On June 27, 2023, UCB received U.S. Food and Drug Administration (FDA) approval of Rystiggo^® (rozanolixizumab-noli) for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive. Rystiggo is a neonatal Fc receptor (FcRn) blocker that decreases pathogenic Immunoglobulin G (IgG) autoantibodies. It is administered via a subcutaneous (SC) infusion pump over 20 to 30 minutes once weekly for six weeks. The infusion must be prepared and infused by a healthcare professional. The recommended dose is 420mg for patients weighing less than 50kg, 560mg for patients weighing 50kg to less than 100kg, and 840mg for patients weighing 100kg or more. Any vaccinations that are due should be given before patients begin treatment with Rystiggo. UCB plans to launch Rystiggo in the third quarter. Full prescribing information can be found here.

At a Glance

• Brand (Generic) Name: Rystiggo (rozanolixizumab-noli)
• Manufacturer: UCB
• Date Approved: June 27, 2023
• Indication: treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive
• Dosage Forms Available: single-dose vials containing 280mg/2mL (140mg/mL)
• Launch Date: third quarter of 2023
• Estimated Cost: Pricing information is not yet available.
• Caused by an autoimmune reaction that damages parts of muscles where nerve signals are received, gMG results in muscle weakness. Around one patient in 10 may have potentially fatal involvement of muscles used to breathe. Other symptoms may include double vision, drooping eyelids, and difficulty swallowing, chewing, and talking.
• Up to 60,000 Americans are estimated to have MG, which is more common among women than men. Women generally are diagnosed with the condition in early adulthood, but cases in men usually are not discovered until after the age of 50 years old.
• Approximately 85% of patients who have MG have the generalized type and about 85% of patients who have gMG also have AChR antibodies and another 6% of patients have MuSK antibodies.
• Approval of Rystiggo was based on a Phase III study that showed that treatment with it significantly improved patients’ everyday activities such as breathing, talking, swallowing, and being able to rise from a chair. This was measured as an improvement of the Myasthenia Gravis-Activities of Daily Living (MG-ADL) score from baseline [-3.4 points for Rystiggo-treated patients versus -0.8 points for those taking placebo (p<0.001)]. Common side effects may include headache, infections, diarrhea, pyrexia, hypersensitivity reactions, and nausea.
• Other drugs approved to treat gMG in patients who are AChR antibody-positive include Alexion’s intravenously (IV) infused complement inhibitors Soliris^® (eculizumab) and Ultomiris^® (ravulizumab-cwvz) and Argenx’s FcRn blockers Vyvgart^® (efgartigimod alfa-fcab) and Vyvgart^® Hytrulo (efgartigimod alfa/hyaluronidase-qvfc). Vyvgart is administered as an IV infusion and Vyvgart Hytrulo, which was approved on June 20, 2023, is administered as a SC infusion over approximately 30 to 90 seconds once weekly for four weeks.
• Rystiggo is the first drug for gMG that is also approved to treat patients who are MuSK antibody positive.
• Rystiggo was approved under Priority Review and is designated as an Orphan Drug.