Zilbrysq now approved in Canada to treat adults with generalized MG
Injection therapy for AChR-positive patients can be given at home
UCB’s injection therapy Zilbrysq (zilucoplan) has gained approval in Canada for treating adults with generalized myasthenia gravis (gMG) who are positive for antibodies targeting the acetylcholine receptor (AChR).
The decision by Health Canada was supported by results from the Phase 3 RAISE trial (NCT04115293), in which the treatment — given once daily via a self-administered subcutaneous, or under-the-skin, injection — significantly reduced symptom severity and improved patients’ quality of life.
“Health Canada’s approval of Zilbrysq marks a significant milestone for UCB Canada,” Rodrigo Reis, country lead of UCB Canada, said in a company press release. “As our first step in supporting the gMG community in Canada, this achievement represents a breakthrough in a new therapeutic area for our company.”
Zilbrysq is now the first and only gMG treatment in Canada that can be self-administered, which is expected to be more convenient and flexible for patients. The newly approved therapy is expected to become available by the end of the year.
The treatment is cleared for a similar indication in the U.S. and the European Union. It also is approved in Japan for gMG patients who respond poorly to steroids or other immunosuppressive treatments.
Muscular Dystrophy Canada welcomes Zilbrysq approval by Health Canada
According to Stacey Lintern, CEO of Muscular Dystrophy Canada, Zilbrysq’s approval “brings new hope for people with gMG, introducing a treatment option that promises to enhance the quality of life for many Canadians.”
“This progress marks a significant step forward in the ongoing need for improved and accessible treatment options for gMG, offering renewed optimism for patients and their families,” Lintern added.
MG is driven by self-reactive antibodies that target proteins in the neuromuscular junction, which is the site where nerve and muscle cells communicate to coordinate movements. In most cases, these autoantibodies target the AChRs at the surface of muscle cells.
When antibodies bind to AChR, they trigger the activation of the complement system, a group of immune proteins present in the blood that normally become activated to fight off bacteria and other pathogens. In gMG, however, the complement proteins contribute to muscle damage and symptoms like muscle weakness and fatigue.
Zilbrysq is a small molecule that blocks complement activation by targeting the complement protein C5. This protein also is the target of other gMG-approved therapies, such as Soliris (eculizumab) and Ultomiris (ravulizumab-cwvz).
The RAISE trial enrolled 174 gMG patients, ages 18-74, who were randomly assigned to receive either Zilbrysq, at a daily dose of 0.3 mg per kg of body weight, or a placebo, for three months.
The results showed that treatment with Zilbrysq led to a clinically meaningful reduction in MG Activities of Daily Living (MG-ADL) scores compared with the placebo. The MG-ADL scale measures MG symptom severity and how much symptoms interfere with patients’ day-to-day lives.
Until now, Canadians living with gMG have only had access to [treatments] intravenously, which can be time-consuming and burdensome for the health care system. … Health Canada’s approval of [Zilbrysq] … addresses a great unmet need.
Participants who completed the trial entered the ongoing RAISE-XT extension study (NCT04225871), which is evaluating the long-term safety and efficacy Zilbrysq. Recently reported data after one year indicated the clinical responses were sustained for more than one year.
“Until now, Canadians living with gMG have only had access to C5 therapy intravenously, which can be time-consuming and burdensome for the health care system,” said Angela Genge, MD, medical director of the clinical research unit at the Montreal Neurological Institute, one of the RAISE trial sites.
“Health Canada’s approval of the first once-daily and only self-administered C5 complement inhibitor that provides significant and clinically meaningful improvements addresses a great unmet need,” Genge added.
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