Anti-C5 antibodies for treatment of neuromyelitis optica lineage disorders

Abstract

Methods of clinical treatment of neuromyelitis optica lineage disorder (NMOSD) using anti-C5 antibodies or antigen-binding fragments thereof are provided.

Description

[0001] This application is a divisional application of the invention patent application which entered the Chinese national stage on June 9, 2022, with application number 202080085425.0, application date December 8, 2020, and invention name “Anti-C5 antibodies for the treatment of neuromyelitis optica spectrum disorders”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 945,644, filed on December 9, 2019, the entire contents of which are incorporated herein by reference for all purposes.

[0003] References to electronically submitted sequence listings The contents of the electronically submitted sequence listing in the ASCII text file (Name: 710476_AX9-007PC_ST25_Sequence_Listing.txt; Size: 56.0 KB; and Creation Date: December 8, 2020) are incorporated herein by reference in their entirety. Background Art

[0004] Neuromyelitis optica spectrum disorder (NMOSD), including neuromyelitis optica (NMO), also known as Devic's Disease or Devic's Syndrome, is a rare, severely disabling autoimmune inflammatory disorder of the central nervous system (CNS) that primarily affects the optic nerves and spinal cord, often leading to blindness, mono- / para- / quadriplegia, and respiratory failure. NMOSD is characterized by a relapsing course from which recovery can be poor due to the progressive accumulation of severe neurological deficits.

[0005] The clinical features of NMO are acute optic neuritis and transverse myelitis, which usually involves more than three vertebral levels and is called longitudinal extensive transverse myelitis (LETM). These clinical events can occur simultaneously or separately. NMO patients may also experience signs and symptoms caused by lesions other than the optic nerve and spinal cord, which are reported in approximately 15% of patients. The clinical manifestations of NMO can be very variable and may not be diagnosed during the first or even second attack.

[0006] Aquaporin 4 (AQP4) is a water channel protein expressed in the CNS, primarily by astrocytes. AQP4 immunoglobulin G (IgG) is an antibody present in 65%-88% of NMOSD patients and is the first biomarker ever specifically identified for an inflammatory demyelinating CNS disorder. Preclinical data suggest that AQP4-IgG triggers the complement cascade, leading to inflammation and formation of the complement-mediated membrane attack complex (MAC). AQP4-IgG-triggered MAC is associated with astrocyte destruction and bystander neuronal damage, but is not seen in the presence of complement inhibitors. With the discovery of NMO-IgG, the diagnostic criteria for NMO were revised in 2006 to include testing for this disease-specific antibody.

[0007] Given that NMO is a disorder that can result in severe disability, the ability to recognize NMO and related disorders and to distinguish them from other demyelinating disorders is important from a clinical perspective. The prognosis of relapsing NMO is poor. The 5-year mortality rate for NMO has been reported to be 30%; 50% maintain permanent severe disability, either visually impaired (blindness in one or both eyes) or unable to walk (requiring a wheelchair). Most deaths are due to neurogenic respiratory failure secondary to high cervical cord or brainstem lesions. Frequent early relapses portend a poor prognosis. Therefore, prevention of relapses is a primary treatment need.

[0008] Despite recent approval of treatment options for NMO ( (Eculizumab was shown to reduce the frequency of relapses in an open-label study of 14 patients with AQP4-IgG-positive disease), but standard treatment options still include supportive care with steroids and other immunosuppressants based on clinical experience and consensus. Acute NMO relapses are usually treated with high-dose IV steroids and plasma exchange (PE), which is often used as salvage therapy for those who do not respond. Current supportive care for relapses uses broad-spectrum or selective B-lymphocyte immunosuppressants.

[0009] Among immunosuppressants, corticosteroids, AZA, mycophenolate mofetil, and rituximab may be most commonly used for long-term prevention. Supportive medication options for NMO may vary depending on regional medical options. In the United States, options include corticosteroids, AZA, MMF, rituximab, and mitoxantrone, while corticosteroids including oral prednisone or pulse high-dose steroids (IV) are common treatments in Japan. A large number of patients (>50%) will continue to have attacks, resulting in additional and permanent neurological deficits and disability. Given the severity of the disease and limited treatment options, there remains a significant unmet medical need for effective and safe treatments for NMO. Summary of the invention

[0010] Described herein are materials and methods for treating NMOSD (eg, NMO). In particular, such materials and methods include C5 inhibitors (eg, ravulizumab).

[0011] In one embodiment, the disclosure relates to a method of treating neuromyelitis optica spectrum disorder (NMOSD) in a human subject in need thereof, the method comprising administering to the human subject an effective amount of an anti-C5 antibody or antigen-binding fragment thereof, comprising a heavy chain sequence of CDR1, CDR2, and CDR3 as set forth in SEQ ID NOs: 19, 18, and 3, respectively, and a light chain sequence of CDR1, CDR2, and CDR3 as set forth in SEQ ID NOs: 4, 5, and 6, respectively, thereby treating NMOSD in the subject, wherein the anti-C5 antibody or antigen-binding fragment thereof comprises an Fc region comprising an amino acid sequence as set forth in SEQ ID NO: 13, wherein the amino acid sequence comprises up to four amino acid substitutions in the amino acid sequence as set forth in SEQ ID NO: 13, and wherein the amino acid substitutions do not include leucine 307 and serine 313. In a particular embodiment, the anti-C5 antibody or antigen-binding fragment thereof comprises a heavy chain variable region as set forth in SEQ ID NO: 12 and a light chain variable region as set forth in SEQ ID NO: 8. In a specific embodiment, the anti-C5 antibody or antigen-binding fragment thereof comprises a heavy chain constant region described in SEQ ID NO: 13. In a specific embodiment, the antibody or antigen-binding fragment thereof comprises a heavy chain polypeptide comprising the amino acid sequence of SEQ ID NO: 14 and a light chain polypeptide comprising the amino acid sequence of SEQ ID NO: 11. In a specific embodiment, the anti-C5 antibody or antigen-binding fragment thereof is soluble in water at pH 7.4 and 25°C at 0.1 nM ≤ K D Affinity dissociation constants (K) in the range of ≤1 nM D ) binds to human C5. In a particular embodiment, the anti-C5 antibody or antigen-binding fragment thereof is at pH 6.0 and 25° C. D≥10nM binds to human C5. In a particular embodiment, the subject is 18 years of age or older. In a particular embodiment, the subject is positive for anti-AQP4 antibodies. In a particular embodiment, the subject has at least one attack or relapse in the past 12 months. In a particular embodiment, the subject's Expanded Disability Status Scale (EDSS) score is ≤7. In a particular embodiment, the anti-C5 antibody is administered in the absence of additional immunosuppressive therapy (IST). In a particular embodiment, the anti-C5 antibody is administered together with at least one IST. In a particular embodiment, at least one IST is selected from the group consisting of: corticosteroids, azathioprine (AZA), mycophenolate mofetil (MMF), methotrexate (MTX) and tacrolimus (TAC). In a particular embodiment, the subject weighs at least 40kg. In a particular embodiment, the therapeutically effective dose is based on the subject's weight. In a particular embodiment, the subject exhibits at least one NMOSD symptom. In a particular embodiment, the subject weighs ≥40 and <60 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 2400 mg on day 1 of the administration cycle; and (b) the anti-C5 antibody is administered at a maintenance dose of 3000 mg on day 15 of the administration cycle and every eight weeks thereafter. In a particular embodiment, the subject weighs ≥60 and <100 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 2700 mg on day 1 of the administration cycle; and (b) the anti-C5 antibody is administered at a maintenance dose of 3300 mg on day 15 of the administration cycle and every eight weeks thereafter. In a particular embodiment, the subject weighs ≥100 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 3000 mg on day 1 of the administration cycle; and (b) the anti-C5 antibody is administered at a maintenance dose of 3600 mg on day 15 of the administration cycle and every eight weeks thereafter. In a particular embodiment, the treatment maintains a serum trough concentration of the anti-C5 antibody or antigen-binding fragment thereof of 100 μg / mL or higher during the administration cycle. In a particular embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody or antigen-binding fragment thereof at 200 μg / mL or higher during the administration cycle. In a particular embodiment, the treatment maintains free C5 concentrations at 0.309 to 0.5 μg / mL or lower. In a particular embodiment, the anti-C5 antibody or antigen-binding fragment thereof is administered at a dose of 3000 mg, 3300 mg, or 3600 mg every eight weeks after the administration cycle for up to two years. In a particular embodiment, the anti-C5 antibody or antigen-binding fragment thereof is formulated for intravenous administration. In a particular embodiment, the patient has not been previously treated with a complement inhibitor. In a particular embodiment, the administration cycle is a total of 26 weeks of treatment. In a particular embodiment, the treatment results in terminal complement inhibition.In a particular embodiment, the subject receives plasma exchange (PE) / plasmapheresis (PP), and wherein the subject optionally receives a supplemental dose of eculizumab, e.g., 1200-1800 mg anti-C5 antibody, within 4 hours after completion of PE / PP. In a particular embodiment, the human subject experiences clinically meaningful improvement in one or more clinical markers of NMOSD progression following administration of eculizumab. In a particular embodiment, the clinical markers of NMOSD progression are selected from the group consisting of: ARR, EDSS score, EQ-5D, SF-36, HAI, and OSIS in a determined trial. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall design of the clinical trial disclosed in this article.

[0013] Figure 2 is a table showing the Timeline of Activities (SoA) for the clinical trials disclosed herein.

[0014] Figure 3 is a table showing the Schedule of Activities (SoA) for the Relapse Assessment Period of the clinical trials disclosed herein.

[0015] Figure 4 is a table showing Kurtzke Expanded Disability Status Scale.

[0016] Figure 5 It is a checklist and diagram of the EuroQoL 5-Dimension (EQ-5D-3L) scale.

[0017] Figure 6 It is the Short Form Health Survey (SF-36).

[0018] Figure 7 It is a checklist for the Hauser Walkability Index (HAI).

[0019] Figure 8 is a chart of the Optic Spinal Injury Score (OSIS).

[0020] Fig. 9 is a table showing the severity of relapse as measured by the Optic Neurospinal Injury Scale.

[0021] Fig.10 It is a checklist of the Columbia-Suicide Severity Rating Scale (C-SSRS) - Screening / Baseline.

[0022] Fig.11 is a checklist of the Columbia-Suicide Severity Rating Scale (C-SSRS) - from the last visit. DETAILED DESCRIPTION

[0023] The present disclosure provides methods for treating neuromyelitis optica spectrum disorder (NMOSD) in a subject in need thereof by administering an antibody that specifically binds complement component 5 (C5). In certain embodiments, the antibody that specifically binds C5 reduces the rate at which C5 is cleaved into C5a and C5b in vivo. In other embodiments, the antibody that specifically binds C5 binds to one or both of the C5a and / or C5b fragments. In any of these embodiments, the antibody that specifically binds C5 reduces the complement cascade at C5, thereby reducing the release of proinflammatory mediators and the formation of lytic pores.

[0024] In certain embodiments, the antibody that specifically binds to C5 is eculizumab or a fragment thereof. Eculizumab (also known as BNJ441, ALXN1210 or ) is an anti-C5 antibody comprising a heavy chain and a light chain having the sequences shown in SEQ ID NO: 14 and 11, respectively, or an antigen-binding fragment and variant thereof. Eculizumab is described in PCT / US2015 / 019225 and U.S. Patent No. 9,079,949, all of which are incorporated herein by reference. Eculizumab selectively binds to human complement protein C5, inhibiting its cleavage into C5a and C5b during complement activation. This inhibition prevents the release of proinflammatory mediators C5a and the formation of cytolytic pore-forming membrane attack complexes (MACs) C5b-9, while retaining proximal or early components of complement activation (e.g., C3 and C3b) that are critical for the opsonization of microorganisms and the clearance of immune complexes.

[0025] definition As used herein, the term "subject" or "patient" is a human patient (eg, a patient with neuromyelitis optica spectrum disorder (NMOSD)). As used herein, the terms "subject" and "patient" are interchangeable.

[0026] As used herein, the phrase "requiring chronic plasma exchange" to maintain clinical stability means that the patient has been regularly treated with plasma exchange therapy at least every 3 months in the past 12 months to manage muscle weakness.

[0027] As used herein, "effective treatment" refers to treatment that produces a beneficial effect, e.g., an improvement in at least one symptom of a disease or disorder. The beneficial effect can take the form of an improvement relative to a baseline, i.e., an improvement relative to a measurement or observation made before treatment was initiated according to the method. Effective treatment can refer to a reduction in at least one symptom of NMOSD.

[0028] The term "effective amount" refers to the amount of an agent that provides a desired biological, therapeutic and / or preventive result. The result can be reduction, improvement, alleviation, mitigation, delay and / or alleviation of one or more signs, symptoms or causes of a disease, or any other desired change in a biological system. In one example, an "effective amount" is an amount of an anti-C5 antibody or antigen-binding fragment thereof that has been clinically demonstrated to alleviate at least one symptom of NMOSD. An effective amount can be administered once or multiple times.

[0029] As used herein, the terms "induction" and "induction phase" are used interchangeably and refer to the first phase of treatment in a clinical trial.

[0030] As used herein, the terms "maintenance" and "maintenance phase" are used interchangeably and refer to the second phase of treatment in a clinical trial. In certain embodiments, treatment is continued or continued until uncontrolled toxicity or disease progression occurs as long as clinical benefit is observed. The maintenance phase of eculizumab administration can last for 6 weeks to the lifetime of the subject. According to other embodiments, the maintenance phase lasts for 26-52, 26-78, 26-104, 26-130, 26-156, 26-182, 26-208 weeks or longer. In other embodiments, the maintenance phase lasts for more than 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156 or 182 weeks. According to other embodiments, the maintenance phase lasts for more than 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 years or more. In certain embodiments, the maintenance phase lasts for the remainder of the subject's life.

[0031] In certain embodiments, the multi-stage dosing regimen of eculizumab includes a third stage. The third stage is used when NMOSD patients must undergo a rescue procedure to maintain clinical stability, including the implementation of plasma exchange / plasmapheresis (PE / PP). In this stage, after plasma exchange, a dose of eculizumab is administered to replace the drug lost in plasma exchange / plasmapheresis. According to certain embodiments, if PE / PP rescue therapy is provided on a non-administration day, supplementary study drug (or placebo) administration is required. In another embodiment, if PE / PP infusion is provided on the administration day, it must be performed before the study drug is administered. In some embodiments, if PE / PP is administered in an unplanned administration visit, the patient receiving PE / PP is administered a supplementary dose within 1, 2, 3, 4, 5, 6, 7 or 8 hours after the completion of the PE / PP period. In some embodiments, if PE / PP is administered in an unplanned administration visit, the patient receiving PE / PP is administered a supplementary dose within 4 hours after the completion of the PE / PP period. In certain embodiments, the amount of the supplementary dose may or may not vary according to PE / PP. In other embodiments, if PE / PP is administered at a scheduled dosing visit, then the regular dosing follows 60 minutes after completion of PE / PP. In certain embodiments, no interval is required between the supplemental dose and the regularly scheduled dose.

[0032] In some embodiments, the supplemental dose of eculizumab is administered at 1000 to 2000 mg. In some embodiments, the supplemental dose of eculizumab is administered at about half of the most recent loading or maintenance dose of eculizumab. In some embodiments, if the most recent loading dose is 2200 mg to 3000 mg eculizumab, the supplemental dose is 1000-1500 mg eculizumab. In some embodiments, if the most recent loading dose is about 2400 mg eculizumab, the supplemental dose is about 1200 mg eculizumab. In some embodiments, if the most recent loading dose is 2400 mg eculizumab, the supplemental dose is 1200 mg eculizumab. In some embodiments, if the most recent loading dose is about 2700 mg eculizumab, the supplemental dose is about 1500 mg eculizumab. In some embodiments, if the most recent loading dose is 2700 mg eculizumab, the supplemental dose is 1500 mg eculizumab. In some embodiments, if the most recent loading dose is about 3000 mg eculizumab, the supplemental dose is about 1500 mg eculizumab. In some embodiments, if the most recent loading dose is 3000 mg eculizumab, the supplemental dose is 1500 mg eculizumab. In some embodiments, if the most recent maintenance dose is about 3000 mg eculizumab, the supplemental dose is about 1500 mg eculizumab. In some embodiments, if the most recent maintenance dose is 3000 mg eculizumab, the supplemental dose is 1500 mg eculizumab. In some embodiments, if the most recent maintenance dose is about 3300 mg eculizumab, the supplemental dose is about 1800 mg eculizumab. In some embodiments, if the most recent maintenance dose is 3300 mg eculizumab, the supplemental dose is 1800 mg eculizumab. In some embodiments, if the most recent maintenance dose is about 3600 mg eculizumab, the supplemental dose is about 1800 mg eculizumab. In some embodiments, if the most recent maintenance dose was 3600 mg eculizumab, the supplemental dose is 1800 mg eculizumab.

[0033] As used herein, the term "loading dose" refers to the initial dose administered to a patient. In some embodiments, the loading dose is 2000-4000 mg of eculizumab. In some embodiments, the loading dose is 2100-2700 mg, 2400-3000 mg, or 2700-3300 mg of eculizumab. In some embodiments, the loading dose is 2300-2500 mg, 2600-2800 mg, or 2900-3100 mg of eculizumab. In some embodiments, the loading dose is about 2400 mg, about 2700 mg, or about 3000 mg of eculizumab. In some embodiments, the loading dose is 2400 mg, 2700 mg, or 3000 mg of eculizumab. The loading dose can be titrated according to body weight.

[0034] In some embodiments, 2100-2700 mg, 2300-2500 mg, about 2400 mg, or 2400 mg of eculizumab is administered to patients weighing greater than or equal to 40 kg but less than 60 kg. In some embodiments, 2400-3000 mg, 2600-2800 mg, about 2700 mg, or 2700 mg of eculizumab is administered to patients weighing greater than or equal to 60 kg but less than 100 kg. In some embodiments, 2700-3300 mg, 2900-3100 mg, about 3000 mg, or 3000 mg of eculizumab is administered to patients weighing greater than 100 kg.

[0035] As used herein, the term "maintenance dose" or "maintenance phase" refers to the dose administered to the patient after the loading dose. In some embodiments, the loading dose is 2000-4000 mg of eculizumab. In some embodiments, the loading dose is 2800-3200 mg, 3100-3500 mg, or 3400-3800 mg of eculizumab. In some embodiments, the loading dose is 2900-3100 mg, 3200-3400 mg, or 3500-3700 mg of eculizumab. In some embodiments, the loading dose is about 3000 mg, about 3300 mg, or about 3600 mg of eculizumab. In some embodiments, the loading dose is 3000 mg, 3300 mg, or 3600 mg of eculizumab. The maintenance dose can be titrated according to body weight.

[0036] In some embodiments, 2800-3200 mg, 2900-3100 mg, about 3000 mg, or 3000 mg of eculizumab is administered to patients weighing greater than or equal to 40 kg but less than 60 kg. In some embodiments, 3100-3500 mg, 3200-3400 mg, about 3300 mg, or 3300 mg of eculizumab is administered to patients weighing greater than or equal to 60 kg but less than 100 kg. In some embodiments, 3400-3800 mg, 3500-3700 mg, about 3600 mg, or 3600 mg of eculizumab is administered to patients weighing greater than 100 kg.

[0037] As used herein, the term "serum trough level" refers to the lowest level of an agent (e.g., an anti-C5 antibody or antigen-binding fragment thereof) or drug present in the serum. In contrast, a "serum peak level" refers to the highest level of an agent in the serum. An "average serum level" refers to the average level of an agent in the serum over time.

[0038] In one embodiment, the treatment regimen is sufficient to maintain a specific serum trough concentration of an anti-C5 antibody or antigen-binding fragment thereof. In one embodiment, for example, the treatment maintains a serum trough concentration of an anti-C5 antibody or antigen-binding fragment thereof of 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 200, 205 , 210, 215, 220, 225, 230, 240, 245, 250, 255, 260, 265, 270, 280, 290, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395 or 400 μg / mL or more. In one embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 100 μg / mL or more. In another embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 150 μg / mL or more. In another embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 200 μg / mL or more. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 250 μg / mL or greater. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 300 μg / mL or greater. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of between 100 μg / mL and 200 μg / mL. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of about 175 μg / mL.

