WHAT IS THE REIMBURSEMENT RECOMMENDATION FOR ZILBRYSQ?: Canada’s Drug Agency (CDA-AMC) recommends that Zilbrysq be reimbursed by public drug plans for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti–acetylcholine receptor (AChR) antibody positive and who continue to receive standard therapy if certain conditions are met. WHICH PATIENTS ARE ELIGIBLE FOR COVERAGE? Zilbrysq should only be covered to treat adult patients who have received treatment for at least 1 year with 2 or more immunosuppressant therapies; or who have a history of treatment with at least 1 immunosuppressant for 1 year or more, and chronic plasma exchange, IV immunoglobulin, or subcutaneous immunoglobulin at least every 3 months for 12 months. Eligible patients should test positive for AChR antibodies, have a Myasthenia Gravis Activities of Daily Living (MG-ADL) score (which estimates patients’ ability to perform activities of daily living; score ranges from 0 to 24, with higher scores indicating more impairment) of 6 or greater, and meet the Myasthenia Gravis Foundation of America (MGFA) classification (which categorizes clinical features by increasing severity) of II (mild weakness affecting body muscles and may also include weakness in the eye muscles) to IV (severe weakness affecting body muscles and may also include weakness in the eye muscles). WHAT ARE THE CONDITIONS FOR REIMBURSEMENT? Zilbrysq should not be given during a gMG exacerbation (moment when patient experiences weakness in some or all muscles, without needing assistance to breath) or crisis (moment when respiratory muscles are too weak, limiting air flow in and out of lungs, as a result patient is unable to breathe), or within 12 months of thymectomy (surgical removal of thymus gland). Zilbrysq should only be reimbursed if prescribed by or in consultation with a neurologist with expertise in managing patients with gMG and the cost of Zilbrysq is reduced. Zilbrysq should not be used concomitantly with rituximab, efgartigimod alfa, or complement inhibitors, such as eculizumab. WHY DID CDA-AMC MAKE THIS RECOMMENDATION? • Evidence from a clinical trial (RAISE) demonstrated that compared with placebo, treatment with Zilbrysq was associated with meaningful improvements in patients’ ability to perform activities of daily living and health-related quality of life (HRQoL), as well as a reduction in gMG symptom severity. • Zilbrysq met some of the identified patient needs as it improves the ability to perform activities of daily living and HRQoL, as well as reduces gMG symptom severity. It may also offer a faster onset of action and a subcutaneous drug option that can be administered in a patient’s home. • Based on the CDA-AMC assessment of the health economic evidence, Zilbrysq does not represent good value to the health care system at the public list price. A price reduction is therefore required. • Based on public list prices, Zilbrysq is estimated to cost the public drug plans approximately $82 million over the next 3 years.
WHAT IS GMG? Myasthenia gravis (MG) is a condition that causes muscle weakness. In some patients, symptoms remain exclusively to the eyes (ocular MG); however, most patients either are diagnosed with or progress within a few years to gMG, which affects the head and neck and other muscles. Symptoms of gMG include eyelid drooping and double vision, altered facial expression, difficulty chewing and swallowing food, difficulty speaking, and, in patients with more severe disease, problems with limb movement and breathing. When patients are unable to control their symptoms with conventional therapies, they are considered to have refractory gMG. In Canada, the incidence of MG is estimated at approximately 23 cases per 1 million population annually. UNMET NEEDS IN GMG: Patients with refractory gMG whose symptoms persist despite adequate treatment with conventional therapies have few treatment options. HOW MUCH DOES ZILBRYSQ COST? Treatment with Zilbrysq is expected to cost approximately $237,512 to $463,577 per patient per year, depending on patient weight.
