduced from 39 events before eculizumab to 3 events during eculizumab (P < .001). The TE event rate in antithrombotic-treated patients (n = 103) was reduced from 10.61 to 0.62 events/100 patient-years with eculizumab treatment (P < .001). These results show that eculizumab treatment reduces the risk of clinical thromboembolism in patients with PNH. This study is registered at http://clinicaltrials.gov (study ID no. NCT00122317).     

Improving cytopenia with splenic artery embolization in a patient with paroxysmal nocturnal hemoglobinuria on eculizumab

Paroxysmal nocturnal hemoglobinuria is a rare acquired stem cell disorder characterized by intravascular hemolysis, aplasia and an increased risk of thrombosis. We describe a patient under treatment with the anti-complement antibody eculizumab who developed pancytopenia, requiring blood transfusions, due to massive splenomegaly. The patient underwent two separate splenic embolizations, which reduced the size of the spleen and improved his blood count to the point that blood transfusions were no longer necessary. Splenic embolization was chosen over splenectomy due to the potential postoperative complications of splenectomy, especially that of thrombosis.     

Successful treatment of noncirrhotic portal hypertension with eculizumab in paroxysmal nocturnal hemoglobinuria: A case report

BACKGROUND Idiopathic non-cirrhotic portal hypertension(INCPH) is mainly associated with thrombophilia in Western countries. Paroxysmal nocturnal hemoglobinuria(PNH) is a rare hematologic disease that manifests with hemolytic anemia,thrombosis, and peripheral blood cytopenias. Portal and hepatic venous thrombosis were reported in PNH. A rare case of INCPH complicating PNH is described.CASE SUMMARY A 63-year old woman with a 2-year past medical history of PNH without treatment was admitted because of jaundice and refractory ascites requiring large volume paracentesis. Liver histology revealed portal venopathy with portal fibrosis and sclerosis, nodular regenerative hyperplasia, parenchymal ischemic changes, and focal sinusoidal and perivenular fibrosis without bridging fibrosis or cirrhosis, all indicative of INCPH. The flow cytometry confirmed PNH diagnosis and eculizumab treatment was initiated. Her condition was improved gradually, bilirubin was normalized 6 months following initiation of eculizumab,and 1 year later diuretics were stopped.CONCLUSION Eculizumab improved intravascular hemolysis and reversed clinical manifestations of INCPH in a patient with paroxysmal nocturnal hemoglobinuria.     

Multicenter phase 3 study of the complement inhibitor eculizumab for the treatment of patients with paroxysmal nocturnal hemoglobinuria

The terminal complement inhibitor eculizumab was recently shown to be effective and well tolerated in patients with paroxysmal nocturnal hemoglobinuria (PNH). Here, we extended these observations with results from an open-label, non-placebo-controlled, 52-week, phase 3 clinical safety and efficacy study evaluating eculizumab in a broader PNH patient population. Eculizumab was administered by intravenous infusion at 600 mg every 7 +/- 2 days for 4 weeks; 900 mg 7 +/- 2 days later; followed by 900 mg every 14 +/- 2 days for a total treatment period of 52 weeks. Ninety-seven patients at 33 international sites were enrolled. Patients treated with eculizumab responded with an 87% reduction in hemolysis, as measured by lactate dehydrogenase levels (P < .001). Baseline fatigue scores in the FACIT-Fatigue instrument improved by 12.2 +/- 1.1 points (P < .001). Eculizumab treatment led to an improvement in anemia. The increase in hemoglobin level occurred despite a reduction in transfusion requirements from a median of 8.0 units of packed red cells per patient before treatment to 0.0 units per patient during the study (P < .001). Overall, transfusions were reduced 52% from a mean of 12.3 to 5.9 units of packed red cells per patient. Forty-nine patients (51%) achieved transfusion independence for the entire 52-week period. Improvements in hemolysis, fatigue, and transfusion requirements with eculizumab were independent of baseline levels of hemolysis and degree of thrombocytopenia. Quality of life measures were also broadly improved with eculizumab treatment. This study demonstrates that the beneficial effects of eculizumab treatment in patients with PNH are applicable to a broader population of PNH patients than previously studied. This trial is registered at http://clinicaltrials.gov as NCT00130000.