[0039] In another embodiment, to achieve an effective response, to maintain at least 50 μg, 55 μg, 60 μg, 65 μg, 70 μg, 75 μg, 80 μg, 85 μg, 90 μg, 95 μg, 100 μg, 105 μg, 110 μg, 115 μg, 120 μg, 125 μg, 130 μg, 135 μg, 140 μg, 145 μg, 150 μg, 155 μg, 160 μg, 170 μg, 175 μg, 180 μg, 185 μg, 190 μg, 200 μg, 210 μg, 215 μg, 220 μg, 225 μg, 230 μg, 235 μg, 240 μg, 245 μg, 250 μg, 255 μg, 260 μg, 270 μg, 280 μg, 290 μg, 300 μg, 310 μg, 310 μg, 310 μg, 310 μg, 310 μg In one embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains 50 μg to 250 μg of antibody per milliliter of patient blood. In another embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains 100 μg to 200 μg of antibody per milliliter of patient blood. In another embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains about 175 μg of antibody per milliliter of patient blood.

[0040] In another embodiment, in order to obtain an effective response, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a minimum free C5 concentration. In one embodiment, for example, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a free C5 concentration of 0.2 μg / mL, 0.3 μg / mL, 0.4 μg / mL, 0.5 μg / mL or less. In another embodiment, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a free C5 concentration of 0.309 to 0.5 μg / mL or less. In another embodiment, the treatment described herein reduces the free C5 concentration by more than 99% throughout the treatment period. In another embodiment, the treatment reduces the free C5 concentration by more than 99.5% throughout the treatment period.

[0041] The term "terminal complement inhibition" refers to inhibition of the late stage of the complement cascade. In one embodiment, terminal complement inhibition refers to inhibition of the cleavage of complement component 5 ("C5") into C5a and C5b by C5 convertase.

[0042] The term "antibody" describes a polypeptide comprising at least one antibody-derived antigen binding site (e.g., VH / VL region or Fv, or CDR). Antibodies include known antibody forms. For example, an antibody may be a human antibody, a humanized antibody, a camelid antibody, a bispecific antibody, or a chimeric antibody. The antibody may also be a Fab, Fab'2, ScFv, SMIP, an affibody, a nanobody, or a domain antibody. The antibody may also be any of the following isotypes: IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgAsec, IgD, and IgE. The antibody may be a naturally occurring antibody or may be an antibody that has been altered by protein engineering techniques (e.g., by mutation, deletion, substitution, conjugation with a non-antibody portion). The antibody may include, for example, one or more variant amino acids (compared to a naturally occurring antibody) that alter the properties of the antibody (e.g., functional properties). Many such changes are known in the art, and they affect, for example, half-life, effector functions, and / or the patient's immune response to the antibody. The term antibody also includes artificial or engineered polypeptide constructs that contain at least one antibody-derived antigen binding site.

[0043] C5 binding protein The term "antibody" describes a polypeptide comprising at least one antibody-derived antigen binding site (e.g., VH / VL region or Fv, or CDR). Antibodies include known antibody forms. Antibodies can be, for example, human antibodies, humanized antibodies, bispecific antibodies, or chimeric antibodies. Antibodies can also be Fab, Fab'2, ScFv, SMIP, affibody, nanobody, or domain antibody. Antibodies can also be any of the following isotypes: IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgAsec, IgD, or IgE. Antibodies can be naturally occurring antibodies or can be antibodies that have been altered by protein engineering techniques (e.g., by mutation, deletion, substitution, conjugation with non-antibody moieties). Antibodies can include, for example, one or more variant amino acids (compared to naturally occurring antibodies) that change the properties of the antibody (e.g., functional properties). Such changes are known in the art and affect, for example, half-life, effector functions, and / or the patient's immune response to the antibody. The term antibody also includes artificial or engineered polypeptide constructs that contain at least one antibody-derived antigen binding site.

[0044] The anti-C5 antibodies described herein bind complement component C5 (e.g., human C5) and inhibit the cleavage of C5 into fragments C5a and C5b. Anti-C5 antibodies (or VH / VL domains derived therefrom) suitable for use in the methods described herein can be produced using methods known in the art. Alternatively, art-recognized anti-C5 antibodies can be used. Antibodies that compete with these art-recognized antibodies for binding to C5 can also be used.

[0045] Eculizumab (also known as ) is an anti-C5 antibody comprising a heavy chain and a light chain having the sequences shown in SEQ ID NOs: 10 and 11, respectively, or an antigen-binding fragment and variant thereof. Eculizumab is described in PCT / US2007 / 006606, the teachings of which are incorporated herein by reference. In one embodiment, the anti-C5 antibody comprises the CDR1, CDR2, and CDR3 domains of the VH region of eculizumab having the sequence shown in SEQ ID NO: 7, and the CDR1, CDR2, and CDR3 domains of the VL region of eculizumab having the sequence shown in SEQ ID NO: 8. In another embodiment, the antibody comprises the heavy chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NOs: 1, 2, and 3, respectively, and the light chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises the VH and VL regions having the amino acid sequences shown in SEQ ID NOs: 7 and 8, respectively.

[0046] Eculizumab (also known as BNJ441, ALXN1210, or ) is an anti-C5 antibody comprising a heavy chain and a light chain having the sequences shown in SEQ ID NO: 14 and 11, respectively, or an antigen-binding fragment and variant thereof. Eculizumab is described in PCT / US2015 / 019225 and U.S. Patent No. 9,079,949, the teachings of which are incorporated herein by reference. Eculizumab selectively binds to human complement protein C5, inhibiting its cleavage into C5a and C5b during complement activation. This inhibition prevents the release of proinflammatory mediators C5a and the formation of cytolytic pore-forming membrane attack complex (MAC) C5b-9 while retaining the proximal or early components of complement activation (e.g., C3 and C3b) that are critical for the opsonization of microorganisms and the clearance of immune complexes.

[0047] In one embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of eculizumab. Thus, in one embodiment, the antibody comprises the CDR1, CDR2, and CDR3 domains of the eculizumab VH region having the sequence shown in SEQ ID NO: 12, and the CDR1, CDR2, and CDR3 domains of the eculizumab VL region having the sequence shown in SEQ ID NO: 8. In another embodiment, the antibody comprises the heavy chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NO: 19, 18, and 3, respectively, and the light chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NO: 4, 5, and 6, respectively. In another embodiment, the antibody comprises the VH and VL regions having the amino acid sequences shown in SEQ ID NO: 12 and SEQ ID NO: 8, respectively.

[0048] Another exemplary anti-C5 antibody is antibody BNJ421 or an antigen-binding fragment and variant thereof comprising a heavy chain and a light chain having the sequences shown in SEQ ID NOs: 20 and 11, respectively. BNJ421 (also known as ALXN1211) is described in PCT / US2015 / 019225 and U.S. Patent No. 9,079,949, the teachings of which are incorporated herein by reference.

[0049] In other embodiments, the antibody comprises the heavy and light chain CDRs or variable regions of BNJ421. Thus, in one embodiment, the antibody comprises the CDR1, CDR2 and CDR3 domains of the BNJ421 VH region having the sequence shown in SEQ ID NO: 12, and the CDR1, CDR2 and CDR3 domains of the BNJ421 VL region having the sequence shown in SEQ ID NO: 8. In another embodiment, the antibody comprises the heavy chain CDR1, CDR2 and CDR3 domains having the sequences shown in SEQ ID NO: 19, 18 and 3, respectively, and the light chain CDR1, CDR2 and CDR3 domains having the sequences shown in SEQ ID NO: 4, 5 and 6, respectively. In another embodiment, the antibody comprises the VH and VL regions having the amino acid sequences shown in SEQ ID NO: 12 and SEQ ID NO: 8, respectively.

[0050] The exact boundaries of CDRs have been defined differently according to different methods. In some embodiments, the position of CDRs or framework regions within a light chain or heavy chain variable domain may be defined as follows: Kabat et al. [(1991) "Sequences of Proteins of Immunological Interest." NIH Publication No. 91-3242, U.S. Department of Health and Human Services, Bethesda, Maryland]. In this case, CDRs may be referred to as "Kabat CDRs" (e.g., "Kabat LCDR2" or "Kabat HCDR1"). In some embodiments, the position of CDRs of light chain or heavy chain variable regions may be defined as follows: Chothia et al., Nature, 342:877-83, 1989. Therefore, these regions may be referred to as "Chothia CDRs" (e.g., "Chothia LCDR2" or "Chothia HCDR3"). In some embodiments, the position of CDRs of light chain and heavy chain variable regions may be defined as defined by the Kabat-Chothia combined definition. In such embodiments, these regions may be referred to as "combined Kabat-Chothia CDRs." Thomas et al. (Mol. Immunol., 33: 1389-401, 1996) exemplify the identification of CDR boundaries according to the Kabat and Chothia definitions.

[0051] Another exemplary anti-C5 antibody is the 7086 antibody described in U.S. Pat. Nos. 8,241,628 and 8,883,158. In one embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of the 7086 antibody (see U.S. Pat. Nos. 8,241,628 and 8,883,158). In another embodiment, the antibody or antigen-binding fragment thereof comprises a heavy chain CDR1, CDR2, and CDR3 domain having the sequences shown in SEQ ID NOs: 21, 22, and 23, respectively, and a light chain CDR1, CDR2, and CDR3 domain having the sequences shown in SEQ ID NOs: 24, 25, and 26, respectively. In another embodiment, the antibody or antigen-binding fragment thereof comprises a 7086 antibody VH region having the sequence shown in SEQ ID NO: 27 and a 7086 antibody VL region having the sequence shown in SEQ ID NO: 28.

[0052] Another exemplary anti-C5 antibody is the 8110 antibody also described in U.S. Pat. Nos. 8,241,628 and 8,883,158. In one embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of the 8110 antibody. In another embodiment, the antibody or antigen-binding fragment thereof comprises a heavy chain CDR1, CDR2, and CDR3 domain having the sequences shown in SEQ ID NOs: 29, 30, and 31, respectively, and a light chain CDR1, CDR2, and CDR3 domain having the sequences shown in SEQ ID NOs: 32, 33, and 34, respectively. In another embodiment, the antibody comprises a 8110 antibody VH region having the sequence shown in SEQ ID NO: 35 and a 8110 antibody VL region having the sequence shown in SEQ ID NO: 36.

[0053] Another exemplary anti-C5 antibody is the 305LO5 antibody described in US2016 / 0176954 A1. In one embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of the 305LO5 antibody. In another embodiment, the antibody or antigen-binding fragment thereof comprises heavy chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NOs: 37, 38, and 39, respectively, and light chain CDR1, CDR2, and CDR3 domains having the sequences shown in SEQ ID NOs: 40, 41, and 42, respectively. In another embodiment, the antibody comprises a 305LO5 antibody VH region having the sequence shown in SEQ ID NO: 43 and a 305LO5 antibody VL region having the sequence shown in SEQ ID NO: 44.

[0054] Another exemplary anti-C5 antibody is the SKY59 antibody described in Fukuzawa, T. et al. (Sci. Rep., 7:1080, 2017). In one embodiment, the antibody comprises the heavy chain and light chain CDRs or variable regions of the SKY59 antibody. In another embodiment, the antibody or antigen-binding fragment thereof comprises a heavy chain comprising SEQ ID NO:45 and a light chain comprising SEQ ID NO:46.

[0055] Another exemplary anti-C5 antibody is the H4H12166PP antibody described in PCT / US2017 / 037226 and US2017 / 0355757 A1. In one embodiment, the antibody comprises the heavy chain and light chain CDRs or variable regions of the H4H12166PP antibody. In another embodiment, the antibody or its antigen-binding fragment comprises the H4H12166PP antibody VH region having the sequence shown in SEQ ID NO:47 and the H4H12166PP antibody VL region having the sequence shown in SEQ ID NO:48. In another embodiment, the antibody or its antigen-binding fragment comprises a heavy chain comprising SEQ ID NO:49 and a light chain comprising SEQ ID NO:50.

[0056] In one embodiment, the patient is treated with eculizumab and then switched to treatment with 7086 antibody, 8110 antibody, 305LO5 antibody, SKY59 antibody, H4H12166PP antibody or eculizumab. In another embodiment, the patient is switched from an anti-C5 antibody (e.g., eculizumab, 7086 antibody, 8110 antibody, 305LO5 antibody, SKY59 antibody or H4H12166PP antibody) to another anti-C5 antibody (e.g., eculizumab) during treatment. In a particular embodiment, the patient is switched from eculizumab to eculizumab during treatment.

[0057] In some embodiments, the anti-C5 antibodies described herein comprise a heavy chain CDR1 comprising or consisting of the following amino acid sequence: GHIFSNYWIQ (SEQ ID NO: 19). In some embodiments, the anti-C5 antibodies described herein comprise a heavy chain CDR2 comprising or consisting of the following amino acid sequence: EILPGSGHTEYTENFKD (SEQ ID NO: 18). In some embodiments, the anti-C5 antibodies described herein comprise a heavy chain variable region comprising the following amino acid sequence: QVQLVQSGAEVKKPGASVKVSCKASGHIFSNYWIQWVRQAPGQGLEWMGEILPGSGHTE YTENFKDRVTMTRDTSTSTVYMELSSLRSEDTAVYYCARYFFGSSPNWYFDVWGQGTLV TVSS (SEQ ID NO: 12).

[0058] In some embodiments, an anti-C5 antibody described herein comprises a light chain variable region comprising the following amino acid sequence: DIQMTQSPSSLSASVGDRVTITCGASENIYGALNWYQQKPGKAPKLLIYGATNLADGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQNVLNTPLTFGQGTKVEIK (SEQ ID NO: 8).

[0059] In some embodiments, the anti-C5 antibodies described herein may include a variant human Fc constant region that binds to a human neonatal Fc receptor (FcRn), and the affinity of the human neonatal Fc receptor is greater than the affinity of the natural human Fc constant region from which the variant human Fc constant region is derived. For example, the Fc constant region may include one or more (e.g., two, three, four, five, six, seven or eight or more) amino acid substitutions relative to the natural human Fc constant region from which the variant human Fc constant region is derived. The substitution can increase the binding affinity of the IgG antibody containing the variant Fc constant region to FcRn at pH 6.0 while maintaining the pH dependence of the interaction. Methods for testing whether one or more substitutions in the Fc constant region of an antibody increase the affinity of the Fc constant region to FcRn at pH 6.0 (while maintaining the pH dependence of the interaction) are known in the art and are illustrated in the working examples (PCT / US2015 / 019225 and U.S. Patent No. 9,079,949, the disclosure of each of which is incorporated herein by reference in its entirety).

[0060] Substitutions that enhance the binding affinity of an antibody Fc constant region for FcRn are known in the art and include, for example, the M252Y / S254T / T256E triple substitution described by (1) Dall'Acqua, W. et al. (J. Biol. Chem., 281:23514-24, 2006); (2) Hinton, P. et al. (J. Biol. Chem., 279:621-64, 2006). 3-6, 2004) and Hinton, P. et al. (J. Immunol., 176:346-56, 2006); and (3) N434A or T307 / E380A / N434A substitutions described in Petkova, S. et al. (Int. Immunol., 18:1759-69, 2006). Additional substitution pairs: P257I / Q311I, P257I / N434H and D376V / N434H have also been described (Datta-Mannan, A. et al., J. Biol. Chem., 282:1709-17, 2007, the disclosure of which is incorporated herein by reference in its entirety).

[0061] In some embodiments, the variant constant region has a substitution for valine at EU amino acid residue 255. In some embodiments, the variant constant region has a substitution for asparagine at EU amino acid residue 309. In some embodiments, the variant constant region has a substitution for isoleucine at EU amino acid residue 312. In some embodiments, the variant constant region has a substitution at EU amino acid residue 386.

[0062] In some embodiments, the variant Fc constant region comprises no more than 30 (e.g., no more than 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3 or 2) amino acid substitutions, insertions or deletions relative to the native constant region from which it is derived. In some embodiments, the variant Fc constant region comprises one or more amino acid substitutions selected from the following group of components: M252Y, S254T, T256E, N434S, M428L, V259I, T250I and V308F. In some embodiments, the variant human Fc constant region comprises methionine at position 428 and asparagine at position 434, each of which is numbered in EU. In some embodiments, the variant Fc constant region comprises a 428L / 434S double substitution, such as described in, for example, U.S. Patent No. 8,088,376.

[0063] In some embodiments, the precise positions of these mutations may be offset from the natural human Fc constant region positions due to antibody engineering. For example, when used in an IgG2 / 4 chimeric Fc, the 428L / 434S double substitution may correspond to the 429L and 435S in the M429L and N435S variants found in BNJ441 (eculizumab) and described in U.S. Pat. No. 9,079,949 (the disclosure of which is incorporated herein by reference in its entirety).

[0064] In some embodiments, the variant constant region comprises a substitution at amino acid position 237, 238, 239, 248, 250, 252, 254, 255, 256, 257, 258, 265, 270, 286, 289, 297, 298, 303, 305, 307, 308, 309, 311, 312, 314, 315, 317, 325, 332, 334, 360, 376, 380, 382, ​​384, 385, 386, 387, 389, 424, 428, 433, 434, or 436 (EU numbering) relative to a native human Fc constant region. In some embodiments, the substitution is selected from the group consisting of: methionine for glycine at position 237; alanine for proline at position 238; lysine for serine at position 239; isoleucine for lysine at position 248; alanine, phenylalanine, isoleucine, methionine, glutamine, serine, valine, tryptophan, or tyrosine for threonine at position 250; phenylalanine, tryptophan, or tyrosine for methionine at position 252; threonine for serine at position 254; glutamic acid for arginine at position 255; arginine for arginine at position 256; threonine for arginine at position 257; arginine for arginine at position 258; arginine for arginine at position 259; arginine for arginine at position 260; arginine for arginine at position 261; arginine for arginine at position 262; arginine for arginine at position 263; arginine for arginine at position 264; arginine for arginine at position 265; arginine for arginine at position 266; arginine for arginine at position 267; arginine for arginine at position 268; arginine for arginine at position 269; arginine for arginine at position 270; arginine for arginine at position 271; arginine for arginine at position 272 Aspartic acid, glutamic acid or glutamine substituted for threonine; alanine, glycine, isoleucine, leucine, methionine, asparagine, serine, threonine or valine substituted for proline at position 257; histidine substituted for glutamic acid at position 258; alanine substituted for aspartic acid at position 265; phenylalanine substituted for aspartic acid at position 270; alanine or glutamic acid substituted for asparagine at position 286; histidine substituted for threonine at position 289; alanine substituted for asparagine at position 297; glycine substituted for serine at position 298; alanine substituted for valine at position 303 ; substitution of alanine for valine at position 305; substitution of alanine, aspartic acid, phenylalanine, glycine, histidine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, serine, valine, tryptophan or tyrosine for threonine at position 307; substitution of alanine, phenylalanine, isoleucine, leucine, methionine, proline, glutamine or threonine for valine at position 308; substitution of alanine, aspartic acid, glutamic acid, proline or arginine for leucine or valine at position 309; substitution of alanine, histidine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine or threonine for leucine or valine at position 311; substituted for glutamine at position 312 by alanine or histidine; substituted for aspartic acid at position 314 by lysine or arginine; substituted for asparagine at position 315 by alanine or histidine; substituted for lysine at position 317 by alanine; substituted for asparagine at position 325 by glycine; substituted for isoleucine at position 332 by valine; substituted for lysine at position 334 by leucine; substituted for lysine at position 360 by histidine; substituted for aspartic acid at position 376 by alanine; substituted for glutamic acid at position 380 by alanine; substituted for glutamic acid at position 382 by alanine;Substitution of alanine for asparagine or serine at position 384; substitution of aspartic acid or histidine for glycine at position 385; substitution of proline for glutamine at position 386; substitution of glutamic acid for proline at position 387; substitution of alanine or serine for asparagine at position 389; substitution of alanine for serine at position 424; substitution of alanine, aspartic acid, phenylalanine, glycine, histidine, isoleucine, lysine, leucine, asparagine, proline, glutamine, serine, threonine, valine, tryptophan or tyrosine for methionine at position 428; substitution of lysine for histidine at position 433; substitution of alanine, phenylalanine, histidine, serine, tryptophan or tyrosine for asparagine at position 434; and substitution of histidine for tyrosine or phenylalanine at position 436, all using EU numbering. ;

[0065] In some embodiments, suitable anti-C5 antibodies for use in the methods described herein include a heavy chain polypeptide comprising the amino acid sequence described in SEQ ID NO: 14 and / or a light chain polypeptide comprising the amino acid sequence described in SEQ ID NO: 11. Alternatively, in some embodiments, the anti-C5 antibodies for use in the methods described herein include a heavy chain polypeptide comprising the amino acid sequence described in SEQ ID NO: 20 and / or a light chain polypeptide comprising the amino acid sequence described in SEQ ID NO: 11.

