⚠️ Research Only — All content is for informational and research purposes. Not medical advice. Read full disclaimer

Ravulizumab

Also known as: Ultomiris, ALXN1210

Ravulizumab is a long-acting humanized monoclonal antibody that inhibits terminal complement activation by blocking C5 cleavage. This complement inhibitor provides sustained protection against complement-mediated tissue damage with dosing every 8 weeks compared to every 2 weeks for eculizumab.

Last updated: February 24, 2026Reviewed by: Complement Research Team

Ravulizumab is a 146.8 kDa research peptide. Ravulizumab is a long-acting humanized monoclonal antibody that inhibits terminal complement activation by blocking C5 cleavage. This complement inhibitor provides sustained protection against complement-mediated tissue damage with dosing every 8 weeks compared to every 2 weeks for eculizumab.

Also called: Ultomiris, ALXN1210

146.8 kDa

Molecular Weight

Daltons

4

Strong Evidence

benefits

3

Studies Cited

peer-reviewed

2400-3000

Typical Dose

mg

Overview

Ravulizumab represents a significant advancement in complement system modulation for research applications investigating complement-mediated disorders. The antibody binds to complement protein C5 with high affinity, preventing its cleavage into C5a and C5b fragments. This blocks formation of the membrane attack complex (MAC), which causes cell lysis in complement-dependent pathologies. The Fc region has been engineered with four amino acid substitutions that extend half-life through enhanced FcRn binding and reduced lysosomal degradation. Research shows ravulizumab maintains >95% complement inhibition for 8 weeks after administration, making it valuable for studying long-term complement blockade effects. Studies examine its potential in paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and other complement-driven conditions. The extended dosing interval reduces treatment burden while maintaining efficacy comparable to more frequent complement inhibitors.

Key Takeaways: Ravulizumab

  • Strongest evidence supports Ravulizumab for extended complement inhibition and reduced hemolysis in pnh models
  • Research doses typically range from 2400 to 3000 mg via iv
  • 4 benefits with strong evidence, 1 moderate, 1 preliminary
  • Half-life: 49-55 days
  • 3 cited research studies in this guide

Mechanism of Action

Ravulizumab binds specifically to complement component C5, preventing its proteolytic cleavage by C5 convertase enzymes. This blocks formation of C5a anaphylatoxin and C5b, which initiates membrane attack complex assembly. The engineered Fc region contains M428L/N434S substitutions that increase FcRn binding affinity at acidic pH, extending circulating half-life through enhanced recycling and reduced catabolism.

Research Benefits

Ravulizumab at a Glance

Primary mechanism:

Ravulizumab binds specifically to complement component C5, preventing its proteolytic cleavage by C5 convertase enzymes.

Top researched benefits:
Extended Complement InhibitionReduced Hemolysis in PNH ModelsThrombotic Microangiopathy PreventionImproved Pharmacokinetic ProfileMyasthenia Gravis Research ApplicationsTransplant Rejection Studies

Extended Complement Inhibition

Strong Evidence

Provides sustained C5 blockade for 8 weeks with >95% inhibition maintained throughout dosing interval, enabling long-term complement research studies.

Reduced Hemolysis in PNH Models

Strong Evidence

Blocks complement-mediated destruction of PNH erythrocytes by preventing membrane attack complex formation, maintaining stable hemoglobin levels.

Thrombotic Microangiopathy Prevention

Strong Evidence

Inhibits complement activation on endothelial surfaces, reducing platelet consumption and microangiopathic changes in aHUS research models.

Improved Pharmacokinetic Profile

Strong Evidence

Engineered Fc region extends half-life to 49-55 days compared to 11 days for eculizumab, allowing less frequent dosing schedules.

Myasthenia Gravis Research Applications

Moderate Evidence

Shows potential for investigating complement-mediated neuromuscular junction damage by blocking C5-dependent membrane attack complex formation.

Transplant Rejection Studies

Preliminary

May reduce complement-mediated tissue damage in organ transplantation research by preventing C5b-9 complex formation on transplanted tissues.

Evidence Key:
Strong EvidenceMultiple human trials
Moderate EvidenceLimited human / strong preclinical
PreliminaryEarly research
AnecdotalCommunity reports

Research Dosing Protocols

Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.

