Last reviewed 2026-04-20 · How we verify

Ultomiris (RAVULIZUMAB)

Ultomiris blocks the action of Complement C5 to prevent inflammation and damage to red blood cells.

Ultomiris (ravulizumab) is a complement inhibitor developed by Alexion Pharmaceuticals, targeting Complement C5. It is a monoclonal antibody, not a small molecule as initially stated, and is FDA-approved for treating atypical hemolytic uremic syndrome (aHUS), generalized myasthenia gravis, myasthenia gravis, and paroxysmal nocturnal hemoglobinuria. Ultomiris works by blocking the action of Complement C5, a protein that plays a key role in the complement system, which can cause inflammation and damage to red blood cells. As a patented product, it is not yet available as a generic. Key safety considerations include the risk of infusion-related reactions and the potential for increased susceptibility to infections.

At a glance

Mechanism of action

Ravulizumab-cwvz is terminal complement inhibitor that specifically binds to the complement protein C5 with high affinity, thereby inhibiting its cleavage to C5a (the proinflammatory anaphylatoxin) and C5b (the initiating subunit of the terminal complement complex [C5b-9]) and preventing the generation of the terminal complement complex C5b9. ULTOMIRIS inhibits terminal complement-mediated intravascular hemolysis in patients with PNH and complement-mediated thrombotic microangiopathy (TMA) in patients with aHUS.

Approved indications

• Atypical hemolytic uremic syndrome (aHUS)
• Generalized myasthenia gravis
• Myasthenia gravis
• Paroxysmal nocturnal hemoglobinuria

Boxed warnings

• WARNING: SERIOUS MENINGOCOCCAL INFECTIONS ULTOMIRIS, a complement inhibitor, increases the risk of serious infections caused by Neisseria meningitidis [see Warnings and Precautions (5.1) ] . Life-threatening and fatal meningococcal infections have occurred in patients treated with complement inhibitors. These infections may become rapidly life-threatening or fatal if not recognized and treated early . Complete or update vaccination for meningococcal bacteria (for serogroups A, C, W, Y, and B) at least 2 weeks prior to the first dose of ULTOMIRIS, unless the risks of delaying therapy with ULTOMIRIS outweigh the risk of developing a serious infection. Comply with the most current Advisory Committee on Immunization Practices (ACIP) recommendations for vaccinations against meningococcal bacteria in patients receiving a complement inhibitor. See Warnings and Precautions (5.1) for additional guidance on the management of the risk of serious infections caused by meningococcal bacteria. Patients receiving ULTOMIRIS are at increased risk for invasive disease caused by Neisseria meningitidis , even if they develop antibodies following vaccination. Monitor patients for early signs and symptoms of serious meningococcal infections and evaluate immediately if infection is suspected. Because of the risk of serious meningococcal infections, ULTOMIRIS is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called ULTOMIRIS and SOLIRIS REMS [see Warnings and Precautions (5.2) ]. WARNING: SERIOUS MENINGOCOCCAL INFECTIONS See full prescribing information for complete boxed warning. ULTOMIRIS increases the risk of serious and life-threatening infections caused by Neisseria meningitidis . Complete or update meningococcal vaccination at least 2 weeks prior to the first dose of ULTOMIRIS, unless the risks of delaying ULTOMIRIS outweigh the risks of developing a serious infection. Comply with the most current Advisory Committee on Immunization Practices (ACIP) recommendations for meningococcal vaccination in patients receiving a complement inhibitor. ( 5.1 ) Patients receiving ULTOMIRIS are at increased risk for invasive disease caused by N. meningitidis , even if they develop antibodies following vaccination. Monitor patients for early signs and symptoms of meningococcal infections and evaluate immediately if infection is suspected. ( 5.1 ) ULTOMIRIS is available only through a restricted program called ULTOMIRIS and SOLIRIS REMS. ( 5.2 )

Common side effects

• Upper respiratory tract infection
• Diarrhea
• Nausea
• Vomiting
• Pyrexia
• Hypertension
• Anemia
• Abdominal pain
• Fatigue
• Edema peripheral
• Headache
• Constipation

Key clinical trials

• Double-blind, Randomized, Placebo-controlled, Multicenter Study to Evaluate the Efficacy and Safety of Ravulizumab Administered Intravenously in Adult Participants at High Risk of Delayed Graft Function After Kidney Transplantation (PHASE3)
• Ravulizumab in Thrombotic Microangiopathy After Hematopoietic Stem Cell Transplant (PHASE3)
• Study of Ravulizumab in Immunoglobulin A Nephropathy (IgAN) (PHASE3)
• ARTEMIS: Ravulizumab to Protect Patients With CKD From CSA-AKI and MAKE (PHASE3)
• A Study in Adult Patients With Paroxysmal Nocturnal Hemoglobinuria (PNH) to Evaluate How Safe Long-term Treatment With Pozelimab + Cemdisiran Combination Therapy is and How Well it Works (PHASE3)
• Study of Ravulizumab in Pediatric Participants With Primary IgAN (PHASE3)
• Rituximab Versus Ravulizumab, Inebilizumab, Satralizumab, and Eculizumab in NMOSD (PHASE4)
• Ravulizumab Treatment Outcomes in Patients With Generalized Myasthenia Gravis

Patents

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Ultomiris CI brief — competitive landscape report
• Ultomiris updates RSS · CI watch RSS
• AstraZeneca portfolio CI