[0066] In one embodiment, the antibody binds to C5 with an affinity dissociation constant (KD) of at least 0.1 (e.g., at least 0.15, 0.175, 0.2, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, or 0.975) nM at pH 7.4 and 25°C (and, otherwise under physiological conditions). In some embodiments, the KD of the anti-C5 antibody or antigen-binding fragment thereof is no greater than 1 nM (e.g., no greater than 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, or 0.2 nM).

[0067] In other embodiments, [(antibodies against C5 at pH 6.0 and 25°C K D ) / (K of antibody against C5 at pH 7.4 and 25°C D)] greater than 21 (e.g., greater than 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550 40, 250, 260, 270, 280, 290, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500 or 8000).

[0068] Methods for determining whether an antibody binds to a protein antigen and / or the affinity of an antibody for a protein antigen are known in the art. For example, the binding of an antibody to a protein antigen can be detected and / or quantified using a variety of techniques, such as, but not limited to, Western blot, dot blot, surface plasmon resonance (SPR) methods (e.g., BIAcore system; Pharmacia Biosensor AB, Uppsala, Sweden and Piscataway, New Jersey), or enzyme-linked immunosorbent assay (ELISA) (Benny KC Lo (2004) "Antibody Engineering: Methods and Protocols," Humana Press (ISBN: 1588290921); Johne, B. et al., J. Immunol. Meth., 160: 191-8, 1993; U. et al., Ann. Biol. Clin., 51:19-26, 1993; and U. et al., Biotechniques, 11:620-7, 1991). In addition, methods for measuring affinities (eg, dissociation and association constants) are described in the working examples.

[0069] As used herein, the term “k a ” refers to the rate constant for the binding of an antibody to an antigen. The term “k d ” refers to the rate constant for the dissociation of an antibody from an antibody / antigen complex. And the term “K D ” refers to the equilibrium dissociation constant of the antibody-antigen interaction. The equilibrium dissociation constant is derived from the ratio of the kinetic rate constants, K D =ka / k d Such assays are preferably measured at 25°C or 37°C (see working examples). For example, the kinetics of antibody binding to human C5 can be determined at pH 8.0, 7.4, 7.0, 6.5 and 6.0 by surface plasmon resonance (SPR) on a BIAcore 3000 instrument using an anti-Fc capture method to immobilize the antibody.

[0070] In one embodiment, the anti-C5 antibody or its antigen-binding fragment blocks the production or activity of C5a and / or C5b active fragments of C5 protein (e.g., human C5 protein). Through this blocking effect, the antibody inhibits, for example, the proinflammatory effects of C5a and the generation of C5b-9 membrane attack complex (MAC) on the cell surface.

[0071] Methods for determining whether a particular antibody described herein inhibits C5 cleavage are known in the art. Inhibition of human complement component C5 can reduce the cytolytic capacity of complement in a subject's body fluid. This reduction in the cytolytic capacity of complement present in one or more body fluids can be measured by methods known in the art, such as by conventional hemolysis assays, such as those described in Kabat and Mayer (eds.), "Experimental Immunochemistry," 2nd ed., 135-240, Springfield, IL, CC Thomas (1961), pp. 135-139, or conventional variants of such assays, such as chicken erythrocyte hemolysis (Hillmen, P. et al., N. Engl. J. Med., 350:552-9, 2004). Methods for determining whether a candidate compound inhibits the cleavage of human C5 into C5a and C5b forms are known in the art (Evans, M. et al., Mol. Immunol. [Molecular Immunology], 32: 1183-95, 1995). The concentration and / or physiological activity of C5a and C5b in body fluids can be measured, for example, by methods known in the art. For C5b, one or more hemolytic assays for soluble C5b-9 as discussed herein can be used. Other assays known in the art can also be used. Using these or other suitable types of assays, candidate agents that can inhibit human complement component C5 can be screened.

[0072] Immunological techniques such as, but not limited to, ELISA can be used to measure the protein concentration of C5 and / or its cleavage products to determine the ability of anti-C5 antibodies or antigen-binding fragments thereof to inhibit the conversion of C5 to biologically active products. In some embodiments, the production of C5a is measured. In some embodiments, C5b-9 neo-epitope-specific antibodies are used to detect the formation of terminal complement.

[0073] In some embodiments, C5 activity or its inhibition is quantified using the CH50eq assay. The CH50eq assay is a method for measuring total classical complement activity in serum. The test is a lysis assay that uses antibody-sensitized erythrocytes as activators of the classical complement pathway and various dilutions of test serum to determine the amount required to provide 50% lysis (CH50). For example, a spectrophotometer can be used to determine the percentage of hemolysis. The CH50eq assay provides an indirect measurement of the formation of the terminal complement complex (TCC) because the TCC itself is directly responsible for the measured hemolysis.

[0074] For example, inhibition associated with terminal complement activity includes a reduction of at least 5% (e.g., at least 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60%) of terminal complement activity compared to the effect of a control antibody (or antigen-binding fragment thereof) under similar conditions and equimolar concentrations. As used herein, significant inhibition refers to a given activity (e.g., terminal complement activity) being inhibited by at least 40% (e.g., at least 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95% or more). In some embodiments, the anti-C5 antibodies described herein contain one or more amino acid substitutions relative to the CDRs of eculizumab (i.e., SEQ ID NOs: 1-6), but still retain at least 30% (e.g., at least 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%) of the complement inhibition activity of eculizumab.

[0075] The anti-C5 antibodies described herein have a serum half-life of at least 20 days (e.g., at least 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, or 55 days) in humans. In another embodiment, the anti-C5 antibodies described herein have a serum half-life of at least 40 days in humans. In another embodiment, the anti-C5 antibodies described herein have a serum half-life of about 43 days in humans. In another embodiment, the anti-C5 antibodies described herein have a serum half-life of 39-48 days in humans. Methods for measuring the serum half-life of antibodies are known in the art. In some embodiments, the serum half-life of an anti-C5 antibody or antigen-binding fragment thereof described herein is at least 20% greater (e.g., at least 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 250, 300, 400, or 500%) than the serum half-life of eculizumab, e.g., as measured in one of the mouse model systems described in the working Examples (e.g., a C5-deficient / NOD / scid mouse or an hFcRn transgenic mouse model system).

[0076] In one embodiment, the antibody competes with the antibodies described herein for binding to the same epitope on C5 and / or competes for binding to the same epitope on C5. The term "binding to the same epitope" with respect to two or more antibodies refers to the antibody binding to the same amino acid residue fragment, as determined by a given method. Techniques for determining whether an antibody binds to the "same epitope on C5" as an antibody described herein include, for example, epitope mapping methods, such as X-ray analysis of antigen crystals: antibody complexes providing atomic resolution of epitopes and hydrogen / deuterium exchange mass spectrometry (HDX-MS). Other methods monitor the binding of antibodies to peptide antigen fragments or mutant variants of antigens, in which loss of binding due to modification of amino acid residues within the antigen sequence is generally considered to be an indication of epitope components. In addition, computational combinatorial methods for epitope mapping can also be used. These methods rely on the ability of the target antibody to affinity isolate specific short peptides from a combinatorial phage display peptide library. Antibodies with the same VH and VL or the same CDR1, 2 and 3 sequences are expected to bind to the same epitope.

[0077] An antibody that "competes with another antibody for binding to a target" refers to an antibody that inhibits (partially or completely) the binding of another antibody to a target. Whether two antibodies compete with each other to bind to a target, i.e., whether one antibody inhibits the binding of another antibody to a target and to what extent, can be determined using known competition experiments. In certain embodiments, an antibody competes with another antibody and inhibits the binding of the other antibody to a target by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%. The level of inhibition or competition may vary, depending on which antibody is a "blocking antibody" (i.e., a cold antibody that is first incubated with the target). Competitive antibodies bind to the same epitope, overlapping epitopes, or adjacent epitopes (e.g., as indicated by steric hindrance).

[0078] The anti-C5 antibodies or antigen-binding fragments thereof described herein for use in the methods described herein can be produced using a variety of techniques recognized in the art. Monoclonal antibodies can be obtained by various techniques familiar to those skilled in the art. Briefly, spleen cells from an animal immunized with the desired antigen are immortalized (eg, by fusion with myeloma cells) and then cloned. G. & Milstein, C., Eur. J. Immunol. [European Journal of Immunology], 6: 511-9, 1976). Alternative immortalization methods include transformation with Epstein-Barr virus, oncogenes or retroviruses or other methods well known in the art. Colonies from single immortalized cells are screened for the production of antibodies with the desired specificity and affinity for the antigen, and the yield of monoclonal antibodies produced by these cells can be increased by various techniques, including injection into the peritoneal cavity of a vertebrate host. Alternatively, DNA sequences encoding monoclonal antibodies or binding fragments thereof can be isolated by screening DNA libraries from human B cells (Huse, W. et al., Science [Science], 246: 1275-81, 1989).

[0079] Composition Pharmaceutical compositions comprising eculizumab, alone or in combination with a prophylactic agent, a therapeutic agent, and / or a pharmaceutically acceptable carrier are provided. The pharmaceutical compositions comprising eculizumab provided herein are used, but not limited to, for diagnosing, detecting, or monitoring a disorder, preventing, treating, managing, or ameliorating a disorder or one or more symptoms thereof, and / or for research. The formulation of the pharmaceutical composition, alone or in combination with a prophylactic agent, a therapeutic agent, and / or a pharmaceutically acceptable carrier is known to those skilled in the art.

[0080] In one embodiment, the composition comprises an anti-C5 antibody comprising CDR1, CDR2 and CDR3 domains in a heavy chain variable region having a sequence as shown in SEQ ID NO: 12 and CDR1, CDR2 and CDR3 domains in a light chain variable region having a sequence as shown in SEQ ID NO: 8. In another embodiment, the anti-C5 antibody comprises a heavy chain and a light chain having sequences as shown in SEQ ID NO: 14 and 11, respectively.

[0081] The composition can be formulated as a pharmaceutical solution, for example, for administration to a subject to treat or prevent NMOSD. The pharmaceutical composition generally includes a pharmaceutically acceptable carrier. As used herein, "pharmaceutically acceptable carrier" refers to and includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, etc. that are physiologically compatible. The composition can include pharmaceutically acceptable salts, such as acid addition salts or base addition salts, sugars, carbohydrates, polyols and / or tonicity modifiers.

[0082] The composition can be formulated according to standard methods. Pharmaceutical formulation is a recognized technology and is further described, for example, in Gennaro (2000) "Remington: The Science and Practice of Pharmacy," 20th edition, Lippincott, Williams & Wilkins (ISBN: 0683306472); Ansel et al. (1999) "Pharmaceutical Dosage Forms and Drug Delivery Systems," 7th edition, Lippincott Williams & Wilkins (ISBN: 0683305727); and Kibbe (2000) "Handbook of Pharmaceutical Excipients American Pharmaceutical Association," 3rd edition (ISBN: 091733096X). In some embodiments, the composition can be formulated, for example, as a buffer solution of a suitable concentration and suitable for storage at 2-8°C (e.g., 4°C). In some embodiments, the composition can be formulated for storage at a temperature below 0°C (e.g., -20°C or -80°C). In some embodiments, the composition can be formulated for storage at 2-8°C (e.g., 4°C) for up to 2 years (e.g., one month, two months, three months, four months, five months, six months, seven months, eight months, nine months, 10 months, 11 months, 1 year ... month, 1 month, 1 month, 1 / 2 years or 2 years). Thus, in some embodiments, the compositions described herein are stable when stored at 2-8°C (eg, 4°C) for at least 1 year.

[0083] Pharmaceutical compositions can be in various forms. These forms include, for example, liquid, semisolid and solid dosage forms, such as liquid solutions (e.g., injectable and infusible solutions), dispersants or suspensoids, tablets, pills, powders, liposomes and suppositories. The preferred form depends in part on the intended mode of administration and therapeutic application. For example, a composition containing a composition for systemic or local delivery can be in the form of an injectable or infusible solution. The composition can be formulated to be administered by parenteral means (e.g., intravenous, subcutaneous, intraperitoneal or intramuscular injection). As used herein, "parenteral administration," "parenterally administered," and other grammatically equivalent phrases refer to modes of administration other than enteral and topical administration, usually by injection, and include, but are not limited to, intravenous, intranasal, intraocular, pulmonary, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intrapulmonary, intraperitoneal, transtracheal, subcutaneous, subcutaneous, intraarticular, subcapsular, subarachnoid, intraspinal, epidural, intracerebral, intracranial, intracarotid, and intrasternal injection and infusion. In one embodiment, the antibody is formulated for intravenous administration.

[0084] An exemplary, non-limiting range of a therapeutically or prophylactically effective amount of eculizumab or other anti-C5 antibodies such as eculizumab, BNJ 421, 7086, 8110, SKY59, and H4H12166PP provided herein is 600-5000 mg, for example 900-2000 mg. It should be noted that dosage values ​​may vary with the type and severity of the condition to be alleviated. It should be further understood that for any particular subject, a particular dosage regimen may be adjusted over time according to individual needs and the professional judgment of the person administering or supervising the administration of the composition, and that the dosage ranges described herein are exemplary only and are not intended to limit the scope or practice of the claimed method.

[0085] Treatments for neuromyelitis optica The present disclosure provides methods for treating subjects with NMOSD by administering an antibody that specifically binds to C5. As used herein, the terms "subject" and "patient" are interchangeable. In certain embodiments, the subject and / or patient is a mammal, including, for example, a primate, e.g., a human, a rodent, a lagomorph, a camelid, an ungulate, a canine, and a feline. In certain embodiments, the subject or patient with NMOSD described herein is a human.

[0086] NMOSD is characterized by a relapsing course from which recovery can be poor due to the progressive accumulation of severe neurological deficits. Neuromyelitis optica (NMO), also known as Devic's Disease or Devic's Syndrome, is part of NMOSD and is a rare, severely disabling autoimmune inflammatory disorder of the central nervous system (CNS) that primarily affects the optic nerves and spinal cord, typically leading to blindness, mono- / para- / quadriplegia, and respiratory failure.

[0087] In some embodiments, NMO is characterized by NMO-IgG antibodies against aquaporin 4 (anti-AQP4). In some embodiments, a subset of NMO patients are anti-AQP4 + In another embodiment, a subset of NMO patients is resistant to MOG + (Myelin oligodendrocyte glycoprotein).

[0088] In some embodiments, AQP4 autoantibodies are present in patients with NMO-like symptoms that do not meet the clinical requirements for a diagnosis of NMO. In some embodiments, one of the requirements for being diagnosed with NMO is recurrent and concurrent inflammation of the optic nerve and spinal cord.

[0089] In some embodiments, NMOSD includes limited forms of Devic's disease, such as single or recurrent episodes of longitudinally extensive myelitis, and bilateral simultaneous or recurrent optic neuritis. In some embodiments, NMOSD encompasses Asian optico-spinal MS (OSMS), or AQP4 + OSMS. In some embodiments, NMOSD further encompasses longitudinally widespread myelitis or optic neuritis associated with systemic autoimmune disease, as well as optic neuritis or myelitis associated with lesions in specific brain regions such as the hypothalamus, periventricular nuclei, and brainstem.

[0090] In certain embodiments, treatment of NMOSD includes alleviating or ameliorating one or more symptoms associated with NMOSD. Symptoms associated with NMOSD include visual disturbances, decreased vision, visual field loss, color vision loss, spinal cord dysfunction, muscle weakness, decreased sensation, and loss of bladder or bowel control.

[0091] In other embodiments, the treatment of NMOSD includes improving clinical markers of NMOSD progression. These markers include, for example, time to relapse, annual relapse rate (ARR), expanded disability rating scale score (EDSS), modified Rankin scale (mRS), quality of life (ED-5D), Hauser walking index (HAI), visual acuity changes using Snellen charts, and relapse severity using optic spinal injury score (OSIS).

[0092] NMOSD relapse is evidenced by the occurrence of NMOSD symptoms in a subject who had previously successfully remitted symptoms. Relapse is manifested by the appearance or worsening of symptoms related to vision or sensation. Visual changes associated with NMOSD relapse include rapid onset of eye pain, blurred vision, colors not looking right, loss of visual field, spots or dots in the visual field, lights flickering or flashing in the visual field, difficulty concentrating, difficulty reading, and a feeling that the visual field does not seem right. Sensory changes associated with NMOSD relapse include pain, tingling, numbness, the arms, legs, or face seeming to be asleep, loss of sense of position in space, loss of sensation in the extremities, pain with slight touch, pain caused by clothing or sheets, and the subject being unable to detect an injury to the subject. The annualized relapse rate (ARR) is the average number of relapses per year.

[0093] In certain embodiments, the subject treated for NMOSD has relapsed three or more times during the 24 months prior to administration of eculizumab. In other embodiments, the subject treated for NMO has relapsed 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more times during the 24 months prior to administration of eculizumab. In certain embodiments, the subject treated for NMOSD has an ARR of 1.0 or greater during the 24 months prior to administration of eculizumab. In other embodiments, the ARR of the subject treated for NMOSD is at least 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 25, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 or more during the 24 months prior to administration of eculizumab.

[0094] Disability can be assessed based on EDSS scores comparing the change from baseline in the two treatment groups. The Kurtzke Expanded Disability Status Scale (EDSS) is a method of quantifying disability in multiple sclerosis. The EDSS replaced the Disability Status Scale previously used for multiple sclerosis (MS). The EDSS quantifies disability in eight functional systems (FS) and allows neurologists to assign functional system scores (FSS) in each of these systems. The functional systems are pyramidal, cerebellar, brainstem, sensory, bowel and bladder, visual, cerebral, and other. EDSS steps 1.0 to 4.5 refer to MS patients who are fully able to walk. EDSS steps 5.0 to 9.5 are defined by walking impairment. Disability will also be assessed based on mRS scores comparing the change from baseline in the two treatment groups. mRS scores are assessed by the attending physician at time points specified in the protocol.

[0095] In certain embodiments, the subject receiving NMOSD treatment has an EDSS score of at least 1.0 during the 24 months prior to the administration of eculizumab. In other embodiments, the EDSS score of the subject receiving NMOSD treatment is at least 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 or higher during the 24 months prior to the administration of eculizumab. In other embodiments, the subject receiving NMOSD treatment has an EDSS score of 1.0 to 7.0 during the 24 months prior to the administration of eculizumab. In certain embodiments, the subject receiving NMOSD treatment has an HAI score of at least 2.0 during the 24 months prior to the administration of eculizumab. In other embodiments, the HAI score of the subject receiving NMOSD treatment is at least 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 or 9.0 during the 24 months prior to the administration of eculizumab. In other embodiments, the subject receiving NMOSD treatment has an HAI score of 0.0 to 8.0 during the 24 months prior to the administration of eculizumab. In certain embodiments, the subject receiving NMOSD treatment has an mRS score of at least 0.0 during the 24 months prior to the administration of eculizumab. In other embodiments, the mRS score of the subject receiving NMOSD treatment is at least 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 or higher during the 24 months prior to the administration of eculizumab. In other embodiments, the subject receiving NMOSD treatment has an mRS score of 0.0 to 2.5 during the 24 months prior to the administration of eculizumab.

[0096] Quality of life (QOL) can be assessed at protocol-specified time points using the patient self-assessment questionnaires EQ-5D and SF-36. Sample questionnaires for EQ-5D are as follows: Figure 5 As shown. EUROQOL (EQ-5D) is a reliable and validated survey of health status in 5 domains: mobility, self-care, usual activities, pain / discomfort, and anxiety / depression, which is completed by the subjects. Each domain has 3 levels: Level 1 (no problems), Level 2 (some problems), and Level 3 (extreme problems). EQ-5D is given on Day 1, Weeks 4, 8, 12, 24, 36, 48, 60, 72, 84, 96, and 104, or ET (Visits 2, 6, 8, 10, 16, 22, 28, 34, 40, 46, 52, and 56, or ET). A clinically meaningful improvement in a patient's EQ-5D is reflected as an increase in the score after 26 weeks of treatment. A sample questionnaire for the SF-36 is shown below. Figure 5 shown.

