International Delphi Consensus on the Management of AQP4-IgG+ NMOSD: Recommendations for Eculizumab, Inebilizumab, and Satralizumab

BACKGROUND AND OBJECTIVES

Neuromyelitis optica spectrum disorder (NMOSD) is a rare debilitating autoimmune disease of the CNS. Three monoclonal antibodies were recently approved as maintenance therapies for aquaporin-4 immunoglobulin G (AQP4-IgG)-seropositive NMOSD (eculizumab, inebilizumab, and satralizumab), prompting the need to consider best practice therapeutic decision-making for this indication. Our objective was to develop validated statements for the management of AQP4-IgG-seropositive NMOSD, through an evidence-based Delphi consensus process, with a focus on recommendations for eculizumab, inebilizumab, and satralizumab.

METHODS

We recruited an international panel of clinical experts in NMOSD and asked them to complete a questionnaire on NMOSD management. Panel members received a summary of evidence identified through a targeted literature review and provided free-text responses to the questionnaire based on both the data provided and their clinical experience. Responses were used to generate draft statements on NMOSD-related themes. Statements were voted on over a maximum of 3 rounds; participation in at least 1 of the first 2 rounds was mandatory. Panel members anonymously provided their level of agreement (6-point Likert scale) on each statement. Statements that failed to reach a predefined consensus threshold (≥67%) were revised based on feedback and then voted on in the next round. Final statements were those that met the consensus threshold (≥67%).

RESULTS

The Delphi panel comprised 24 experts, who completed the Delphi process in November 2021 after 2 voting rounds. In round 1, 23/25 statements reached consensus and were accepted as final. The 2 statements that failed to reach consensus were revised. In round 2, both revised statements reached consensus. Twenty-five statements were agreed in total: 11 on initiation of or switching between eculizumab, inebilizumab, and satralizumab; 3 on monotherapy/combination therapy; 7 on safety and patient population considerations; 3 on biomarkers/patient-reported outcomes; and 1 on research gaps.

DISCUSSION

An established consensus method was used to develop statements relevant to the management of AQP4-IgG-seropositive NMOSD. These international statements will be valuable for informing individualized therapeutic decision-making and could form the basis for standardized practice guidelines.

Immune response to two different dosing schedules of the anthrax vaccine precipitated (AVP) vaccine

A pilot study compared the immune response of regular (0, 3, 6, 32 weeks) and extended (0, 10, 13, 32 weeks) schedules of the UK anthrax vaccine (anthrax vaccine precipitated, AVP). Concentrations of antibodies to protective antigen (PA) were higher (p<0.05) among recipients of the extended (n=7) versus regular schedule (n=6) at week 32, and 2 weeks after the second and third vaccinations. Toxin neutralisation assay levels and anti-lethal factor antibodies followed patterns similar to anti-PA antibodies. Extending the interval between the first two AVP vaccinations may produce a stronger immune response, but persistence of this effect needs further study.

Captopril and hydrochlorthiazide--a safe antihypertensive for use in general practice?

The combination of captopril and hydrochlorthiazide was assessed in 15 hypertensive patients in a general practice setting. The first aim was to determine whether the fall in blood pressure, noted after the first dose of an ACE inhibitor given alone, became unacceptable when the drug was given with a diuretic. The second aim was to assess the impact of the ACE inhibitor on the biochemical abnormalities associated with thiazide diuretic therapy. The drug combination markedly reduced blood pressure but not below 110 systolic after the first dose. In the long-term the treatment significantly lowered blood pressure but did not produce any significant or clinically relevant changes in serum chemistry.

Sodium, potassium, body mass, alcohol and blood pressure in three United Kingdom centres (the INTERSALT study)

Standardised data on blood pressure, 24 h urinary electrolyte excretion, body mass index (BMI) and alcohol intake were collected as part of the INTERSALT study in 598 men and women aged 20-59 years, selected randomly from three population groups in the United Kingdom. For the three centres combined, mean systolic blood pressure was 121.4 mm Hg and diastolic pressure 72.1 mm Hg, urinary sodium excretion 152.1 mmol/24 h, urinary potassium excretion 61.0 mmol/24 h, urinary sodium/potassium ratio 2.64 and BMI 25.2 kg/m2. Prevalence of heavy alcohol drinking in men (greater than or equal to 300 ml/week) was 27.5 per cent. Applying overall INTERSALT regression coefficients to the United Kingdom data suggested that modest changes in average sodium and potassium intakes, together with reductions in the prevalence of obesity and (in men) of heavy alcohol drinking could lead to important reductions in average population blood pressures and the prevalence of hypertension. The potential of this multifactorial approach to blood pressure control was illustrated by stratifying individuals within each of the United Kingdom centres by sodium and potassium excretion, BMI and alcohol intake. The 20 (out of 299) men considered at 'lower risk' for high blood pressure with respect to the above variables had systolic pressure lower by 11 mm Hg (P less than 0.01); for the 27 (out of 299) 'lower risk' women, systolic pressure was lower by 5 mm Hg (P = 0.06). These non-pharmacological approaches towards more favourable blood pressure levels could be accompanied by reductions in mortality from stroke and coronary heart disease.

