This is a prospective open-label, uncontrolled, single-blind, pilot clinical trial. The primary objective is to assess the efficacy, safety, feasibility and tolerability of SCIG in patients with worsening MG. Participants with moderate worsening of MG symptoms (MGFA Class II and III) who are considered to be appropriate for immunoglobulin therapy will be screened for the study by the treating neurologist. Patients will be receive 2gm/kg (150gm for a 75kg patient) of 20% SCIG (Hizentra) infused over 4 weeks in a dose escalating manner. Additionally, this study will be assessing the feasibility of employing SCIG as an alternative therapy to IVIG in patients with MG exacerbation. The cost-effectiveness of SCIG versus IVIG will be evaluated, and the impact of SCIG therapy will be assessed from both a health-resource perspective and from a patient perspective.
This is a prospective open-label, uncontrolled, single-blind, pilot clinical trial. The primary objective is to assess the efficacy, safety, feasibility and tolerability of SCIG in patients with worsening MG. Study Rationale and Significance Subcutaneous immunoglobulin (SCIG) is a novel form of immune therapy for neuromuscular diseases and may offer several advantages over intravenous immunoglobulin (IVIG). Although no large-scale studies have been in conducted in MG patients, pilot studies with SCIG in multifocal motor neuropathy indicate that it may be a feasible, effective and safe alternative to IVIG in a condition, which like MG, shows excellent response to IVIG infusion. Patients are able to tolerate it better and have improved quality of life due to added flexibility to the treatment schedule. SCIG is also potentially less expensive than IVIG since the costs associated with inpatient treatment as well as nursing support are saved. SCIG also has the potential to be more effective and durable since the serum levels of immunoglobulin show a more sustained increase compared to IVIG. A drawback associated with SCIG is the small amount of immunoglobulin that can be infused over a short period. As compared to IVIG where the usual dose (2gm/kg for neuromuscular diseases) can be infused over 2 - 5 days, the same dose of SCIG would require 3 - 4 weeks to be administered with the currently available formulations. This may mean a delayed onset of peak-dose effect and SCIG may not be feasible for MG patients who are rapidly worsening or in MG crisis. Nevertheless, SCIG may be an attractive option in a large subpopulation of MG patients who have mild to moderate disease exacerbations or who are on maintenance IVIG therapy provided its efficacy, tolerability and feasibility is determined in this patient population. Methodology Participants with moderate worsening of MG symptoms (MGFA Class II and III) who are considered to be appropriate for immunoglobulin therapy at the MG clinic at the University of Alberta will be screened for the study by the treating neurologist. Patients will be receive 2gm/kg (150gm for a 75kg patient) of 20% SCIG (Hizentra) infused over 4 weeks in a dose escalating manner. Participants will undergo infusions two to four times a week, depending on their tolerance, beginning with a dose of 10 ml per site at four injection sites, increasing by 5 ml per week for a total of 25 ml per site at four injection sites after four weeks. The dose is flexible and will vary based on the patient's tolerance to the medication and the total amount of medication the patient will be receiving based on their body weight. The initial (one or two) doses will be infused within the medical outpatient facility at the University of Alberta Hospital. This will allow for the observation of any infusion reactions and will also serve as nurse-provided self- infusion training sessions for patients. Participants will be assessed weekly for symptomatic change and reports of satisfaction and quality of life. The primary outcome variable is the change in the Quantitative Myasthenia Gravis (QMG) Score for Disease Severity from baseline to day 42 (6 weeks). A change of 3.5 points will be considered to be clinically significant. Safety and pharmacokinetic assessments of SCIG will be performed weekly throughout the study. Additionally, this study will be assessing the feasibility of employing SCIG as an alternative therapy to IVIG in patients with MG exacerbation. The cost-effectiveness of SCIG versus IVIG will be evaluated, and the impact of SCIG therapy will be assessed from both a health-resource perspective and from a patient perspective. The practicality of using SCIG in patients with MG will be determined by documenting the number of patients who are able to be trained for self- administration of SCIG, and by the patients' self-reported satisfaction with SCIG treatment. The speed of SCIG treatment onset will also be assessed and compared to IVIG treatment onset. All of these described measures will be used to determine the feasibility and practicality of using SCIG in patients with MG exacerbation and its impact on the healthcare system.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
26
Study medication is available in the following forms: 5 mL (1 g IgG) in a 5 mL infusion bottle, 10 mL (2 g IgG) in a 10 mL infusion bottle, 20 mL (4 g IgG) in a 20 mL infusion bottle, 50 mL (10 g IgG) in a 50 mL infusion bottle. Patients will be receiving 2gm/kg (150gm for a 75kg patient) of 20% SCIG (Hizentra) infused over four weeks in a dose escalating manner.
University of Alberta
Edmonton, Alberta, Canada
Vancouver General Hospital - Gordon & Leslie Diamond Health Care Centre
Vancouver, British Columbia, Canada
Change in Quantitative Myasthenia Gravis Score (QMGS) from baseline to day 42 after treatment.
QMGS is a validated clinical measure of myasthenia gravis ranging from 0 points (no myasthenic weakness) to a maximum of 39 points, with a defined change of 3.4 units required for clinical significance.
Time frame: Baseline - Day 42
Quality of life will be assessed through the Quality of Life (QOL) score, a qualitative questionnaire.
Time frame: Baseline - Day 42
Change in Manual Muscle Testing (MMT) score from baseline to day 42 after treatment.
MMT is a validated clinical measure of myasthenia gravis ranging from 0 points (no myasthenic weakness) to a maximum of 128 points, with a defined change of 25% from baseline required for clinical significance.
Time frame: Baseline - Day 42
Adverse events related to SCIG infusions will be recorded if/when they occur.
Time frame: Baseline - Day 42
Patient satisfaction with the treatment modality will be assessed using a questionnaire.
TQSM: Treatment Satisfaction Questionnaire for Medication. An 11 question ordinal scale measuring responses from "Extremely satisfied" to "Extremely dissatisfied" over a 7 item option list. Questions cover four domains, corresponding to distinct aspects related to the satisfaction of patients with their treatment (Effectiveness; Side effects; Convenience and Global satisfaction). A score can be obtained for each domain by summing of the corresponding items transformed on a 0-100 scale; higher values indicate higher satisfaction, better perceived effectiveness, lower burden associated to side-effects, better convenience
Time frame: Day 42
Serious Adverse Events related to SCIG infusions will be recorded if/when they occur.
Time frame: Baseline - Day 42
Proportion of participants successfully trained will be recorded indicating feasibility based on patient compliance.
Time frame: Baseline - Week 2
Proportion of participants completing will be recorded indicating feasibility based on patient compliance.
Time frame: Baseline - Day 42
Myasthenia Gravis (MG) Composite scores will be used to evaluate disease severity through a number of functional assessments, including muscle strength and ability to complete activities of daily living.
Time frame: Baseline - Day 42
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