[0097] For example, walking function can be assessed by the HAI scale. For example, visual acuity can be assessed using the Snellen chart. The severity of relapse can be assessed, for example, using the Optic Spinal Injury Score (OSIS). The OSIS scores are summarized in Table 1.

[0098] According to certain embodiments, the subject given eculizumab shows an increase in the time interval between NMOSD relapses. In certain embodiments, the subject is greater than 6 weeks before relapse. In other embodiments, the period before relapse is greater than 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102 weeks or more. In other embodiments, the period before relapse is greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48 weeks or more. In other embodiments, the period before relapse is greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 years or more. In other embodiments, the period before relapse is 6 to 52 weeks, 6 to 26 weeks, 6 to 10 weeks, 26 to 52 weeks, 1 to 2 years, 1 to 5 years, 5 to 10 years or no relapse occurs in the lifetime of the experimenter. In other embodiments, the period before relapse is greater than 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102 months or more.

[0099] According to certain embodiments, the course of treatment with eculizumab lasts for 108 weeks. According to other embodiments, the course of treatment lasts for 26-52, 26-78, 26-120, 26-130, 26-156, 26-104, 26-130, 26-156, 26-182, 26-208 weeks or longer. In other embodiments, the course of treatment lasts for greater than 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182 weeks. According to other embodiments, the course of treatment continues for greater than 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 years or more. In certain embodiments, the course of treatment continues for the remainder of the subject's life.

[0100] According to certain embodiments, during the treatment process, one or more symptoms or scores associated with NMOSD improve during the treatment process and remain at the improved level throughout the treatment process. For example, EDSS can improve after 26 weeks of treatment with a therapeutic antibody that specifically binds to C5, and then maintain the improved level during the treatment period (for example, it can be 52 weeks of treatment with a therapeutic antibody that specifically binds to C5). An example of a therapeutic antibody that binds to C5 is eculizumab.

[0101] In certain embodiments, the first sign of improvement occurs at week 26 of treatment with a therapeutic antibody that specifically binds C5. According to other embodiments, the first sign of improvement occurs at week 1-26, 26-52, 52-78, 78-104, 104-130, 130-156, 156-182, or 182-208 of treatment with a therapeutic antibody that specifically binds C5. In other embodiments, the first sign of improvement occurs at week 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182.

[0102] According to certain embodiments, during treatment with a binding protein that specifically binds to C5 (e.g., eculizumab), the first sign of improvement is maintained for a certain number of weeks. According to certain embodiments, the number of weeks is at least 26. According to other embodiments, the number of weeks is 1-26, 26-52, 52-78, 78-104, 104-130, 130-156, 156-182, or 182-208. In other embodiments, the number of weeks is at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182. According to certain embodiments, when the first sign of improvement is maintained, it means that the indicator for NMOSD treatment does not fall below the value of the first sign of improvement. The indicator may continue to improve, which would still be defined as maintaining the first sign of improvement.

[0103] In one embodiment, the anti-C5 antibody (e.g., eculizumab) or antigen-binding fragment thereof is administered once on day 1 of the administration cycle, once on day 15 of the administration cycle, and then every eight weeks. In one embodiment, the anti-C5 antibody or antigen-binding fragment thereof is administered every eight weeks for an extended period of up to two years after the administration cycle (e.g., at a dose of 3000 mg, 3300 mg, or 3600 mg).

[0104] In another embodiment, the anti-C5 antibody (e.g., eculizumab) or antigen-binding fragment thereof is administered for one or more administration cycles. In one embodiment, the administration cycle is 26 weeks. In another embodiment, the treatment comprises at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 cycles. In another embodiment, the treatment continues throughout the life of the human patient.

[0105] In another embodiment, a method of treating a human patient with NMOSD is provided, the method comprising administering to the patient an effective amount of an anti-C5 antibody (e.g., eculizumab) or antigen-binding fragment comprising the following: CDR1, CDR2, and CDR3 heavy chain sequences as shown in SEQ ID NOs: 19, 18, and 3, respectively, and CDR1, CDR2, and CDR3 light chain sequences as shown in SEQ ID NOs: 4, 5, and 6, respectively, during an administration cycle, wherein the anti-C5 antibody or antigen-binding fragment thereof is administered as follows: (a) once on Day 1 of the administration cycle at a dose of: 2400 mg for patients weighing ≥40 to <60 kg, 2700 mg for patients weighing ≥60 to <100 kg, or 3000 mg for patients weighing ≥100 kg; and (b) on Day 15 of the administration cycle and every eight weeks thereafter, at a dose of 3000 mg for patients weighing ≥40 to <60 kg, 3300 mg for patients weighing ≥60 to <100 kg, or 3600 mg for patients weighing ≥100 kg.

[0106] In another embodiment, a method of treating a human patient with NMOSD is provided, the method comprising administering to the patient during an administration cycle an effective amount of an anti-C5 antibody (e.g., eculizumab) or antigen-binding fragment comprising: CDR1, CDR2, and CDR3 heavy chain sequences as shown in SEQ ID NOs: 19, 18, and 3, respectively, CDR1, CDR2, and CDR3 light chain sequences as shown in SEQ ID NOs: 4, 5, and 6, respectively, and a variant human Fc constant region that binds to a human neonatal Fc receptor (FcRn), wherein the variant human Fc The CH3 constant region comprises Met-429-Leu and Asn-435-Ser substitutions at residues corresponding to methionine 428 and asparagine 434 (each in EU numbering), wherein the anti-C5 antibody (e.g., eculizumab) or antigen-binding fragment thereof is administered as follows: (a) once on Day 1 of an administration cycle at a dose of 2400 mg for patients weighing ≥40 to <60 kg, 2700 mg for patients weighing ≥60 to <100 kg, or 3000 mg for patients weighing ≥100 kg; and (b) on Day 15 of an administration cycle and every eight weeks thereafter at a dose of 3000 mg for patients weighing ≥40 to <60 kg, 3300 mg for patients weighing ≥60 to <100 kg, or 3600 mg for patients weighing ≥100 kg.

[0107] In another embodiment, an anti-C5 antibody (e.g., eculizumab) or an antigen-binding fragment thereof is administered to patients weighing ≥40 to <60 kg: (a) once on day 1 of the administration cycle at a dose of 2400 mg; and (b) on day 15 of the administration cycle and every eight weeks thereafter at a dose of 3000 mg.

[0108] In another embodiment, an anti-C5 antibody (e.g., eculizumab) or an antigen-binding fragment thereof is administered to patients weighing ≥60 to <100 kg: (a) once on day 1 of the administration cycle at a dose of 2700 mg; and (b) on day 15 of the administration cycle and every eight weeks thereafter at a dose of 3300 mg.

[0109] In another embodiment, an anti-C5 antibody (e.g., eculizumab) or an antigen-binding fragment thereof is administered to patients weighing ≥100 kg: (a) once on day 1 of the administration cycle at a dose of 3000 mg; and (b) on day 15 of the administration cycle and every eight weeks thereafter at a dose of 3600 mg.

[0110] In another embodiment, the patient is switched from receiving one C5 inhibitor to a different C5 inhibitor during treatment. Different anti-C5 antibodies can be administered during different treatment periods. In one embodiment, for example, a method of treating a human patient with a complement-related disorder (e.g., NMOSD, e.g., NMO) being treated with eculizumab is provided, the method comprising discontinuing treatment with eculizumab and switching the patient to treatment with an alternative complement inhibitor (e.g., eculizumab). In another embodiment, a method of treating a human patient with a complement-related disorder being treated with eculizumab is provided, the method comprising discontinuing treatment with eculizumab and switching the patient to treatment with an alternative complement inhibitor.

[0111] Exemplary alternative complement inhibitors include, but are not limited to, antibodies or antigen-binding fragments thereof, small molecules, polypeptides, polypeptide analogs, peptide mimetics, siRNAs, and aptamers. In one embodiment, the alternative complement inhibitor inhibits one or more of complement components C1, C2, C3, C4, C5, C6, C7, C8, C9, factor D, factor B, properdin, MBL, MASP-1, MASP-2, or biologically active fragments thereof. In another embodiment, the alternative complement inhibitor inhibits one or both of the generation of anaphylactic toxic activity associated with C5a and / or the assembly of the membrane attack complex associated with C5b. In another embodiment, the alternative complement inhibitor is selected from the group consisting of CR1, LEX-CR1, MCP, DAF, CD59, factor H, cobra venom factor, FUT-175, compstatin, and K76 COOH.

[0112] In another embodiment, a method of treating a human patient with a complement-associated disorder being treated with eculizumab is provided, the method comprising discontinuing treatment with eculizumab and switching the patient to treatment with an alternative anti-C5 antibody. In another embodiment, a method of treating a human patient with a complement-associated disorder being treated with eculizumab is provided, the method comprising discontinuing treatment with eculizumab and switching the patient to treatment with an alternative anti-C5 antibody.

[0113] Exemplary alternative anti-C5 antibodies include, but are not limited to, (i) eculizumab, (ii) an antibody or antigen-binding fragment thereof comprising a heavy chain CDR1, CDR2, and CDR3 domain comprising SEQ ID NOs: 21, 22, and 23, respectively, and a light chain CDR1, CDR2, and CDR3 domain comprising SEQ ID NOs: 24, 25, and 26, respectively, (iii) an antibody or antigen-binding fragment thereof comprising a heavy chain variable region comprising SEQ ID NO: 27 and a light chain variable region comprising SEQ ID NO: 28, (iv) an antibody or antigen-binding fragment thereof comprising a heavy chain CDR1, CDR2, and CDR3 domain comprising SEQ ID NOs: 29, 30, and 31, respectively, and a light chain CDR1, CDR2, and CDR3 domain comprising SEQ ID NOs: 32, 33, and 34, respectively, (v) an antibody or antigen-binding fragment thereof comprising a heavy chain variable region comprising SEQ ID NO: 35 and a light chain variable region comprising SEQ ID NO: NO:36, (vi) comprising the following antibodies or antigen-binding fragments thereof: heavy chain CDR1, CDR2 and CDR3 domains comprising SEQ ID NOs:37, 38 and 39, respectively, and light chain CDR1, CDR2 and CDR3 domains comprising SEQ ID NOs:40, 41 and 42, respectively, (vii) comprising the following antibodies or antigen-binding fragments thereof: a heavy chain variable region comprising SEQ ID NO:43 and a light chain variable region comprising SEQ ID NO:44, and (viii) comprising the following antibodies or antigen-binding fragments thereof: a heavy chain comprising SEQ ID NO:45 and a light chain comprising SEQ ID NO:46.

[0114] In another embodiment, the patient is treated with eculizumab and then switched to treatment with 7086 antibody, 8110 antibody, 305LO5 antibody, SKY59 antibody, H4H12166PP antibody or eculizumab. In another embodiment, the patient is switched from an anti-C5 antibody (e.g., eculizumab, 7086 antibody, 8110 antibody, 305LO5 antibody, SKY59 antibody or H4H12166PP antibody) to another anti-C5 antibody (e.g., eculizumab) during treatment. In a particular embodiment, the patient is switched from eculizumab to eculizumab during treatment.

[0115] In another aspect, the treatment regimen is sufficient to maintain a specific serum trough concentration of an anti-C5 antibody or antigen-binding fragment thereof. In one embodiment, for example, the treatment maintains a serum trough concentration of an anti-C5 antibody or antigen-binding fragment thereof of 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 200, 205 , 210, 215, 220, 225, 230, 240, 245, 250, 255, 260, 265, 270, 280, 290, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395 or 400 μg / mL or more. In one embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 100 μg / mL or more. In another embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 150 μg / mL or more. In another embodiment, the treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 200 μg / mL or more. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 250 μg / mL or greater. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of 300 μg / mL or greater. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of between 100 μg / mL and 200 μg / mL. In another embodiment, treatment maintains a serum trough concentration of an anti-C5 antibody, or antigen-binding fragment thereof, of about 175 μg / mL.

[0116] In another embodiment, to achieve an effective response, to maintain at least 50 μg, 55 μg, 60 μg, 65 μg, 70 μg, 75 μg, 80 μg, 85 μg, 90 μg, 95 μg, 100 μg, 105 μg, 110 μg, 115 μg, 120 μg, 125 μg, 130 μg, 135 μg, 140 μg, 145 μg, 150 μg, 155 μg, 160 μg, 170 μg, 175 μg, 180 μg, 185 μg, 190 μg, 200 μg, 210 μg, 215 μg, 220 μg, 225 μg, 230 μg, 235 μg, 240 μg, 245 μg, 250 μg, 255 μg, 260 μg, 270 μg, 280 μg, 290 μg, 300 μg, 310 μg, 310 μg, 310 μg, 310 μg, 310 μg In one embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains 50 μg to 250 μg of antibody per milliliter of patient blood. In another embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains 100 μg to 200 μg of antibody per milliliter of patient blood. In another embodiment, the anti-C5 antibody is administered to a patient in an amount and frequency that maintains about 175 μg of antibody per milliliter of patient blood.

[0117] In one embodiment, the anti-C5 antibody is administered (or for administration) according to a specific clinical dosing regimen (eg, at a specific dose and / or according to a specific dosing regimen).

[0118] In another embodiment, the dose of the anti-C5 antibody is based on the patient's weight.In some embodiments, 10 mg, 20 mg, 25 mg, 50 mg, 75 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg, 300 mg, 325 mg, 350 mg, 375 mg, 400 mg, 425 mg, 450 mg, 475 mg, 500 mg, 525 mg, 550 mg, 575 mg, 600 mg, 625 mg, 650 mg, 675 mg, 700 mg, 725 mg, 750 mg, 775 mg, 800 mg, 825 mg, 850 mg, 875 mg, 900 mg, 925 mg, 950 mg, 975 mg , 1000mg, 1100mg, 1200mg, 1300mg, 1400mg, 1500mg, 1600mg, 1700mg, 1800mg, 1900mg, 2000mg, 2100mg, 2200mg, 2300mg, 2400mg, 2500mg, 2600mg, 2700m g, 2800mg, 2900mg, 3000mg, 3100mg, 3200mg, 3300mg, 3400mg, 3500mg, 3600mg, 3700mg, 3800mg, 3900mg, 4000mg, 4100mg, 4200mg, 4300mg, 4400mg, 4500 mg, 4600mg, 4700mg, 4800mg, 4900mg, 5000mg, 5100mg, 5200mg, 5300mg, 5400mg, 5500mg, 5600mg, 5700mg, 5800mg, 5900mg, 6000mg, 6100mg, 6200mg, 630 0mg, 6400mg, 6500mg, 6600mg, 6700mg, 6800mg, 6900mg, 7000mg, 7100mg, 7200mg, 7300mg, 7400mg, 7500mg, 7600mg, 7700mg, 7800mg, 7900mg, 8000mg, 81 10400 mg, 10500 mg, 10600 mg, 10700 mg, 10800 mg, 10900 mg, or 11000 mg of an anti-C5 antibody or antigen-binding fragment thereof is administered to a patient weighing ≥40 to <60 kg.

[0119] In another embodiment, 10 mg, 20 mg, 25 mg, 50 mg, 75 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg, 300 mg, 325 mg, 350 mg, 375 mg, 400 mg, 425 mg, 450 mg, 475 mg, 500 mg, 525 mg, 550 mg, 575 mg, 600 mg, 625 mg, 650 mg, 675 mg, 700 mg, 725 mg, 750 mg, 775 mg, 800 mg, 825 mg, 850 mg, 875 mg, 900 mg, 925 mg, 950 mg, 975 mg , 1000mg, 1100mg, 1200mg, 1300mg, 1400mg, 1500mg, 1600mg, 1700mg, 1800mg, 1900mg, 2000mg, 2100mg, 2200mg, 2300mg, 2400mg, 2500mg, 2600mg, 2700m g, 2800mg, 2900mg, 3000mg, 3100mg, 3200mg, 3300mg, 3400mg, 3500mg, 3600mg, 3700mg, 3800mg, 3900mg, 4000mg, 4100mg, 4200mg, 4300mg, 4400mg, 4500 mg, 4600mg, 4700mg, 4800mg, 4900mg, 5000mg, 5100mg, 5200mg, 5300mg, 5400mg, 5500mg, 5600mg, 5700mg, 5800mg, 5900mg, 6000mg, 6100mg, 6200mg, 630 0mg, 6400mg, 6500mg, 6600mg, 6700mg, 6800mg, 6900mg, 7000mg, 7100mg, 7200mg, 7300mg, 7400mg, 7500mg, 7600mg, 7700mg, 7800mg, 7900mg, 8000mg, 81 10400 mg, 10500 mg, 10600 mg, 10700 mg, 10800 mg, 10900 mg, or 11000 mg of an anti-C5 antibody or antigen-binding fragment thereof is administered to a patient weighing ≥60 to <100 kg.

[0120] In another embodiment, 10 mg, 20 mg, 25 mg, 50 mg, 75 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg, 300 mg, 325 mg, 350 mg, 375 mg, 400 mg, 425 mg, 450 mg, 475 mg, 500 mg, 525 mg, 550 mg, 575 mg, 600 mg, 625 mg, 650 mg, 675 mg, 700 mg, 725 mg, 750 mg, 775 mg, 800 mg, 825 mg, 850 mg, 875 mg, 900 mg, 925 mg, 950 mg, 965 mg, 75mg, 1000mg, 1100mg, 1200mg, 1300mg, 1400mg, 1500mg, 1600mg, 1700mg, 1800mg, 1900mg, 2000mg, 2100mg, 2200mg, 2300mg, 2400mg, 2500mg, 2600mg , 2700mg, 2800mg, 2900mg, 3000mg, 3100mg, 3200mg, 3300mg, 3400mg, 3500mg, 3600mg, 3700mg, 3800mg, 3900mg, 4000mg, 4100mg, 4200mg, 4300mg, 440 0mg, 4500mg, 4600mg, 4700mg, 4800mg, 4900mg, 5000mg, 5100mg, 5200mg, 5300mg, 5400mg, 5500mg, 5600mg, 5700mg, 5800mg, 5900mg, 6000mg, 6100mg, 6200mg, 6300mg, 6400mg, 6500mg, 6600mg, 6700mg, 6800mg, 6900mg, 7000mg, 7100mg, 7200mg, 7300mg, 7400mg, 7500mg, 7600mg, 7700mg, 7800mg, 7900 10400 mg, 10500 mg, 10600 mg, 10700 mg, 10800 mg, 10900 mg, or 11000 mg is administered to patients weighing ≥ 100 kg.In certain embodiments, dosage regimens are adjusted to provide the optimum desired response (eg, an effective response).

[0121] In another embodiment, the anti-C5 antibody is administered at a dose of milligrams per kilogram (mg / kg). For example, in one embodiment, the anti-C5 antibody or antigen-binding fragment thereof is administered at a dose of 0.1 mg / kg, 0.25 mg / kg, 0.5 mg / kg, 0.75 mg / kg, 1.0 mg / kg, 1.25 mg / kg, 1.50 mg / kg, 1.75 mg / kg, 2.0 mg / kg, 2.25 mg / kg, 2.50 mg / kg, 2.75 mg / kg, 3.0 mg / kg, 3.25 mg / kg, 3.50 mg / kg, 3.75 mg / kg, 4.0 mg / kg, 4.25 mg / kg, 4.50 mg / kg, 4.75 mg / kg, 5.0 mg / kg, 5.25 mg / kg, g / kg, 5.50mg / kg, 5.75mg / kg, 6.0mg / kg, 6.25mg / kg, 6.50mg / kg, 6.75mg / kg, 7.0mg / kg, 7.25mg / kg, 7.50mg / kg, 7.75mg / kg, 8.0mg / kg, 8.25mg / k g, 8.50mg / kg, 8.75mg / kg, 9.0mg / kg, 9.25mg / kg, 9.50mg / kg, 9.75mg / kg, 10.0mg / kg, 11.25mg / kg, 11.50mg / kg, 11.75mg / kg, 12.0mg / kg, 12.25m g / kg, 12.50mg / kg, 12.75mg / kg, 13.0mg / kg, 13.25mg / kg, 13.50mg / kg, 13.75mg / kg, 14.0mg / kg, 14.25mg / kg, 14.50mg / kg, 14.75mg / kg, 15.0mg / kg, 15.25mg / kg, 15.50mg / kg, 15.75mg / kg, 16.0mg / kg, 16.25mg / kg, 16.50mg / kg, 16.75mg / kg, 17.0mg / kg, 17.25mg / kg, 17.50mg / kg, 17.75mg / k g, 18.0mg / kg, 18.25mg / kg, 18.50mg / kg, 18.75mg / kg, 19.0mg / kg, 19.25mg / kg, 19.50mg / kg, 19.75mg / kg, 20.0mg / kg, 20.25mg / kg, 20.50mg / kg, 20.75mg / kg, 21.0mg / kg, 21.25mg / kg, 21.50mg / kg, 21.75mg / kg, 22.0mg / kg, 22.25mg / kg, 22.50mg / kg, 22.75mg / kg, 23.0mg / kg, 23.25mg / kg, 23.50mg / kg, 23.75mg / kg, 24.0mg / kg, 24.25mg / kg, 24.50mg / kg, 24.75mg / kg or 25.0mg / kg. .