Cigarette smoking. A risk factor for hemorrhagic and nonhemorrhagic stroke

Cigarette smoking habit was studied in 621 patients with stroke and in 573 control subjects using case control methods. There was an excess of smokers among the stroke group when compared with control subjects. Relative risks of cigarette smokers compared with nonsmokers, after adjustment for the possible confounding variables for subarachnoid hemorrhage, intracerebral hemorrhage, and cerebral infarction, were 4.5, 1.8, and 3.2 for men and 2.5, 1.3, and 2.3 for women, respectively. For all subtypes of stroke combined, the increased relative risk was related to the daily intake of cigarettes, the heaviest smokers having a higher relative risk than that for light smokers. The estimated increase in relative risk among smokers was 1.5 for each 10 cigarettes smoked daily in both men and women. We conclude that cigarette smoke may be an important preventable factor for both hemorrhagic and nonhemorrhagic stroke.

Operative or conservative treatment for trochanteric fractures of the femur. A randomised epidemiological trial in elderly patients

All elderly patients with extracapsular hip fractures seen in hospitals in Newcastle upon Tyne over a 12-month period were studied and followed up for six months. At one of the hospitals, patients were randomised to treatment by AO dynamic hip-screw or by traction. Complications specific to the two treatments were low, and general complications, six-month mortality and prevalence of pain, leg swelling and unhealed sores, showed no difference between the two modes of treatment. Operative treatment gave better anatomical results and a shorter hospital stay, but significantly more of the patients treated by traction showed loss of independence six months after injury.

The complications of surgical treatment of displaced fractures of the olecranon

Forty-eight patients who had undergone internal fixation of a displaced fracture of the olecranon by either a tension band technique (34 patients) or screwing (14 patients) were reviewed. The functional results after at least 2 years were equally good with both methods, but there was a considerably higher rate of separation at the fracture after screwing than after inserting a tension band. The technical quality of the fixation was open to criticism in half the cases in each group, and the implications of this are discussed.

The measurement of skin blood flow in peripheral vascular disease by epicutaneous application of Xenon133

Radioactive xenon133 applied epicutaneously was used to study the skin blood flow below the knee in sixteen normal subjects, in eight patients with peripheral vascular disease not requiring amputation, and in a blind study of twenty-nine patients requiring amputation. Following these twenty-nine amputations, the flow rates were made known and correlated with the rates of healing. When the flow rates were above 1.5 milliliters per minute per 100 grams of tissue (skin), the wounds generally healed. In thirteen other patients, Syme or below-the-knee amputations were performed on the basis of the flow rates, and all of the wounds healed. The test, therefore, is now used routinely prior to amputation for peripheral vascular disease as an adjunct to clinical judgment in the determination of the level of amputation.

Syme's amputation. Follow-up study of weight-bearing in sixty-eight patients

Sixty-eight patients with Syme amputations resulting from industrial injuries were reviewed. The amount of end-weight-bearing was measured with a capacitance transducer. The majority of patients required fitting with a prosthesis designed to relieve end-weight-bearing. The old-fashioned prosthesis with a leather corset was the most effective in achieving reduction of end-weight-bearing.

Effect of prolonged saline-exposure on sodium transport across frog skin

1. Differences in Na transport between skins from Rana temporaria and R. esculenta maintained for up to several weeks in water or 0.7% saline (0.7 g NaCl in 100 ml. H(2)O), with and without daily injections of 4% saline (4 g NaCl in 100 ml. H(2)O), were measured, in vitro.2. In saline-treated skins, the following changes were found:(a) An increased Na content.(b) A consistent decrease in short-circuit current (I(sc)).(c) An increased d.c. resistance, R, the consistency of which varied with the anion content of the Ringer solution.(d) A highly significant fall in Na influx, accounting for the reduced I(sc); a small reduction in Na efflux was not significant, statistically.(e) The Pitressin-induced increment in I(sc) was usually considerably lower compared with that in water-exposed skins; considered relative to the pre-Pitressin values, however, there were no clear differences.(f) By calculation from the changes in resistance (R) caused by replacement of outer Na(2)SO(4) Ringer by K(2)SO(4) Ringer solution,I. E(0), the electromotive force of the active sodium transport system, was moderately, but significantly, reduced,II. R(shunt), the shunt path resistance, was moderately, but significantly, increased, andIII. R(ser), the series path resistance, was considerably, and highly significantly, increased.(g) K influx from outer K(2)SO(4) Ringer solution was reduced.3. Differences between skins from water-exposed and saline-treated frogs persisted, in vitro, despite the occurrence of anionic-dependent acute changes after mounting in Ringer solution.4. There were seasonal changes in I(sc), and in the effects of saline treatment.5. The findings are discussed in terms of decreased permeability of outer barriers to ion-diffusion, and reduced activity of a Na pump.