Research ProtocolDose RangeRoute
PNH complement inhibition studies24003000 mgIV
aHUS research models27003000 mgIV
Long-term complement studies30003600 mgIV

Frequency

Every 8 weeks after loading doses

Timing

Loading dose on day 1, then maintenance every 56 days

Cycle Length

Ongoing as per research protocol

Research Notes

  • 1Weight-based dosing may be required for research protocols
  • 2Loading dose typically 15% higher than maintenance dose
  • 3Infuse over 25-45 minutes in clinical settings
  • 4Pre-medication with antihistamines may reduce infusion reactions

Reconstitution Guide

Standard Reconstitution

Vial Size

300 mg

Bacteriostatic Water

30 mL

Concentration

100 mcg

per 0.1 mL (10 units)

Step-by-Step Guide

1

Gather Materials

Ravulizumab vial, bacteriostatic water, alcohol swabs, insulin syringes.

2

Equilibrate Temperature

Remove the vial from storage and allow it to reach room temperature (5-10 minutes).

3

Sanitize

Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.

4

Draw Water

Draw 30 mL of bacteriostatic water into a syringe.

5

Add Water to Vial

Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.

6

Mix Gently

Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.

7

Store Properly

Refrigerate at 2-8°C. 24 months unopened, use immediately after dilution.

Storage Temperature

2-8°C

Shelf Life

24 months unopened, use immediately after dilution

Important Notes

  • Supplied as ready-to-use solution requiring dilution only
  • Dilute with 0.9% sodium chloride or 5% dextrose
  • Do not shake - gently invert to mix
  • Inspect for particulates before administration

Safety & Side Effects

Reported Side Effects

  • !Increased susceptibility to Neisseria infections
  • !Upper respiratory tract infections
  • !Headache and fatigue
  • !Infusion-related reactions (fever, chills)
  • !Nausea and abdominal pain
  • !Arthralgia and myalgia
  • !Hypertension during infusion
  • !Potential for immunogenicity with repeated dosing

Potential Interactions

  • Live vaccines contraindicated due to complement inhibition
  • Increased infection risk when combined with other immunosuppressants
  • May reduce effectiveness of complement-dependent therapies
  • Anticoagulants may have enhanced effects due to reduced thrombotic risk

Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.

Research Studies

The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.

Ravulizumab versus eculizumab in adults with paroxysmal nocturnal haemoglobinuria

Lee JW, Sicre de Fontbrune F, Wong Lee Lee L2019Blood
PMID: 30578203

Phase 3 trial demonstrated non-inferiority of ravulizumab to eculizumab for PNH treatment with improved quality of life due to extended dosing interval.

Ravulizumab in patients with paroxysmal nocturnal hemoglobinuria: results from 2 phase 1b/2 studies

Kulasekararaj AG, Hill A, Rottinghaus ST2019Blood Advances
PMID: 30617143

Dose-finding studies established optimal dosing regimens and confirmed sustained complement inhibition with 8-week dosing intervals.

Pharmacokinetics and pharmacodynamics of ravulizumab in adults with paroxysmal nocturnal hemoglobinuria

Roth A, Rottinghaus ST, Hill A2018Clinical Pharmacokinetics

Detailed analysis of ravulizumab PK/PD showing consistent complement inhibition and extended half-life compared to eculizumab.

Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.

Frequently Asked Questions

Ravulizumab has an engineered Fc region that extends its half-life to 49-55 days versus 11 days for eculizumab, allowing dosing every 8 weeks instead of every 2 weeks while maintaining equivalent complement inhibition.

Ravulizumab binds to complement protein C5, preventing its cleavage into C5a and C5b fragments. This blocks membrane attack complex formation and eliminates complement-mediated cell lysis.

Research shows ravulizumab maintains >95% complement inhibition for the full 8-week dosing interval, with some studies showing activity extending beyond 8 weeks.

The primary concern is increased susceptibility to Neisseria infections due to complement inhibition. Meningococcal vaccination is recommended before treatment initiation.

Pediatric dosing protocols exist based on weight-based calculations, though most research data comes from adult populations. Specialized pediatric formulations may be required.

Store at 2-8°C in original packaging protected from light. Do not freeze or shake. Use immediately after dilution for intravenous administration.

CH50 (total hemolytic complement activity) is the primary marker, with >95% reduction indicating adequate C5 blockade. LDH levels and reticulocyte counts help assess hemolysis in PNH research.

Live vaccines are contraindicated. Concomitant immunosuppressants may increase infection risk. The drug may affect complement-dependent diagnostic tests.

⚠️

Research & Educational Use Only

All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.

The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.