[0122] In one embodiment, the anti-C5 antibody is administered once a week, twice a week, three times a week, four times a week, five times a week, six times a week, or every day. In another embodiment, the anti-C5 antibody is administered twice a day. In another embodiment, the anti-C5 antibody is administered once every two weeks, once every three weeks, once every four weeks, once every five weeks, once every six weeks, once every seven weeks, once every eight weeks, once every nine weeks, once every ten weeks, once every eleven weeks, or once every twelve weeks. In another embodiment, the anti-C5 antibody is administered as a loading dose on day 1, followed by a different maintenance dose on day 15 and every eight weeks thereafter.

[0123] In another embodiment, to obtain an effective response, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a minimum free C5 concentration. In one embodiment, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a free C5 concentration of 0.2 μg / mL, 0.3 μg / mL, 0.4 μg / mL, 0.5 μg / mL or less. In another embodiment, an anti-C5 antibody is administered to a patient in an amount and frequency to maintain a free C5 concentration of 0.309 to 0.5 μg / mL or less.

[0124] In some embodiments, patients treated according to the methods described herein have been vaccinated against meningococcal infection within three years prior to or at the time of starting the study drug. In one embodiment, patients who begin treatment less than two weeks after receiving a meningococcal vaccine receive appropriate prophylactic antibiotic therapy until two weeks after vaccination. In another embodiment, patients treated according to the methods described herein are vaccinated against meningococcal serotypes A, C, Y, W135, and / or B.

[0125] In light of the present disclosure, conventional molecular biology, microbiology, and recombinant DNA techniques within the skill of the art may be employed. Such techniques are fully described in the literature. See, e.g., Sambrook, Fritsch & Maniatis, Molecular Cloning: A Laboratory Manual, 2nd ed. (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York (herein "Sambrook et al., 1989"); DNA Cloning: A Practical Approach, Vols. I and II (D. N. Glover, ed. 1985); Oligonucleotide Synthesis (M. J. Gait, ed. 1984); Nucleic Acid Hybridization [B. D. Hames & S. J. Higgins, eds. (1985)]; Transcription And Translation [B. D. Hames & S. J. Higgins, eds. (1984)]; Animal Cell Culture [Animal Cell Culture [R. I. Freshney, ed. (1986)]; Immobilized Cells And Enzymes [Immobilized cells and enzymes] [IRL Press, (1986)]; B. Perbal, A Practical Guide To Molecular Cloning [Practical Guide to Molecular Cloning] (1984); FM Ausubel et al. (eds.), Current Protocols in Molecular Biology [Current Protocols in Molecular Biology], John Wiley & Sons, Inc. (1994). Each of these references is incorporated herein by reference in its entirety.

[0126] Unless otherwise indicated, the sequence identity / similarity values ​​provided herein refer to the values ​​obtained using the BLAST 2.0 suite of programs using default parameters (Altschul, S. et al., Nucleic Acids Res., 25:3389-402, 1997), which is incorporated herein by reference in its entirety).

[0127] As used herein, "sequence identity" or "identity" in the context of two polypeptide sequences includes reference to residues in the two sequences that are identical when aligned for maximum correspondence over a specified comparison window. When the percentage of sequence identity is used for proteins, it is recognized that non-identical residue positions are usually different due to conservative amino acid substitutions, in which amino acid residues are replaced by other amino acid residues with similar chemical properties (e.g., charge or hydrophobicity), and therefore the functional properties of the molecule are not changed. When the sequences are different in conservative substitutions, the percentage of sequence identity can be adjusted upward to correct the conservative nature of the substitution. Sequences that differ by such conservative substitutions are referred to as having "sequence similarity" or "similarity". The means for making such adjustments are known to those skilled in the art (typically, this involves scoring conservative substitutions as partial rather than complete mismatches, thereby improving percentage sequence identity.). Therefore, for example, when the same amino acid score is 1, and the score of non-conservative substitutions is zero, the score of conservative substitutions is between zero and 1. The score for conservative substitutions is calculated, for example, according to the algorithm of Meyers, E. and Miller, W. (Compute. Appl. Biosci. [Computer Application to Biological Sciences], 4: 11-7, 1988), for example, as implemented in the program PC / GENE (Intelligenetics, Mountain View, Calif., USA). Each of these references is incorporated herein by reference in its entirety.

[0128] As used herein, "sequence identity percentage" means a value determined by comparing two optimally aligned sequences over a comparison window, wherein the polynucleotide sequence portion in the comparison window may include additions or deletions (i.e., gaps) compared to a reference sequence (which does not include additions or deletions) for optimal alignment of the two sequences. The percentage can be calculated by the following method: the number of positions at which the same nucleic acid base or amino acid residue appears in the two sequences is determined to produce a matching position number, the matching position number is divided by the total number of positions in the comparison window, and the result is multiplied by 100, thereby obtaining a sequence identity percentage.

[0129] In the context of polynucleotide sequences, the term "substantial identity" or "substantially identical" means that the polynucleotide comprises a sequence having between 50-100% sequence identity (e.g., at least 50% sequence identity, at least 60% sequence identity, at least 70%, at least 80%, at least 90%, or at least 95%) compared to a reference sequence using one of the described alignment programs using standard parameters. The skilled artisan will recognize that these values ​​can be appropriately adjusted to determine the corresponding identities of the proteins encoded by the two nucleotide sequences by taking into account codon degeneracy, amino acid similarity, reading frame position, and the like. Substantial identity of amino acid sequences for these purposes generally means 55-100%, e.g., at least 55%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% sequence identity.

[0130] Examples Example 1. Efficacy and safety of eculizumab in the treatment of adult patients with neuromyelitis optica spectrum disorder (NMOSD) 1. Study design 1.1. Overall design This is a Phase 3, external placebo-controlled, open-label, multicenter study designed to evaluate the efficacy and safety of eculizumab in adult patients with NMOSD. Approximately 55 eligible adult patients with NMOSD from North America, Europe, Asia Pacific, and Japan participated in the study.

[0131] This study has 4 phases: screening phase, main treatment phase, long-term extension phase, and safety follow-up phase ( Figure 1 ). During the Screening Period, patients were screened for eligibility for up to 6 weeks. The Primary Treatment Period ended and the Long-Term Extension Period began when all patients completed the Week 26 visit or terminated early and then completed their End of Primary Treatment Period (EOPT) visit. All patients continued to receive eculizumab in the Long-Term Extension Period for up to 2 years or until eculizumab was approved and / or available (based on country-specific regulations), whichever comes first. Based on the estimated enrollment rate of patients with NMOSD, the total treatment duration for each patient was up to 4 years. Patients were followed for 8 weeks after the last dose of study drug or early discontinuation (ED).

[0132] When eligible patients join the study, they receive an intravenous infusion of eculizumab. Each patient's eculizumab dose is based on body weight. The dosing regimen consists of a loading dose followed by a maintenance dose administered every 8 weeks (q8w). The maintenance dose should start 2 weeks after the loading dose.

[0133] For each patient, the total duration of study participation was up to 4 years and 14 weeks, including a screening period (up to 6 weeks), a main treatment period (26 weeks to 2 years), a long-term extension period (up to 2 years), and a safety follow-up period (8 weeks).

[0134] 1.2. Scientific Principles of Research Design This study was designed to provide data that fully characterize the benefit-risk profile of eculizumab in patients with NMOSD, using placebo data from another study of eculizumab in NMOSD as an external control.

[0135] The single-group design, utilizing the placebo arm in Study NCT01892345 (conducted from 2014 to 2018) as an external placebo control, allowed for a robust evaluation of eculizumab as a treatment option for NMOSD. Whenever possible, consistency with Study NCT01892345 was maintained to ensure valid comparisons, including inclusion of similar patient populations, allowing for concomitant medications, adjudication procedures, and endpoints.

[0136] 1.2.1. Rationale for the selection of endpoints 1.2.1.1. Efficacy endpoints In NMOSD, measurable biological aspects include relapses and disability. Disability in NMOSD is a direct consequence of relapses, supporting the relevance of measuring relapses as an efficacy endpoint.

[0137] In this study, the occurrence of relapse was evaluated using the primary endpoint TFR and the secondary endpoint ARR. The time to first relapse provides useful information about the efficacy of eculizumab. Since the effectiveness of a treatment can be based on delaying and / or reducing the occurrence of relapses, TFR is an appropriate efficacy endpoint for prospectively designed studies in NMOSD. The external placebo group of study NCT01892345 was used as an appropriate control group because the primary endpoint of that trial was also TFR and the adjudication process and relapse definition would remain unchanged between the two trials. In addition, the effect of eculizumab on the frequency of relapse was measured using the adjudicated in-trial ARR. 95% confidence intervals will be calculated around the ARR. The objectives and endpoints of this study are summarized in Table 1 below.

[0138] Table 1. Objectives and endpoints.

[0139] A relapse during the study is defined as a relapse that occurs during the study treatment period as determined by the treating physician. All relapses will be adjudicated by a separate adjudication committee.

[0140] 1.2.2. Rationale for duration of primary treatment period In this study, the main treatment period ends when all patients complete the Week 26 visit or terminate early. By then, it is expected that the first enrolled patient will have been treated for approximately 2 years, based on the estimated enrollment rate, and the remaining patients will be treated for 26 weeks to 2 years (inclusive).

[0141] There are several reasons for choosing a 26-week cutoff for the last patient. In previous studies of eculizumab, a key observation could be made at that time: 2 of 3 adjudicated on-trial relapses were observed in the eculizumab group and 12 of 20 adjudicated on-trial relapses were observed in the placebo group. This design ensured that a limited number of patients were censored within the first 26 weeks in the analysis of time to first adjudicated on-trial relapse. It was also recognized that, based on the anticipated enrollment schedule, many patients would have been treated for more than 1 year by the time the last patient completed the Week 26 visit, providing efficacy and safety data over time to allow for robust comparisons with data collected over a similar time frame in the placebo arm of Study NCT01892345.

[0142] 1.2.3. Rationale for the selection of patient populations Complement activation is a major determinant of disease pathogenesis in patients with anti-AQP4-positive NMOSD. Therefore, inhibition of terminal complement activation with eculizumab represents a biologically plausible approach to treat patients with anti-AQP4-positive NMOSD. Study inclusion criteria were carefully selected to reflect a population of adult patients with anti-AQP4-positive NMOSD that is consistent with the population of anti-AQP4-positive NMOSD that may be treated with eculizumab in clinical practice.

[0143] 1.3. Rationale for dosage 1.3.1. Eculizumab The use of complete terminal complement inhibition as a therapeutic strategy for the treatment of patients with NMOSD has been validated by data from the eculizumab clinical program. The dosing regimen of eculizumab is designed to target immediate, complete, and sustained inhibition of terminal complement in patients. The weight-based eculizumab dosing in the previous PNH program was based on PK / PD data from early and late clinical development studies in healthy adult volunteers and PNH patients. The proposed eculizumab dosing regimen (Section 3.1; Section 5.1.6.1) is an approved regimen for patients treated with PNHU1. The regimen for treating patients was included in the United States Prescribing Information (USPI), and the same dosing regimen was also included in the initial Marketing Authorization Application (MAA) in the European Union. Therefore, the same dosing regimen was selected for this study.

[0144] 1.3.2. Supplement dosage Supplemental doses of eculizumab (Section 5.1.6.2) may be administered to patients who received plasma exchange (PE) / plasmapheresis (PP) as acute therapy after relapse in the trial (Section 3.5.1.3). Supplemental doses of eculizumab have been selected based on PK simulations. Consistent with the approved eculizumab label for the treatment of adult and pediatric patients with aHUS, adult patients with generalized myasthenia gravis (gMG), and adult patients with NMOSD, supplemental doses of eculizumab are given in the case of concomitant PP / PE therapy at 50% (rounded to an integer if not 300 mg due to vial configuration).

[0145] 1.4. End of the main treatment period Once all patients complete their Week 26 visit or terminate early, patients will return within 14 days for their primary end-of-treatment period (EOPT) visit: If the EOPT visit coincides with an upcoming scheduled study visit, the patient must complete all assessments for the EOPT visit and may also be administered their scheduled dose of eculizumab.

[0146] If the patient is in the relapse assessment period for their first relapse (defined as first relapse after Day 1), the Week 6 relapse assessment visit is the patient's EOPT visit.

[0147] The end of the primary treatment period was defined as the date on which all patients completed the Week 26 visit or discontinued early and then completed the EOPT visit.

[0148] 1.5. Definition of study end Patients who met any of the following criteria were considered to have completed the study: · The patient completes all phases of the study, including the last visit shown in the activity schedule.

[0149] Patients completed the study early because eculizumab was registered or approved.

[0150] End of study was defined as the last patient in the overall trial ( Figure 2 )’s last visit date.

[0151] 2. Study population Prospective approval of protocol deviations (also known as protocol waivers or exemptions) from recruitment and inclusion criteria is not permitted.

[0152] 2.1. Inclusion criteria Participants were eligible for inclusion in the study only if all criteria in 2.2.1 to 2.2.5 applied.

[0153] 2.1.1. Age Patients had to be 18 years of age or older when signing the informed consent form.

[0154] 2.1.2. Patient types and disease characteristics The included patients and disease characteristics are as follows: Anti-AQP4 Ab positivity and NMOSD diagnosis as defined by the 2015 International Consensus Diagnostic Criteria (Wingerchuk, D. et al., Neurology, 85:177-89, 2015). A positive anti-AQP4 Ab test in the medical history may be acceptable if the test is performed using an acceptable, validated cell-based assay from an accredited laboratory. In this case, the medical history test results and related information need to be reviewed and approved by the sponsor's medical monitor prior to starting study treatment.

[0155] At least 1 episode or relapse in the last 12 months before the screening period (Note: patients with a single lifetime episode were considered to meet this inclusion criterion if the episode occurred in the past 12 months.) Expanded Disability Status Scale (EDSS) score ≤ 7 Patients entering the trial receiving supportive IST (e.g., corticosteroids, azathioprine [AZA], mycophenolate mofetil [MMF], methotrexate [MTX], and tacrolimus [TAC]) in combination or as monotherapy to prevent relapse must be on a stable dosing regimen of adequate duration prior to screening, with no planned dose changes during the study, as follows: If patients entering the study were receiving AZA, they must have been using AZA for at least 6 months prior to screening and had been on a stable dose for more than 2 months.

[0156] b. If patients entering the study were receiving other IST (e.g., MMF, MTX, or TAC), they must have been using IST for at least 3 weeks before screening and had been on a stable dose for more than 4 months.

[0157] c. If patients entering the study are receiving oral corticosteroids, they must be on a stable dose for more than 4 weeks prior to screening.

[0158] d. If the patient is receiving one or more oral corticosteroids, with or without one or more other ISTs, at trial entry, the daily corticosteroid dose prior to screening must not exceed 20 mg / day of prednisone (or equivalent).

[0159] · Vaccination against Neisseria meningitidis within 3 years before or at the time of starting eculizumab. Patients starting study drug therapy less than 2 weeks after receiving meningococcal vaccination must receive appropriate prophylactic antibiotics until 2 weeks after vaccination.

[0160] 2.1.3. Weight Body weight not less than 40kg.

[0161] 2.1.4. Gender Contraception for males or females should comply with local regulations regarding contraception methods for participation in clinical studies. Male patients must agree to use contraception during treatment and for at least eight months after the last dose of study drug and not to donate sperm during this period.

[0162] Female patients are eligible if they are not pregnant, not breastfeeding, and meet at least one of the following criteria: Not a woman of childbearing potential (WOCBP), or · Be WOCBP and use a highly effective or acceptable method of contraception during treatment and for at least eight months after the last dose of study drug.

[0163] o The investigator will assess the effectiveness of the contraceptive method regarding the first dose of study medication. WOCBP must have a negative highly sensitive pregnancy test (serum pregnancy test) within 24 hours prior to the first dose of study medication. The investigator is responsible for reviewing medical history, menstrual history, and recent sexual activity to reduce the risk of inclusion of women who did not have an early pregnancy detected.

[0164] 2.1.5. Informed consent Be able to sign informed consent, including compliance with the requirements and restrictions outlined in the Informed Consent Form (ICF) and this protocol.

[0165] 2.2. Exclusion criteria If any of the criteria from 2.2.1. to 2.2.4 applied, the patient would be excluded from the study.

[0166] 2.2.1. Medical conditions History of Neisseria meningitidis infection.

[0167] Human immunodeficiency virus (HIV) infection (demonstrated by HIV-1 or HIV-2 antibody titers) History of unexplained infection Active systemic bacterial, viral, or fungal infection within 14 days prior to Day 1 study drug administration Fever of 38°C (100.4°F) or higher within 7 days before the first day of study drug administration Hypersensitivity to murine proteins or one of the excipients of eculizumab Any medical condition that the investigator believes may interfere with the patient's participation in the trial, pose any additional risk to the patient, or confound the patient's assessment.

[0168] 2.2.2. Previous / concomitant therapy Previous or current treatment with complement inhibitors.

[0169] Use of rituximab within 3 months before screening.

[0170] Use of mitoxantrone within 3 months before screening.

[0171] · Use of intravenous immunoglobulin (IVIg) within 3 weeks prior to screening.

[0172] 2.2.3. Prior / concurrent clinical research experience and other exclusions Participation in any other study with an investigational drug or exposure to an investigational drug or device within 30 days of screening or 5 half-lives of the investigational drug, whichever is greater.

[0173] Pregnant, breastfeeding, or planning to become pregnant during the study 2.3. Lifestyle considerations There were no lifestyle restrictions in this study.

[0174] 2.4. Screening failure Screening failures are defined as patients who consented to participate in a clinical study but subsequently did not receive study drug treatment. Individuals who do not meet the inclusion criteria for participation in this study (screening failures) for reasons that are expected to resolve or have resolved may be rescreened based on discussion and consensus between the Investigator and the Medical Monitor. Patients who experience a relapse that meets the protocol definition of a relapse in the trial (Section 5.2.3.2) during the screening period will be considered screening failures. Such patients may be rescreened for inclusion in the trial after receiving treatment for the relapse and when the Investigator and the Medical Monitor believe that the patient is medically stable (Sections 2.1; 2.2). Patients must meet the inclusion criteria at the time of rescreening to enter the study.

[0175] 3. Study Drugs Study drug is defined as any one or more investigational drugs, one or more marketed products, placebo, or one or more medical devices intended to be administered to study patients according to the study protocol.

[0176] 3.1. One or more study drugs administered In this study, patients received open-label eculizumab throughout the treatment period (Table 2; see Section 5.1.6 for study drug dose and administration and SoA for dosing schedule ( Figure 2 ).

[0177] Table 2. Study drugs.

[0178] IMP = investigational medicinal product; IV = intravenous; NIMP = non-investigational medicinal product; q8w = every 8 weeks Details on study medication dosing are provided in Section 5.1.6 3.2. Preparation / Processing / Storage / Accountability Upon arrival of the study drug at the study site, the study drug kit was removed from the shipping container and stored in its original carton under refrigeration at 2°C to 8°C (35°F to 47°F) and protected from light. Eculizumab was not frozen. Study drug was stored in a secure, restricted-access storage area, and the temperature was monitored daily.

[0179] Aseptic technique should be used to prepare the infusion of study drug. Eculizumab was further diluted 1:1 with a compatible diluent. Eculizumab was filtered with a 0.2 micron filter during infusion. In addition, the infusion of study drug followed the following rules: · The investigator or designee verifies that all study medications received maintain appropriate temperature conditions during transportation and that any discrepancies are reported and resolved prior to use of the study medication.

