Rystiggo

Rystiggo Overview:

Rystiggo (rozanolixizumab-noli) is a biologic therapy for adults with generalized myasthenia gravis (gMG) who test positive for anti-acetylcholine receptor (AChR) or anti-muscle-specific kinase (MuSK) antibodies. Myasthenia gravis is a chronic autoimmune disease that causes muscle weakness and fatigue. Rystiggo is made by UCB and was approved by the FDA in June 2023. It is one of the few gMG treatments approved for both AChR and MuSK antibody–positive patients.

Understanding Rystiggo:

In myasthenia gravis, IgG autoantibodies attack the junction where nerves signal muscles, which causes weakness in the eyes, face, throat, limbs, and breathing muscles. Rystiggo is a humanized monoclonal antibody that blocks the neonatal Fc receptor (FcRn). FcRn normally recycles IgG antibodies and keeps them in circulation. When Rystiggo blocks FcRn, IgG, including the disease-causing autoantibodies, breaks down faster and IgG levels drop. This can improve symptoms such as drooping eyelids, double vision, difficulty swallowing or speaking, limb weakness, and shortness of breath.

Unlocking Rystiggo’s Potential:

Rystiggo is given as a subcutaneous infusion (under the skin) in the lower abdomen, using an infusion pump. Each infusion takes only minutes, and treatment is given in cycles. FDA approval was based on the Phase 3 MycarinG trial, in which patients treated with Rystiggo had significantly greater improvement in daily function, measured by the MG-ADL (Activities of Daily Living) scale, than patients given placebo.

Navigating Dosage and Administration:

• Dose: Based on body weight: 420 mg, 560 mg, or 840 mg per infusion.
• Schedule: One infusion per week for 6 weeks. This makes up one treatment cycle.
• Later cycles: Further cycles are scheduled based on the patient’s clinical evaluation. The safety of starting a new cycle sooner than 63 days after the previous cycle has not been established.
• Administration: Prepared and given by a healthcare provider as a subcutaneous infusion with an infusion pump. Infusion sites in the abdomen are rotated.
• Missed dose: A missed dose may be given up to 4 days after the scheduled time.
• Monitoring: Patients are watched for hypersensitivity reactions during the infusion and for 15 minutes afterward.

Preparing for Rystiggo Treatment:

Before starting treatment, the care team reviews:

• The patient’s diagnosis and antibody test results
• Any current infections
• Vaccination status
• Current medications
• Pregnancy or breastfeeding plans

Age-appropriate vaccinations should be completed before a new treatment cycle starts. Live or live-attenuated vaccines are not recommended during treatment. Rystiggo can lower the levels, and possibly the effectiveness, of other drugs that depend on FcRn, such as IV immunoglobulin (IVIG) and some monoclonal antibodies, so the care team plans the timing of these products carefully.

Rystiggo Side Effects:

The most common side effects in clinical trials included:

• Headache
• Infections
• Diarrhea
• Fever (pyrexia)
• Hypersensitivity reactions, such as rash
• Nausea

Serious but less common risks include:

• Infections: Because Rystiggo lowers IgG levels, it may increase infection risk. Dosing is delayed if a patient has an active infection.
• Aseptic meningitis: Serious cases have been reported. Patients should report severe headache, fever, stiff neck, nausea, vomiting, or sensitivity to light right away.
• Hypersensitivity reactions: These can include angioedema and rash. The infusion is stopped if a reaction occurs.

Healthcare providers monitor patients closely and act promptly if any reaction occurs.

Empowering Myasthenia Gravis Management with Rystiggo:

Rystiggo is a targeted way to manage generalized myasthenia gravis. It lowers the disease-causing autoantibodies directly rather than broadly suppressing the immune system. Short weekly subcutaneous infusions, a cycle-based schedule that adapts to each patient, and approval for both AChR and MuSK antibody–positive gMG make it an important option for improving muscle strength, daily function, and quality of life.