Article

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

Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
Blood (Impact Factor: 10.45). 02/2008; 111(4):1840-7. DOI: 10.1182/blood-2007-06-094136
Source: PubMed

ABSTRACT

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.

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Available from: Robert Brodsky
    • "Therapy with eculizumab (Soliris, Alexion Pharmaceuticals), a humanized monoclonal antibody directed against terminal complement component C5, inhibits MAC formation and thus intravascular lysis (Rother et al., 2007) (Supplemental Figure 1B). Despite the clear benefits of complete blockage of complement TP for PNH patients (Brodsky et al., 2008; Hillmen et al., 2006; Kelly et al., 2011), the high treatment cost, insufficient response in some patients and increased risk for meningococcal infections need to be considered. Whereas the infection risk may be reduced through use of a vaccination panel (Verhave et al., 2014), residual anemia remains an issue for a substantial fraction of patients. "
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    ABSTRACT: Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated cell lysis due to deficiency of GPI-anchored complement regulators. Blockage of the lytic pathway by eculizumab is the only available therapy for PNH patients and shows remarkable benefits, but regularly yields PNH erythrocytes opsonized with fragments of complement protein C3, rendering such erythrocytes prone to extravascular hemolysis. This effect is associated with insufficient responsiveness seen in a subgroup of PNH patients. Novel C3-opsonin targeted complement inhibitors act earlier in the cascade, at the level of activated C3 and are engineered from parts of the natural complement regulator Factor H (FH) or complement receptor 2 (CR2). This inhibitor class comprises three variants of “miniFH” and the clinically developed “FH-CR2” fusion-protein (TT30). We show that the approach of FH-CR2 to target C3-opsonins was more efficient in preventing complement activation induced by foreign surfaces, whereas the miniFH variants were substantially more active in controlling complement on PNH erythrocytes. Subtle differences were noted in the ability of each version of miniFH to protect human PNH cells. Importantly, miniFH and FH-CR2 interfered only minimally with complement-mediated serum killing of bacteria when compared to untargeted inhibition of all complement pathways by eculizumab. Thus, the molecular design of each C3-opsonin targeted complement inhibitor determines its potency in respect to the nature of the activator/surface providing potential functionality in PNH.
    No preview · Article · Jan 2016 · Immunobiology
    • "One of the most important factors affecting the course of the disease is delay to diagnosis and initiation of targeted treatment. Case 3 illustrates that adverse outcomes can be prevented and a good quality of life can be achieved in patients ed appropriately [10] [11]. "
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    ABSTRACT: Paroxysmal nocturnal hemoglobinuria (PNH) is a disease characterized by chronic persistent hemolysis, multi-organ damage and eventually multiple organ failure. PNH develops as a result of increased sensitivity to complement due to an acquired deficiency of certain glycosylphosphatidylinositol (GPI)-linked proteins. The clinical presentation of PNH varies greatly from one patient to another. We present three cases of PNH with different clinical presentations to illustrate the debilitating nature of the disease, possible fatal outcomes, and the need to timely diagnosis and targeted therapy. These cases also underline the need for increased awareness of PNH among relevant healthcare specialties. PNH should be considered as a differential diagnosis in patients with unexplained abdominal pain, dyspnea, renal failure, thrombosis and non-immune hemolytic anemia.
    No preview · Article · Jul 2015 · American Journal of Blood Research
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    • "Upper respiratory system infections, nasopharyngitis , urinary tract infections, wound infections, and fungal infections are encountered in some patients. Eculizumab has also been associated with severe skin eruptions , rash, and kidney failure (Brodsky et al., 2008; Davis, 2008; Knoll et al., 2008). Some of these adverse effects might also be associated with the immunocomplex disease induced by the monoclonal antibody used for the inhibition of the complement cascade. "
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    ABSTRACT: Abstract While the complement system is desired for protective immunity, antibody- and complement-mediated neuromuscular junction (NMJ) destruction, a hallmark of myasthenia gravis (MG) or experimental autoimmune MG (EAMG), is a significant concern. Evidence suggests that the binding of complement factors to the pathogenic anti-acetylcholine receptor (AChR) autoantibody induces the formation of membrane attack complexes (MAC), which ultimately lead to NMJ destruction and muscle weakness. Studies corroborating the evidence show that the complement (C3-C6)-deficient or complement inhibitor (anti-C1q, soluble CR1, anti-C6, and C5 inhibiting peptide)-treated animals are highly resistant to EAMG induction, whereas the deficiency of the naturally occurring complement inhibitors, such as the decay-accelerating factor (DAF), increases EAMG susceptibility. Notably, the complement-inhibited animals do not exhibit significant immunosuppression but only a marginal reduction in the production of certain cytokines and immunoglobulin isotypes. A preliminary clinical trial using antibody-based C5 inhibitor eculizumab has been shown to be of potential use for MG treatment. The inhibition of the classic complement pathway (CCP) alone appears to be enough to suppress EAMG, suggesting that the complement inhibitors targeting specifically the classic pathway could effectively treat MG without causing immunosuppressive and other side effects. For instance, a recent non-antibody-based therapeutic approach selectively targeting the CCP component C2 by small interfering RNA (siRNA) has proven useful in EAMG treatment. The treatment strategies developed for MG might also be beneficial for other complement-mediated autoimmune diseases.
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