[0180] Only patients enrolled in the study may receive study medication, and only authorized site personnel may provide or administer study medication. All study medications are stored in a secure, environmentally controlled, and monitored (manual or automated) area according to labeled storage conditions, with access limited to study personnel and authorized site personnel.

[0181] The investigator, institution, or medical facility head, as applicable, is responsible for study medication accountability, reconciliation, and record maintenance (e.g., records of receipt, reconciliation, and final disposition).

[0182] Further guidance and information on the final disposal of unused study medication is provided in the Pharmacy Manual.

[0183] 3.3. Measures to reduce bias: randomization and blinding This was a single-group, open-label study. All study patients, site personnel, sponsor personnel, sponsor designees, and all personnel directly involved in the conduct of the trial were unaware of the patients' treatment assignments.

[0184] To minimize potential bias in this open-label study, operational measures were used for efficacy endpoints and adjudication. The trial database was monitored according to prespecified guidelines to confirm that all potential relapses were collected and analyzed. An independent relapse adjudication committee assessed each trial relapse and confirmed whether it met protocol-defined NMOSD relapse criteria (Section 5.2.3.2). In addition, although the EDSS raters were aware that all patients were receiving eculizumab, the EDSS raters were unaware of all trial data when making their assessments.

[0185] 3.4. Study drug compliance Infusion of study medication into patients is under the supervision of the investigator or his / her designee to ensure that patients receive the appropriate dose at the appropriate time points during the study.

[0186] The date and time of each dose administered in the clinic was recorded in the source documentation and documented on the case report form (CRF).

[0187] The dose of study drug and the identity of the study patient were confirmed at the time of administration by study site staff, not the person administering the study drug.

[0188] 3.5. Concomitant therapy Any medications (including over-the-counter or prescription medications, vitamins, minerals, and / or herbal supplements) or vaccines that the patient was receiving at the time of enrollment or received during the study were recorded in the patient’s source documents / medical records and electronic case report form (eCRF) along with the following: Reasons for use Date of application, including start and end dates Dosage information, including dose and frequency Any changes in concomitant medications were also recorded in the patient’s source documents / medical records and in the eCRF. Whenever possible, concomitant medications were recorded from the first infusion of eculizumab until the patient discontinued or completed the study.

[0189] Information on the use of IST (including steroids) was collected. Meningococcal vaccination and antibiotics (if applicable) administered to prevent meningococcal infection were also recorded.

[0190] Any concomitant medications deemed necessary for the patient's care or treatment of any AEs during the study, as well as any other medications, except those listed as not permitted in Section 3.5.2, may be given at the investigator's discretion. However, it is the investigator's responsibility to ensure that details of all medications are fully documented in the patient's source files / medical records and in the eCRF.

[0191] If you have any questions about concomitant or prior therapy, please contact the Medical Monitor.

[0192] 3.5.1. Permitted drugs and therapies The following concomitant medications and therapies were permitted for this study.

[0193] 3.5.1.1. Palliative and supportive care Palliative and supportive care for underlying conditions was permitted during the trial.

[0194] 3.5.1.2. Immunosuppressants Supportive immunosuppressive therapy (IST) for the prevention of relapse, either in combination or as monotherapy, was permitted at the investigator's discretion, such as: Corticosteroids Azathioprine (AZA) Mycophenolate mofetil (MMF) Methotrexate (MTX) Tacrolimus (TAC) Cyclosporine Cyclophosphamide If patients were receiving supportive IST prior to the study and continued on stable maintenance therapy during the study, refer to the IST requirements in the Inclusion Criteria (Section 2.1) to ensure that patients were on a stable dose within the limits of the study requirements as described in the Study Criteria (Section 2).

[0195] For each patient, no adjustment in IST dose and no new IST were allowed in the first 106 weeks unless the patient experienced a relapse or safety event and the investigators considered it necessary to change the IST dose or regimen to ensure the patient's safety.

[0196] Any changes in immunosuppressive therapy are documented in the source document and on the Concomitant Medication page of the eCRF.

[0197] 3.5.1.3. Standardized treatment for relapse Treatment of relapse is at the discretion of the attending physician. Based on expert opinion, the following standardized treatment regimen is recommended for confirmed on-trial relapse (Section 5.2.3.2): One gram (1 g) of intravenous methylprednisolone (IVMP) is administered daily for 3-5 days, followed by a taper of oral prednisone.

[0198] If the patient improves, the trial assessments will continue according to the schedule of this protocol.

[0199] If there is no or minimal response to IVMP, PE / PP is permitted at the discretion of the treating neurologist. Five cycles of PE, with each cycle removing 1.0-1.5 volumes of circulating plasma, are recommended for treatment of episodes that do not respond to IVMP.

[0200] o If a patient receives PE / PP due to an on-trial relapse during the treatment period, a supplemental dose of study drug should be administered after each PE / PP as described in Supplemental Doses in Section 5.1.6.2. After receiving the supplemental dose, the patient will continue to follow the protocol-specified dosing schedule in the SoA ( Figure 2 ).

[0201] 3.5.2 Unacceptable drugs and therapies The following medications and therapies were prohibited during the study.

[0202] Mitoxantrone Rituximab or other biologics, such as tocilizumab Immunomodulatory therapies, including interferon beta-1b; interferon beta-1a, glatiramer acetate, natalizumab, alemtuzumab, dimethyl fumarate, teriflunomide, siponimod, and fingolimod.

[0203] IVIg for relapse prevention PE for prevention of recurrence 3.6. Dose Modification Dose modifications were not allowed in this study.

[0204] 3.7. Post-study intervention After the last scheduled dose, patients should not be offered eculizumab ( Figure 2 and 3 All patients were followed for an additional 8 weeks for safety after the last dose of study drug or early discontinuation.

[0205] 4. Discontinuation of study drug and patient discontinuation or withdrawal 4.1. Discontinuation of Study Drug In rare cases, patients may need to permanently discontinue (definitive discontinuation) study drug. If study drug is definitive discontinuation, the patient will remain in the study for follow-up safety assessments. See SoA ( Figure 2 and Figure 3 ) Understand the data to be collected at study drug discontinuation and follow-up and any further assessments that need to be completed.

[0206] Patients were considered to have discontinued study drug if any of the following occurred during the study: Severe hypersensitivity reactions; Severe uncontrolled infection; Use of non-permitted drugs as defined in Section 3.5.2 are pregnant or planning to become pregnant; or The sponsor or investigator considers it necessary for the patient.

[0207] 4.2. Patient Discontinuation / Withdrawal from the Study Every effort should be made to ensure that the patient is willing to comply with study participation before conducting the screening procedure. Study staff should notify the sponsor and their site monitor of all trial withdrawals as soon as possible. The reasons for patient discontinuation are recorded in the source documents and in the eCRF.

[0208] A patient may withdraw from the study at any time at his / her own request or at the investigator's discretion for safety, compliance, or administrative reasons. This is expected to be uncommon.

[0209] In the event of study discontinuation, an early discontinuation visit will be performed, if possible, as indicated in the SoA ( Figure 2 Patients who discontinued prematurely were followed for an additional 8 weeks for safety and any further assessments that warranted completion.

[0210] Patients will then permanently discontinue both study drug and the study.

[0211] If a patient withdraws consent for future disclosure of information, the sponsor may retain and continue to use any data collected prior to the withdrawal of consent.

[0212] 4.3. Loss to follow-up If the patient fails to return or is otherwise unable to be seen within the acceptable visit window ( Figure 2 ) for a scheduled visit, site research staff will make reasonable attempts to contact the patient to determine the reason for the missed appointment.

[0213] Patients who fail to return for a scheduled visit will be contacted by the site's research staff to determine the reason for the missed appointment. Because it is critical to obtain information on any patient's missed visit to ensure that the missed appointment is not due to an AE or potential recurrence, every effort will be made to perform protocol-specified safety follow-up procedures.

[0214] In special circumstances where a patient cannot or does not come to the study site for an examination, the patient will be directed to see his or her local neurologist or internist. In such cases, the attending physician or designee will contact the local neurologist or internist, if possible, to obtain as much information as possible about the patient's medical and neurological status and provide clinical guidance when needed. The study site will obtain relevant medical records from the local internist's examination for documentation and enter relevant data on the Relapse Assessment Visit Form or AE Form, as appropriate.

[0215] If a patient failed to return for scheduled visits multiple times and could not be contacted by the study site, he or she was considered lost to follow-up.

[0216] If a patient fails to return to the clinic for a required study visit, the following actions will be taken: ·The site attempted to contact patients and reschedule missed visits as quickly as possible and counseled patients on the importance of maintaining the assigned visit schedule and determined whether the patient wished and / or should continue on the study.

[0217] Before a patient is considered lost to follow-up, the investigator or designee makes every effort to re-establish contact with the patient (three phone calls when possible and, if necessary, certified mail to the patient's last known mailing address or local equivalent). These contact attempts are documented in the patient's medical record.

[0218] If the patient continues to be unreachable, he / she will be considered lost to follow-up.

[0219] 5. Research Evaluation and Procedures The study procedures and their timing are summarized in the SoA ( Figure 2 ). No protocol waivers or exemptions are permitted. Safety concerns are discussed promptly with the sponsor upon occurrence or awareness to determine whether the patient should receive the study drug. Adherence to study design requirements, including those specified in the SoA, is essential to the conduct of the study. All screening assessments are completed and reviewed to confirm that potential patients meet all eligibility criteria. The investigator maintains a screening log to record the details of all screened patients and confirm eligibility or document the reason for screening failure, as applicable. Procedures performed as part of the patient's routine clinical management (e.g., blood counts) and obtained prior to signing the ICF may be used for screening or baseline purposes, provided that the procedures meet the criteria specified in the protocol and are performed within the timeframe defined in the SoA.

[0220] 5.1. General evaluation and procedures 5.1.1. Informed consent Before any study procedures were performed, the investigator or a qualified designee obtained signed and dated informed consent from each patient. Every effort was made to ensure that the patient was willing to comply with trial participation before screening procedures were performed.

[0221] 5.1.2. Attending physician The attending physician was the principal investigator (PI) / subinvestigator for the study and was responsible for overall patient management, including patient eligibility assessment, oversight of study drug administration, documentation and treatment of AEs, and monitoring of safety assessments.

[0222] At the time of relapse, the treating physician will perform a complete neurological examination and determine if the patient's signs and symptoms meet the criteria for an on-trial relapse (Section 5.2.3.2). They may also treat the patient's relapse according to the recommended treatment regimen for the on-trial relapse. Ultimately, the treatment and treatment options for the on-trial relapse and any changes in IST following an on-trial relapse are at the discretion of the treating physician.

[0223] 5.1.3. Medical history and history of NMOSD Researchers reviewed patients' medical histories and diagnoses and recorded the following at the screening visit: Date of NMOSD diagnosis and previous magnetic resonance imaging (MRI) that aided in the diagnosis. Confirmation of the diagnosis of NMOSD as defined by the International Panel for NMO Diagnosis (IPND) criteria (section 7.1), including that the patient met specific criteria for the diagnosis. Only patients who were anti-AQP4Ab positive and otherwise met the 2015 IPND criteria were eligible to participate.

[0224] All available information regarding relapses that occurred prior to screening and that meet the protocol definition of a historical relapse (Section 5.2.3.1) will be recorded, including oNumber of relapses (onset date) o Clinical presentation of each relapse (eg, optic neuritis [ON], transverse myelitis [TM], brainstem, area postrema, or other) o Acute and maintenance treatment and dosing regimens, and o Any disability measure, such as EDSS score.

[0225] 5.1.4. Vaccine and antibiotic prevention As with any terminal complement inhibitor, use of eculizumab increases a patient's susceptibility to meningococcal infection (Neisseria meningitidis). To reduce the risk of meningococcal infection, all patients received a meningococcal vaccination within 3 years prior to starting study drug.

[0226] Patients who start study drug therapy less than 2 weeks after receiving meningococcal vaccine will receive appropriate prophylactic antibiotic therapy until 2 weeks after vaccination.

[0227] Vaccinate or revaccinate patients according to current national vaccination guidelines or local practices for vaccination with complement inhibitors (e.g., eculizumab, eculizumab).

[0228] Vaccines against serotypes A, C, Y, W135, and B are recommended when available to protect against common pathogenic meningococcal serotypes.

[0229] Vaccination may not be sufficient to prevent meningococcal infection. Consider appropriate use of antibacterial agents according to official guidelines and local practice.

[0230] Monitor all patients for early signs of meningococcal infection and promptly evaluate if infection is suspected and treat with appropriate antibiotics if necessary.

[0231] 5.1.5. Inclusion / Exclusion Criteria All inclusion (Section 2.1) and exclusion (Section 2.2) criteria are reviewed by the Investigator or a qualified designee to ensure that the patient is eligible to participate in the study. Both the Investigator and the Sponsor must approve the patient's eligibility prior to enrollment.

[0232] 5.1.6. Study Drug Administration This section describes the dosing schedule for the study drug. Figure 2 ), study drug administration was performed after completion of all other tests and procedures (excluding post-dose blood sampling for PK and free C5).

[0233] 5.1.6.1. Eculizumab Patients received a weight-based loading dose of eculizumab by intravenous infusion on day 1, followed by a weight-based maintenance dose on day 15 (Table 3), and then every 8 weeks (q8w). The total treatment duration was up to 4 years, when all patients completed the 2-year long-term extension period or until eculizumab was approved and / or available (according to country-specific regulations), whichever came first.

[0234] Depending on when relapse occurs, scheduled eculizumab dosing visits may or may not overlap with relapse assessment visits and / or follow-up relapse assessment visits. During the relapse assessment period, eculizumab dosing visits continue as planned.

[0235] Table 3. Eculizumab doses based on body weight.

[0236] The dosing regimen will be based on the last recorded study visit body weight. If study medication is prepared the evening before the visit, the body weight from the most recent study visit should be used.

[0237] 5.1.6.2. Supplemental dosage During the study, PE / PP is permitted for on-trial recurrence at the discretion of the treating physician (Section 3.5.1.3). Figure 2 ), the supplemental dose will be administered within 4 hours of completion of PE / PP and will be based on the most recently administered dose of eculizumab (Table 4). Figure 2 ), no supplemental dose of eculizumab will be administered. Patients will receive their regular dose of eculizumab 60-120 minutes after completion of PE / PP (Section 5.1.6.1) (See Section 5.6.2 for PK and free C5 sample collection during relapses in the trial.).

[0238] After receiving the supplemental dose, patients will continue study drug infusion according to the protocol-specified dosing schedule ( Figure 2 ).

[0239] Table 4. Supplemental doses of eculizumab administered at unscheduled visits after treatment of recurrent PE / PP on trial.

[0240] 5.2. Efficacy evaluation Neurological examination Throughout the study, the attending physician (Section 5.1.2) (who is the study investigator and has received appropriate training as a clinical assessor), preferably the same attending physician, will review the clinical assessor at scheduled visits ( Figure 2 ) for a complete general neurological examination.

[0241] A complete general neurologic examination includes assessment of the following systems: mental status, fundus examination, cranial nerves, deep tendon reflexes, plantar responses, strength / power, sensation, coordination, and gait / balance.

[0242] 5.2.2. NMO symptom card and assessment Before receiving the first dose of study drug at Visit Day 1, patients were given an NMO symptom card that listed potential signs and symptoms of an NMOSD relapse and contact information.

[0243] At each visit throughout the study, study staff ensured that patients had their NMO symptom cards. The attending physician reviewed and evaluated the patients for any signs or symptoms suggesting a relapse.

[0244] 5.2.3. Relapse 5.2.3.1. Historical recurrence A historical relapse was a relapse that occurred before the screening visit, including the first NMOSD episode. For this protocol, a historical relapse was defined as a new onset of neurologic symptoms or a worsening of existing neurologic symptoms, with objective changes on neurological examination (clinical findings or MRI findings or both) lasting for more than 24 hours. An event occurring within the 30-day interval was considered a relapse.

[0245] 5.2.3.2. Relapse during the trial 5.2.3.2.1 Definition of Relapse in Trial An on-trial relapse is an acute attack that occurs during the study treatment period. For this protocol, an on-trial relapse is defined as a new onset of neurological symptoms or a worsening of existing neurological symptoms, with objective changes in neurological examination (clinical signs) lasting for more than 24 hours as confirmed by the attending physician (Section 5.1.2). Signs and symptoms must be attributed to NMOSD, i.e., not caused by identifiable causes such as infection, excessive exercise, or excessive ambient temperature. Isolated changes without associated clinical findings on MRI or other imaging studies are not considered on-trial relapses.

[0246] 5.2.3.2.2 Evaluation of Relapse During the Trial In-trial relapses were monitored throughout the study. The investigator or qualified designee carefully examined the patients for signs and symptoms of potential relapse at each visit.

[0247] Patients were educated about potential signs and symptoms of NMOSD relapse and instructed to contact the study site at the first sign or symptom of a potential relapse.

[0248] Patients should be evaluated within 24 hours (and no later than 48 hours) of notification of signs or symptoms suggestive of a potential relapse.

[0249] Assessment of relapse in the trial included the following: Complete a neurological examination to determine if clinical signs, symptoms, and findings meet the trial definition of relapse · Assess the severity of relapse according to OSIS (section 5.2.8; Figure 8 The OSIS visual acuity (VA) subscale score was used to classify the severity of ON. The OSIS motor subscale score and sensory subscale score were used to classify the severity of TM.

[0250] Assessment of neurological function system according to Kurtzke's Functional System Score (FSS) and disability grade based on EDSS score (Section 5.2.4).

[0251] · Assessment of walking function using the HAI (Section 5.2.7).

[0252] · Eye examination including VA, confrontation visual field (VF), and color vision (Section 5.2.9).

[0253] · Perform MRI + / - gadolinium and / or ocular coherence tomography (OCT) to evaluate for potential recurrence as determined by the investigator (Section 5.2.10).

[0254] Additional testing and follow-up evaluations as specified in the SoA ( Figure 3 ) 5.2.3.2.3 Treatment of relapse during trial At suspected relapse, a complete neurological examination was performed by the attending physician (Section 5.1.2) to determine if the patient was experiencing an on-trial relapse. If the event was determined by the attending physician to be an on-trial relapse, treatment of the relapse and any changes in IST following relapse were at the discretion of the investigator.

[0255] Section 3.5.1 provides recommended standardized treatments for on-trial relapses.

[0256] See Section 5.1.6 for administration of supplemental doses of eculizumab during relapse on trial.

[0257] 5.2.3.2.4 Follow-up of Relapse During the Trial Perform relapse assessment visits according to the schedule specified in the SoA to monitor the relapse process ( Figure 3 Additional (unplanned) follow-up relapse assessment visits beyond the designated time points were performed at the discretion of the investigator or subinvestigator.

[0258] Following relapse, patients could remain on the trial if the patient and the investigator / subinvestigator decided that continuing to receive study drug was appropriate.

[0259] All reports of possible relapses and actions taken for possible relapses were documented in the patient's source files and recorded in the eCRF.

[0260] 5.2.3.2.5 Determination of relapse during the trial On-trial relapses were independently reviewed by a Relapse Adjudication Committee (RAC), which consisted of physicians with special expertise in NMOSD who independently reviewed all on-trial relapses. The committee decided by majority vote whether each reported on-trial relapse met the objective criteria for an on-trial relapse. A separate section documents all adjudication criteria and procedures for this study.

[0261] 5.2.4 Expanded Disability Status Scale (EDSS) The 10-point Kurtzke EDSS (section 7.2) is widely used and accepted as an effective tool for quantifying disability and monitoring changes in disability over time (Kurtzke, J., Neurology, 33: 1444-52, 1983). The EDSS scale ranges from 0 to 10.0 in increments of 0.5 units.

[0262] 5.2.4.1. Expanded Disability Status Scale The total EDSS score is determined by 2 factors: gait and FSS (Section 5.2.4.2), as follows: EDSS scores below 4.0 are determined by FSS only.

[0263] People with EDSS scores of 4.0 and above are likely to have some degree of gait impairment.

[0264] EDSS scores between 4.0 and 9.5 were determined by gait ability and FSS.

[0265] 5.2.4.2. Functional system score Functional systems (FS) represent networks of neuronal systems responsible for specific tasks / functions. The EDSS assigns a severity score to a patient's clinical status using the FSS, which assesses functional impairment in the following 8 FSs (Section 7.2). The FSs for functional systems 1 to 7 are scored on a scale of 0 (low level of problems) to 5 or 6 (high level of problems) to best reflect the level of disability observed clinically. The "other" category consists of any other neurological findings attributed to NMOSD and is dichotomous, with 0 indicating absence and 1 indicating any presence.

[0266] 5.2.4.3. EDSS and FSS raters EDSS and FSS are administered in person by trained raters. EDSS raters perform a complete Kurtzke neurological examination and record FSS and EDSS scores. The following rules apply: EDSS raters should not be the PI and should not be directly involved in the management of trial patients. If possible, EDSS raters should be physicians. If a non-physician EDSS rater (e.g., a professional nurse) is used, the rater must be approved by the sponsor before conducting the assessment.

[0267] • EDSS raters remained blinded to all other study data and all other patient clinical data.

[0268] • The blinded EDSS rater was responsible for performing EDSS assessments throughout the study period, including at relapses. Whenever possible, the same blinded rater performed the EDSS for each patient at the visit specified in the SoA.

[0269] • The EDSS rater performed the complete Kurtzke neurological examination, as described in Section 7.2, and recorded the Functional System Score (FSS) and EDSS score (Kurtzke, 1983).

[0270] For specific requirements on EDSS rater qualifications, please refer to the training materials provided by the sponsor. For the roles and responsibilities of investigators and EDSS raters, please refer to Table 5.

[0271] Table 5. Roles and responsibilities of investigators / attending physicians and EDSS raters.

[0272] EDSS = Expanded Disability Status Scale; EQ-5D = European Quality of Life-5 Dimensions; FSS = Functional System Score; HAI = Hauser Walking Index; OSIS = Optic Spinal Cord Injury Score; SF-36 = Short-Form Health Survey; VA = visual acuity.

[0273] a May be performed by the researcher or a designated person.

[0274] EuroQoL 5 Dimensions (EQ-5D) European Quality of Life (EQ-5D) Figure 5 ) is a self-assessed standardized tool to measure health-related QoL, which has been used for a wide range of health conditions, including NMOSD (Schrag, A. et al., J. Neurol. Neurosurg. Psychiatry, 69:67-73, 2000). EQ-5D consists of 2 pages: the EQ-5D description system and the EQ visual analog scale (EQ VAS) ( Figure 5 ). The EQ-5D was administered at each visit prior to other study procedures.

[0275] 5.2.5.1.EQ-5D descriptive system The descriptive system is a 5-component scale that includes mobility, self-care, usual activities, pain / discomfort, and anxiety / depression. Each level is rated on a scale that describes the extent of the problem in that domain.

[0276] 5.2.5.2.EQ Visual Analogue Scale The EQ-5D VAS is an overall health status scale in which patients select a number between 0-100 to describe their health status, where 100 is “the best health you can imagine” and 0 is “the worst health you can imagine”.

[0277] This information can be used as a quantitative measure of health outcomes as judged by individual respondents. Previous research published by members of the EuroQol group showed preliminary evidence of the feasibility, reliability and validity of the tool.

[0278] 5.2.6. Short Form Health Survey (SF-36) The SF-36 is a 36-item self-report measure of health-related quality of life (Stewart, AL, & Ware, JE, Jr. (eds.). (1992). Measuring functioning and well-being: The medical outcomes study approach. Durham, NC: Duke University Press; Ware, JE, Jr. (1988). How to score the revised MOS short-form health scales. Boston: Institute for the Improvement of Medical Care and Health, New England Medical Center.). It contains eight subscales measuring different domains of health-related quality of life: physical functioning, role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. The two summary total scores are the physical component summary and the mental component summary. There is no single summary score for the SF-36.

[0279] 5.2.7.Hauser Walk Index (HAI) The HAI is a rating scale developed to assess mobility by evaluating the time and degree of assistance required to walk 25 feet. Figure 7 The attending physician or appropriately trained designee performs HAI testing during protocol-specified visits ( Figure 3 ), which is briefly described below.

[0280] Patients are asked to walk a marked 25-foot route as quickly and safely as possible.

[0281] The examiner records the time and type of assistance needed (eg, cane, walker, crutches). The rating scale also categorizes patients who are unable to walk.

[0282] Although the patients' walking was timed, this time was not used directly, but was used in combination with other factors to rate the patients on an 11-point ordinal scale (Bethoux, F. and Bennett, S., Int. J. Care, 13:4-14, 2011). This assessment was performed on all patients in this study.

[0283] 5.2.8. Optic spinal injury score (OSIS) OSIS is a scoring system used to assess the severity of relapse ( Figure 8 ). The OSIS VA subscale score was used to classify the severity of ON. The OSIS motor subscale score and sensory subscale score were used to classify the severity of TM. The OSIS was assessed by the treating physician at baseline and at relapse during the trial. Further instructions on the OSIS assessment of relapse during the trial are provided in Section 5.2.3.2.

[0284] 5.2.9. Eye examination 5.2.9.1. Adversarial Vision Oppositional VF is assessed by the attending physician. Knowledge of baseline ophthalmologic status is critical for these assessments so that changes in examination can be used to assess previous or ongoing ON. Central scotoma is common in patients experiencing ON; however, visual field loss can present in a wide spectrum of patterns (Keltner, J. et al., Am. J. Ophthalmol., 128:543-53, 1999).

[0285] 5.2.9.2. Color Vision Color vision is assessed by the attending physician or any appropriately trained designee using Ishihara Plates. Color vision loss can be a marker of ON and is therefore an important assessment tool in NMOSD.

[0286] 5.2.9.3. Vision Visual acuity is usually affected by ON and progresses over a period of hours to days. The Landolt C ring chart is used to assess VA.

[0287] The Landolt C consists of a ring with a gap, so it looks similar to the letter C. The gap can be in different positions (usually left, right, bottom, top, and 45° in between), and the tester's task is to determine which side the gap is on. The size of the C and its gap are reduced until the patient has a specified error rate. The minimum perceptible angle of the gap serves as a measure of visual acuity.

[0288] The attending physician or appropriately trained designee performs VA testing during protocol-specified visits ( Figure 3 ), as described below.

[0289] The test is performed at a standard distance, usually 6 meters or 20 feet.

[0290] The Landolt chart is usually recorded as visual acuity versus distance (6 meters or 20 feet), so for normal VA it would be recorded as 20 / 20 or 6 / 6. Sometimes this is entered as the denominator of the Landolt fraction (US) or as a decimal (outside the US).

[0291] The test is always performed with optimal correction as needed (e.g., with glasses), and each eye is tested independently.

[0292] 5.2.10 Magnetic resonance imaging and ocular coherence tomography Baseline MRI (contrast is optional) and OCT of the brain, cervical spine, and thoracic spine were performed. Exceptions may be made if approved by the Alexion Medical Monitor (e.g., based on recent historical results available for the study).

[0293] At relapse, MRI (contrast was optional) and / or OCT of the brain, cervical spine, and / or thoracic spine were performed at the investigator's discretion to evaluate for potential recurrence when deemed clinically relevant.

[0294] Follow-up assessments should be performed immediately after an on-trial relapse if the investigator decides that these are needed (Section 5.2.3).

[0295] 5.3. Safety assessment The SoA provides the planned time points for all security assessments ( Figure 2 and Figure 3 ).

[0296] 5.3.1. Physical examination A complete physical examination includes, at a minimum, an assessment of the following organs / body systems: skin, head, ears, eyes, nose, throat, neck, lymph nodes, pulse, chest, heart, abdomen, extremities, and musculoskeletal. A targeted physical examination includes, at a minimum, relevant examinations of body systems based on the investigator's judgment and the patient's symptoms.

[0297] The investigators pay particular attention to clinical signs associated with pre-existing serious illness. For consistency, every effort will be made to have the physical examination performed by the same qualified research staff at each study visit. Additional physical examinations may be performed at the discretion of the investigators during the study as medically indicated.

[0298] 5.3.2. Height and weight Weight is in pounds or kg. Height is in inches or centimeters.

[0299] 5.3.3. Vital signs Assess oral temperature (°C or °F), pulse rate, respiratory rate (RR), and systolic and diastolic blood pressure (BP) (mm Hg). Measurement of BP and pulse is assessed at a seated position using fully automated equipment. Manual techniques are used only when automated equipment is not available. Allow the patient to rest for at least 5 minutes in a quiet environment without distractions (e.g., television, mobile phones) before measuring BP and pulse. Ideally, the same arm is used for each patient.

[0300] 5.3.4. Electrocardiogram In SoA( Figure 2 and 3 A single 12-lead ECG is performed using an ECG machine during the protocol-specified visit to obtain measurements of heart rate and PR, QRS, QT, and QTc intervals. The patient lies supine for approximately 5-10 minutes prior to ECG acquisition and remains supine but awake during ECG acquisition. The investigator or a qualified designee is responsible for reviewing the ECG to assess whether the ECG is within normal limits and to determine the clinical significance of the results. These assessments are documented in the source files and the eCRF.

[0301] 5.3.5. Patient Safety Card Prior to the first dose of study drug, a patient safety card was provided for study patients to carry at all times. The card was provided to increase patient awareness of the risk of infection, particularly meningococcal infection, and to facilitate rapid recognition and disclosure of any potential signs or symptoms of infection experienced by study patients during the study and to inform patients of the steps they must take if they develop signs or symptoms of infection.

[0302] At each visit throughout the study period, study staff ensured that patients had a patient safety card.

[0303] 5.3.6. Prior and Concomitant Medical Review It is important for the investigator or qualified designee to review each medication the patient is taking prior to starting the study and at each visit.

[0304] 5.3.6.1. Previous medications Prior medications and / or vaccines (including vitamins, herbal preparations, and those discussed in Exclusion Criteria Section 2.2) and procedures (any therapeutic intervention, such as surgery / biopsy or physical therapy) taken or experienced by the patient within 30 days prior to the start of screening or during the screening period prior to the first dose of eculizumab, as well as any meningococcal vaccines administered within the past 3 years, will be recorded in the patient's eCRF. In addition, all medications or therapies (including steroids) used for relapse prevention or acute treatment of NMOSD prior to the first dose of eculizumab will be collected.

[0305] 5.3.6.2. Concomitant medications The use of concomitant medications and non-drug therapies was assessed during the study (Section 6.5). At each visit, patients were asked if they had any new medications or non-drug therapies or changes in concomitant medications and non-drug therapies since the last visit. Concomitant medications and non-drug therapies were recorded in source documents and in the patient's eCRF.

[0306] 5.3.7. Clinical safety laboratory evaluation The investigator reviews the laboratory reports, documents this review, and records any clinically relevant changes that occur during the study in the AE section of the CRF. Laboratory reports are filed with the source documents. Clinically significant abnormal laboratory findings are those that are not related to the underlying disease unless, in the investigator's judgment, are more severe than expected for the patient.

[0307] Laboratory tests for all values ​​considered clinically significant abnormal were repeated during study participation or within 8 weeks after the last dose of study drug until such values ​​returned to normal or baseline or were no longer considered clinically significant by the investigator or Medical Monitor. If such values ​​did not return to normal / baseline within a time deemed reasonable by the investigator, the etiology was determined and the sponsor was notified. All protocol-required laboratory evaluations as defined in Appendix 2 were performed in accordance with the laboratory manual and SoA. If a laboratory value resulting from a non-protocol-specified laboratory evaluation performed at the institution's local laboratory required a change in patient management or was considered clinically significant by the investigator (e.g., or AE or dose modification), the result was recorded in the CRF.

[0308] 5.3.8. Monitoring for Risk of Suicidal Ideation and Behavior Because the study drug is being evaluated for neurological indications, patients treated with the study drug should be appropriately monitored and observed closely for suicidal ideation or behavior or any other unusual behavioral changes, particularly at the beginning and end of the study drug course, or at dose changes.

[0309] During this study, baseline assessments of suicidal ideation and behavior as well as emergence during the intervention were monitored using the Columbia-Suicide Severity Rating Scale (C-SSRS).

[0310] Two types of C-SSRS assessments were performed during the study: baseline C-SSRS ( Fig.10 ) and C-SSRS since last visit ( Fig.11 ). The C-SSRS is performed by the treating physician or appropriately trained designee at visits designated in the SoA to ensure that patients who are experiencing suicidal thoughts or behaviors are appropriately identified and adequately managed or referred for further evaluation. Additional C-SSRS assessments are permitted as needed.

[0311] 5.4. Adverse Events and Serious Adverse Events Adverse events are reported to the investigator by the patient (or, where appropriate, by the caregiver, surrogate, or legally authorized representative of the patient).

[0312] The Investigator and any qualified designees are responsible for detecting, recording, and documenting events that meet the definition of an AE or SAE and remain responsible for follow-up of AEs that are serious, considered to be related to study drug or study procedures, or that lead to patient discontinuation of study drug (see Section 4).

[0313] For this trial, information regarding recurrences that did not meet SAE criteria was recorded in source documents and in the eCRF as part of the recurrence assessment visit and not as an AE report.

[0314] 5.4.1. Time period and frequency of collecting adverse event and serious adverse event information All AEs and SAEs were collected from the last visit signed on the ICF until the time point specified in the SoA ( Figure 2 and 3 ).

[0315] like Figure 2 and Figure 3 All SAEs will be recorded and reported to the Sponsor or designee immediately and in no event more than 24 hours as indicated in the FDA's FDA Regulations. The Investigator will submit any updated SAE data to the Sponsor within 24 hours of becoming aware of it.

[0316] The investigator has no obligation to actively look for AEs or SAEs after study participation ends. However, if the investigator learns of any SAE, including death, at any time after a patient leaves the study and he / she believes the event is reasonably related to the study drug or study participation, the investigator must promptly notify the sponsor.

[0317] 5.4.2. Methods for detecting AE and SAE Care should be taken not to introduce bias when detecting AEs and / or SAEs. Open-ended and non-leading verbal questioning of patients is the preferred method for inquiring about the occurrence of AEs.

[0318] 5.4.3. Follow-up of AEs and SAEs The investigator is required to proactively follow up each patient at subsequent visits / contacts following the initial AE / SAE report. Follow up all SAEs and AEs of special interest (AESIs; as defined in Section 5.4.6) until resolved, stabilized, events are otherwise explained, or the patient is lost to follow-up (as defined in Section 4.3). Make every effort to perform protocol-specified safety follow-up procedures.

[0319] 5.4.4.SAE Regulatory Reporting Requirements It is essential that investigators notify sponsors of SAEs promptly in order to fulfill their legal obligations and ethical responsibilities for patient safety and the safety of investigational drugs in clinical studies.

[0320] Sponsors have a legal responsibility to inform local and other regulatory agencies about the safety of investigational drugs in clinical studies. Sponsors comply with country-specific regulatory requirements related to reporting safety to regulatory agencies, Institutional Review Boards (IRBs) / Independent Ethics Committees (IECs), and investigators.

[0321] Report suspected unexpected serious adverse reactions (SUSAR) according to local regulatory requirements and sponsor policy and forward to the investigator when necessary.

[0322] Investigators who receive an Investigator Safety Report describing a SAE or other specific safety information (e.g., a SAE summary or listing) from the sponsor review the safety report and then file it with the Investigator's Manual and notify the IRB / IEC, if appropriate according to local requirements.

[0323] 5.4.5. Pregnancy All WOCBP were tested for pregnancy at the time points specified in the protocol in the SoA ( Figure 2 and 3 Pregnancy testing (urine or serum) may also be performed at any time during the study at the discretion of the investigator.

[0324] A negative pregnancy test is required for WOCBP prior to study drug administration. The following rules apply: • Collect detailed information on all pregnancies in female patients and female partners of male patients (if applicable) from the start of study drug until termination of pregnancy.

[0325] If a pregnancy is reported, the investigator will notify the sponsor within 24 hours of learning of the pregnancy.

[0326] Abnormal pregnancy outcomes (e.g., spontaneous abortion, fetal death, stillbirth, congenital anomaly, ectopic pregnancy) were considered SAEs. Pregnancy alone was not considered an AE If a patient becomes pregnant, the study drug will be discontinued immediately and the sponsor will be notified. Each pregnancy will be followed to term and the sponsor will be notified of the outcome.

[0327] 5.4.6. Adverse events of special concern Meningococcal infection was collected as an adverse event of special interest (AESI).

[0328] 5.5. Overdose treatment For this study, any dose of study drug greater than that specified in the protocol was considered an overdose.

[0329] Unexpected overdoses without any association with laboratory abnormalities or clinical symptoms were not considered AEs. Investigators reported overdoses to the sponsor within 24 hours, regardless of whether they were associated with an AE.

[0330] The sponsor does not recommend specific treatment for overdose.

[0331] In the event of an overdose, researchers will: Contact the Medical Monitor immediately.

[0332] Monitor patients closely for any AEs / SAEs.

[0333] If requested by the Medical Monitor (determined on a case-by-case basis), obtain plasma samples for PK analysis.

[0334] Record the number of overdoses and the time of the overdose on the CRF.

[0335] Decisions regarding dose interruptions will be made by the investigator based on the patient's clinical assessment in consultation with the Medical Monitor.

[0336] 5.6. Pharmacokinetics and pharmacodynamics At the time specified in the SoA ( Figure 2 and 3 ) Blood samples for determination of serum drug concentrations and PD assessments were collected before and after study drug administration. Cerebrospinal fluid (CSF) samples for PK and PD assessments were collected at protocol-specified time points ( Figure 2 and 3 ) is optional and can only be obtained from patients who consent to CSF ​​collection. The sponsor will provide instructions for biospecimen collection and processing. The actual date and time (24-hour clock) of each sample will be recorded on the eCRF and the central laboratory reporting form. Additional information regarding sample collection, including blood volume requirements, is provided in the laboratory manual.

[0337] 5.6.1 Sample Collection During the Study Period Baseline (B) and trough (T) PK and PD blood samples will be collected pre-dose, within 90 minutes prior to administration of study drug at the visit specified in the SoA (Section 1.3). Pre-dose blood samples may be drawn prior to dose administration through venous access created for dose infusion. Post-dose (P) PK and PD blood samples will be collected post-dose, within 120 minutes after completion of study drug infusion. Post-dose blood samples will be drawn from the patient's opposite, non-infused arm. Blood samples for non-dose visits may be collected at any time. In the case of unscheduled visits, PK and PD blood samples will be collected as soon as possible.

[0338] 5.6.2 Sample Collection During the Study Period Blood samples for PK and PD analyses will be collected at any time during the scheduled relapse assessment visits. However, if the relapse-related blood sample collection schedule is consistent with routine sample collection as specified in the SoA ( Figure 2 and 3 ), the instructions for periodic PK and PD sample collection during the study should be followed (Section 5.6.1).

[0339] During the on-study relapse period, if patients receive supplemental doses of PE / PP and eculizumab at the relapse evaluation visit, 3 blood samples for PK and PD should be collected at the following intervals: 1. About 5 to 90 minutes before PE / PP 2. After PE / PP and before study drug infusion 3. At least 60 minutes after the completion of study drug infusion If a patient receives PE / PP at any visit other than the relapse assessment visit, blood samples for PK and PD will be collected immediately before and after each PE / PP session. Post-dose samples will also be collected (e.g., 1 hour after completion of the supplemental study drug infusion).

[0340] 5.7. Genetics There were no prespecified genetic analyses in this study.

[0341] 5.8. Biomarker studies 5.8.1. Exploratory biomarker studies Blood samples for biomarker studies will be collected from all patients at the time points specified in the SoA ( Figure 2 and 3 ): CSF samples are optional samples for biomarker studies and can only be collected from patients who consent to the collection of CSF samples. Biomarkers will be measured and include, but are not limited to, assessment of the following: AQP4-Ab at protocol-specified time points (Section 1.3 SoA), including during the Relapse Assessment Period (see Section 5.2.3.2 for further details).

[0342] Complement products Neuroinflammatory markers, such as interleukin 6 (IL-6) Nerve injury markers, such as neurofilament light chain (NfL) 5.8.2. Future biomarker research DNA and RNA sample collection is optional. DNA and RNA blood samples can only be collected from consenting patients. Future DNA and RNA testing on these samples will include but is not limited to specific candidate gene / whole genome analysis.

[0343] The remaining samples from the pharmacokinetic, pharmacodynamic, immunogenicity and biomarker testing will be stored for future biomarker studies. Analysis of biomarker variants thought to play a role in NMOSD activity / progression or treatment response to eculizumab can be performed. These samples can also be used to develop methods, assays, prognostics and / or companion diagnostics related to the study drug target, disease process, pathways associated with the disease state and / or mechanism of action of the study drug.

[0344] Following the last study visit of the last patient, samples may be stored at a facility selected by the sponsor for a maximum period, consistent with local regulations, to enable future analysis.

[0345] 5.9 Immunogenicity Assessment According to SoA( Figure 2 and Figure 3 ) Anti-drug antibodies (ADA) to eculizumab were assessed in serum samples collected from all patients pre-dose (5-90 minutes before the start of study drug infusion).

[0346] In addition, serum samples should be collected at the last visit from patients who discontinued study medication or withdrew from the study.

[0347] Serum samples will be screened for antibodies that bind to eculizumab and the titers of confirmed positive samples will be reported. Additional analyses may be performed to verify the stability of the antibodies to eculizumab and / or to further characterize the immunogenicity of eculizumab.

[0348] Detection and characterization of antibodies to eculizumab will be performed by the sponsor or under the sponsor's supervision using validated assays. If deemed necessary, samples may be further characterized to determine the titer and presence of neutralizing antibodies. Following the last study visit of the last patient, samples may be stored at a facility selected by the sponsor for a maximum period in accordance with local regulations to enable future analysis of immune responses to eculizumab.

[0349] 5.10. Medical resource utilization and health economics The investigators and study site personnel will collect healthcare resource utilization and health economic data related to medical experiences in the CRF for all patients throughout the study. Protocol-mandated procedures, tests, and experiences are excluded.

[0350] The data collected can be used to conduct exploratory economic analysis and will include: Number of surgeries and other selected procedures (inpatient and outpatient) Length of hospital stay The number and type of diagnostic and therapeutic tests and procedures 6. Statistical considerations Statistical assumptions The time to the first adjudicated in-trial relapse will be assessed with the use of the log-rank test; the null hypothesis is that there is no difference in the survival curves between the eculizumab- and placebo-treated groups. The alternative hypothesis is that there is a difference between the two survival curves and that eculizumab is superior to placebo.

[0351] The imputed ARR will be presented with 95% confidence intervals (CIs) to provide an estimate of the imputed ARR rate for patients treated with eculizumab. Although no formal hypothesis testing will be performed on the imputed ARR, we expect the ARR to be lower for patients treated with eculizumab and that the upper limit of the 95% CI will not exceed 0.25 relapses / patient-years.

[0352] For HAI, the null hypothesis is that the odds of a better outcome are the same between the eculizumab and placebo groups. The alternative hypothesis is that there is a difference in the odds of a better outcome between the treatment groups and that eculizumab is associated with a higher odds of a better outcome.

[0353] For the EQ-5D index and EQ-5D VAS, the null hypothesis would be that there is no difference between the distributions of the eculizumab and placebo groups. The alternative hypothesis is that there is a difference between the distributions of the treatment groups and that eculizumab is superior to placebo.

[0354] For EDSS, the null hypothesis was that the odds of a worse outcome were the same between the eculizumab and placebo groups. The alternative hypothesis was that the odds of a worse outcome differed between the treatment groups and that the odds of a worse outcome were higher in the placebo group.

[0355] 6.2. Sample size determination This is an open-label, external placebo-controlled study evaluating eculizumab in patients with NMOSD, with the primary endpoint being time to first adjudicated trial relapse. The placebo-treated group in Study NCT01892345 will serve as the external control.

[0356] The sample size and power calculation assumptions for this study using the primary endpoint, time to first relapse, were as follows: Log-rank test for comparison of eculizumab with placebo 47 patients in the placebo group ·Efficacy 90% Two-sided 5% significance level 2-10% exit rate The relapse-free rate at 12 months was 92% in the eculizumab group The relapse-free rate at 12 months in the placebo group was 63% Under these assumptions, the maximum sample size of approximately 55 patients in the eculizumab-treated group provided at least 90% power to detect a treatment difference in the time to first unequivocally adjudicated relapse.

[0357] 6.3. Populations used for analysis For analysis purposes, the following groups were defined as shown in Table 6 .

[0358] Table 6. Populations used for analysis.

[0359] 6.4. Statistical Analysis The primary analysis will be performed when all patients have completed the primary treatment period. This analysis will include all efficacy, safety, and PK / PD study data for regulatory submission purposes and will serve as the final analysis of the primary treatment period. The SAP to support the primary analysis will be developed and completed shortly after the end of the protocol. If necessary, a final SAP will be developed before the end of the long-term extension period to describe any additional long-term efficacy and safety analyses. This section summarizes the planned statistical analyses and safety analyses for the primary and secondary efficacy endpoints.

[0360] Summary statistics will be calculated and displayed by treatment group and visit (if applicable). Descriptive statistics for continuous variables will include at least the number of patients, mean, standard deviation, minimum, median, and maximum. For categorical variables, frequencies and percentages will be displayed. Graphical displays will be provided when appropriate. Unless otherwise stated, all statistical analyses will be performed based on a 5% 2-sided type I error. Missing data will not be calculated.

[0361] The analysis will use Software version 9.4 or higher.

[0362] 6.4.1. Efficacy analysis Efficacy analyses will include covariate adjustment methods as needed to take into account potential differences in baseline characteristics between the eculizumab groups and the external placebo control. Detailed information will be provided in SAP.

[0363] 6.4.1.1. Primary endpoint The primary efficacy endpoint is the time to first relapse in the adjudicated trial. If a statistically significant difference (e.g., p value <0.05) is observed between the eculizumab treatment group and the placebo group for the primary endpoint of the time to first relapse in the adjudicated trial, the trial will be considered to have achieved its primary efficacy goal. The comparison of the treatment groups for the primary endpoint will use the log-rank test. Hazard ratios and risk reductions will be summarized from the Cox proportional hazards model. For the estimated proportion of patients without relapse at different time points (e.g., Week 26, Week 50), confidence intervals (95%) will be displayed based on complementary log-log transformation. Kaplan-Meier curves for the two treatment groups will be generated.

[0364] Sensitivity analyses of the primary endpoint will be described in the SAP.

[0365] 6.4.1.2. One or more secondary endpoints 6.4.1.2.1. Determination of In-Test ARR The adjudicated in-trial ARR will be presented, showing descriptively the eculizumab treatment group estimate and the 95% CI from a Poisson regression model, in which the logarithm of the time during the study will be used as the offset variable and the historical ARR will be a covariate in the model. This endpoint will be considered statistically significant if the upper limit of the 95% CI is <= 0.25 relapses / year.

[0366] 6.4.1.2.2. Changes in EuroQoL 5 Dimensions (EQ-5D) Index Score and EQ-5D VASEQ-5D Index Score from baseline to the 6-week post-relapse / end of primary treatment period time point (i.e., for the placebo group: 6 weeks post-relapse for patients who relapse, or end of study (EOS) for patients who do not relapse; for the eculizumab group: EQ-5D Index score at the 6-week post-relapse visit with first observed relapse for patients who relapse and at the end of primary treatment period visit for patients who do not relapse) will be analyzed using nonparametric analysis of covariance (ANCOVA) adjusted for baseline EQ-5D Index score. Baseline was defined as the last available assessment before treatment for all patients, regardless of treatment group.

[0367] Changes in the EQ-5D VAS from baseline to the 6-week post-relapse / EOPT time point will be analyzed as described for changes in the EQ-5D index score using nonparametric ANCOVA adjusted for baseline EQ-5D VAS.

[0368] 6.4.1.2.3. Expanded Disability Status Scale (EDSS) The change in EDSS score from baseline to the 6-week post-relapse / EOPT analysis time point will be calculated as described for the EQ-5D endpoint. For EDSS, this change from baseline will be categorized as a clinically important worsening (no worsening, clinical worsening). This endpoint will be analyzed using a logistic regression model including treatment group and baseline EDSS as covariates. Detailed information will be provided in SAP.

[0369] 6.4.1.2.4.Hauser Walk Index (HAI) The change in HAI score from baseline to the 6-week / EOPT analysis time point after relapse will be calculated as described for the EQ-5D endpoint. For HAI, this change from baseline will be classified as a clinically important change (clinical improvement, stability, clinical deterioration). The 3-level endpoint will be analyzed using a proportional advantage model including treatment group and baseline HAI as covariates. Detailed information will be provided in SAP.

[0370] 6.4.1.2.5. Considering Multiple Comparisons A closed-test procedure will be applied to control type I errors for analyses of the primary and secondary endpoints. If the primary endpoint is statistically significant in favor of eculizumab, secondary endpoints will be evaluated according to the following rank order: 1. Determine the ARR in the trial 2. Clinically important change from baseline in walking function as measured by HAI 3. Change from baseline in EQ-5D index score 4. Change from baseline in EQ-5D VAS score 5. Clinically important deterioration in EDSS score from baseline Hypothesis testing will be performed from the highest level (#1) adjudicated ARR to the lowest level (#5) EDSS score in the trial, and if statistical significance is not achieved at the endpoint (p>=0.05 or upper CI limit of ARR>0.25), the lower level endpoint will not be considered statistically significant. For descriptive purposes, confidence intervals and p values ​​will be presented for all secondary efficacy endpoints regardless of the results of the closed testing procedure.

[0371] 6.4.1.3. One or more tertiary / exploratory endpoints The summary and analysis of tertiary and exploratory endpoints will be described in the SAP.

[0372] 6.4.2. Security Analysis All safety data will be summarized using the safety set.

[0373] 6.4.2.1. Adverse event analysis Analysis and reporting of AEs will be based on treatment-emergent adverse events (TEAEs), defined as AEs with onset at or after the first dose of eculizumab. The incidence of TEAEs will be summarized by system organ class (SOC) and preferred term, with an additional summary showing severity, relationship to study drug, TEAEs leading to study drug discontinuation, and TEAEs leading to death. A summary of TESAEs will also be summarized by SOC and preferred term, with an additional summary showing relationship to study drug. These summaries will be presented by treatment group (eculizumab, placebo).

[0374] 6.4.2.2. Analysis of Clinical Laboratory Parameters, Vital Signs Measurements, and ECG Parameters Laboratory measurements and their changes from baseline, as well as changes from baseline (if applicable), will be summarized for each visit. ECG (including ECG interpretation of heart rate), PR, QRS, QT, and QTc intervals, and vital signs will also be summarized.

[0375] 6.4.2.3. Other safety analyses The number and percentage of patients in each C-SSRS category will be presented, as well as the change from baseline.

[0376] 6.4.3. Demographics and baseline characteristics Patient demographics and baseline characteristics will be summarized by treatment group using the safety set. Summary statistics will be presented. No formal hypothesis testing will be performed.

[0377] 6.4.4. Patient Disposition The number of patients screened, treated, completed the study, discontinued the study, reasons for discontinuation, and the number of patients included in each analysis set will be summarized. Major protocol deviations will be summarized by prespecified deviation category.

[0378] 6.4.5. Medical / surgical history and history of neuromyelitis optica spectrum disorder The medical and surgical history will be summarized by SOC and PT via the Medical Dictionary for Regulatory Activities (MedDRA), version 21.0 or later. The history of NMOSD will also be summarized.

[0379] 6.4.6. Prior and concomitant medications Any medication taken before the first dose of study drug will be considered a prior medication; any medication taken at or after the first dose of study drug will be considered a concomitant medication. Prior and concomitant medications, including IST for relapse prevention and acute relapse treatment, will be summarized for all patients in the safety analysis set. Medications will be coded using the World Health Organization Drug Dictionary (WHODrug; the most recent version available at the time of analysis).

[0380] 6.4.7. Pharmacokinetics, pharmacodynamics and anti-drug antibody analysis Individual serum concentration data from all patients who received at least 1 dose of eculizumab and had evaluable PK data will be used to derive PK parameters for eculizumab.

[0381] A graph of the average serum concentration-time spectrum will be constructed. A graph of the serum concentration-time spectrum of an individual patient can also be provided. The actual dose administration and sampling time will be used for all calculations. Descriptive statistics of the serum concentration data at each sampling time will be calculated where appropriate. It may be considered to use data from this study or to combine data from other studies to assess population PK.

[0382] Pharmacodynamic analyses will be performed in all patients who received at least 1 dose of eculizumab and have evaluable PD data.

[0383] Descriptive statistics will be provided for all eculizumab PD endpoints at each sampling time (Section 1.3). The PD effect of eculizumab will be assessed by evaluating the absolute values ​​and changes in free C5 serum concentrations over time and the percentage change from baseline, as appropriate. Assessments of the PK / PD relationship for eculizumab can be explored using data from this study or in combination with data from other studies.

[0384] To assess immunogenicity, the presence of confirmed positive ADA will be summarized. In addition, after confirmation of ADA positivity, the samples will be assessed for ADA titer and the presence of neutralizing antibodies.

[0385] Interim analysis The primary analysis will be performed when all patients have completed the primary treatment period. This analysis will include all efficacy, safety, and PK / PD study data for regulatory submission purposes and will serve as the final analysis of the primary treatment period. This analysis will not be considered an interim analysis. An interim analysis that includes data collected during the long-term extension period may be performed to support submission requirements.

[0386] 6.6. Data Monitoring Committee (DMC) DMCs were not included in this study.

[0387] 7. Supporting Documents and Operational Notes 7.1. Appendix 1: Diagnostic criteria for neuromyelitis optica spectrum disorders International NMO Diagnostic Expert Group Criteria for NMOSD in the Context of AQP4-IgG (Wingerchuk, D. et al., Neurology, 85:177-89, 2015)—In this study, all 3 of the following criteria had to be met to be diagnosed with NMOSD: 1. At least 1 core clinical feature: oOptic neuritis oAcute myelitis o Area postrema syndrome: Other unexplained episodes of hiccups or nausea and vomiting oAcute brainstem syndrome o Symptomatic narcolepsy or acute diencephalic clinical syndrome with typical diencephalic MRI lesions of NMOSD o Symptomatic brain syndrome with typical brain lesions of NMOSD on MRI 2. Positive test for anti-AQP4 Ab using the best available detection method (cell-based assay required for this study) 3. Excluding alternative diagnoses 7.2. Appendix 2: Expanded Disability Status Scale (EDSS) The Kurtzke EDSS is a method of quantifying disability in multiple sclerosis (MS). The EDSS replaced the Disability Status Scale that was previously used for MS. The EDSS quantifies disability in eight functional systems (FS) and allows neurologists to assign a Functional System Score (FSS) in each of these systems. The FS is: ·cone Cerebellum Brainstem Sensory Bowel and bladder Vision ·brain ·other EDSS steps 1.0 to 4.5 refer to fully ambulatory MS patients; EDSS steps 5.0 to 9.5 are defined by walking impairment, such as Figure 4 shown.

[0388] Table 7. Abbreviations. Sequence Summary

Claims

1. A method for treating neuromyelitis optica spectrum disorder (NMOSD) in a human subject in need thereof, the method comprising administering to the human subject an effective amount of an anti-C5 antibody or an antigen-binding fragment thereof, thereby treating NMOSD in the subject, the anti-C5 antibody or antigen-binding fragment thereof comprising the CDR1, CDR2, and CDR3 heavy chain sequences as shown in SEQ ID NOs: 19, 18, and 3, respectively, and the CDR1, CDR2, and CDR3 light chain sequences as shown in SEQ ID NOs: 4, 5, and 6, respectively, wherein the anti-C5 antibody or antigen-binding fragment thereof comprises an Fc region comprising the amino acid sequence as shown in SEQ ID NO: 13, wherein the amino acid sequence comprises up to four amino acid substitutions in the amino acid sequence as shown in SEQ ID NO: 13, and wherein the amino acid substitutions do not include leucine 307 and serine 313.

2. The method of claim 1, wherein the anti-C5 antibody or antigen-binding fragment thereof comprises a heavy chain variable region described by SEQ ID NO: 12 and a light chain variable region described by SEQ ID NO:

8.

3. The method of claim 1, wherein the anti-C5 antibody or antigen-binding fragment thereof comprises the heavy chain constant region described by SEQ ID NO:

13. 4 . The method of claim 1 , wherein the antibody or antigen-binding fragment thereof comprises a heavy chain polypeptide comprising the amino acid sequence of SEQ ID NO: 14 and a light chain polypeptide comprising the amino acid sequence of SEQ ID NO:

11.

5. The method of claim 1, wherein the anti-C5 antibody or antigen-binding fragment thereof is at a concentration of 0.1 nM ≤ K at pH 7.4 and 25°C. D Affinity dissociation constants (K) in the range of ≤1 nM D ) binds to human C5.

6. The method of claim 1, wherein the anti-C5 antibody or antigen-binding fragment thereof is at pH 6.0 and 25°C with a K D ≥10nM binds to human C5.

7. The method of claim 1, wherein the subject is 18 years of age or older.

8. The method of claim 1, wherein the subject is positive for anti-AQP4 antibodies.

9. The method of claim 1, wherein the subject has had at least one attack or relapse in the past 12 months.

10. The method of claim 1, wherein the subject has an Expanded Disability Status Scale (EDSS) score ≤ 7.

11. The method of claim 1, wherein the anti-C5 antibody is administered in the absence of additional immunosuppressive therapy (IST).

12. The method of claim 1, wherein the anti-C5 antibody is administered together with at least one IST.

13. The method of claim 12, wherein the at least one IST is selected from the group consisting of corticosteroids, azathioprine (AZA), mycophenolate mofetil (MMF), methotrexate (MTX) and tacrolimus (TAC).

14. The method of claim 1, wherein the subject weighs at least 40 kg.

15. The method of claim 1, wherein the therapeutically effective dose is based on the subject's body weight.

16. The method of claim 1, wherein the subject exhibits at least one symptom of NMOSD.

17. The method of claim 1, wherein when the subject's body weight is ≥40 and <60 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 2400 mg on day 1 of the administration cycle; and (b) Administer at a maintenance dose of 3000 mg on day 15 of the administration cycle and every eight weeks thereafter.

18. The method of claim 1, wherein when the subject's body weight is ≥60 and <100 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 2700 mg on day 1 of an administration cycle; and (b) Administer at a maintenance dose of 3300 mg on day 15 of the administration cycle and every eight weeks thereafter.

19. The method of claim 1, wherein when the subject's body weight is ≥ 100 kg, and wherein (a) the anti-C5 antibody is administered at a loading dose of 3000 mg on day 1 of the administration cycle; and (b) Administer at a maintenance dose of 3600 mg on day 15 of the administration cycle and every eight weeks thereafter.

20. The method of any of the preceding claims, wherein the treatment maintains a serum trough concentration of the anti-C5 antibody or antigen-binding fragment thereof at 100 μg / mL or greater during the administration period.

21. The method of any of the preceding claims, wherein the treatment maintains a serum trough concentration of the anti-C5 antibody or antigen-binding fragment thereof at 200 μg / mL or greater during the administration period.

22. The method of any of the preceding claims, wherein the treatment maintains free C5 concentrations at 0.309 μg / mL to 0.5 μg / mL or less.

23. The method of any of the preceding claims, wherein the anti-C5 antibody or antigen-binding fragment thereof is administered at a dose of 3000 mg, 3300 mg or 3600 mg every eight weeks after the administration cycle for up to two years.

24. The method of any of the preceding claims, wherein the anti-C5 antibody or antigen-binding fragment thereof is formulated for intravenous administration.

25. The method of any of the preceding claims, wherein the patient has not been previously treated with a complement inhibitor.

26. The method of any one of claims 17-19, wherein the administration cycle is a total of 26 weeks of treatment.

27. The method of any of the preceding claims, wherein the treatment results in terminal complement inhibition.

28. The method of claim 1, wherein the subject undergoes plasma exchange (PE) / plasmapheresis (PP).

29. The method of claim 28, wherein the subject optionally receives a supplemental dose of eculizumab within 4 hours after completion of PE / PP.

30. The method of claim 29, wherein the supplemental dose is 1200 mg-1800 mg of anti-C5 antibody.

31. The method of claim 1, wherein the human subject experiences a clinically meaningful improvement in one or more clinical markers of NMOSD progression following administration of eculizumab.

32. The method of claim 31, wherein the NMOSD progression clinical marker is selected from the group consisting of: adjudicated in-trial ARR, EDSS score, EQ-5D, SF-36, HAI, and OSIS.

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