Post-Marketing Clinical Study of Ravulizumab in Participants With Clinical aHUS

April 17, 2026 updated by: Alexion Pharmaceuticals, Inc.

Multicenter, Open-label, Single-arm, Post-Marketing Clinical Study to Evaluate the Efficacy and Safety of Ravulizumab in Participants Clinically Diagnosed as Atypical Hemolytic Uremic Syndrome

The primary objective of this study is to assess the platelet count response to ravulizumab in participants clinically diagnosed as atypical hemolytic uremic syndrome (aHUS).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Japan
      • Bunkyō City, Japan, 113-8655
        • Not yet recruiting
        • Research Site
      • Hirakata-shi, Japan, 573-1191
        • Not yet recruiting
        • Research Site
      • Iruma-Gun, Japan, 350-0495
        • Recruiting
        • Research Site
      • Kyoto, Japan, 602-8566
        • Not yet recruiting
        • Research Site
      • Matsumoto-shi, Japan, 390-8621
        • Not yet recruiting
        • Research Site
      • Miyazaki, Japan, 889-1692
        • Not yet recruiting
        • Research Site
      • Nagoya, Japan, 466-8650
        • Recruiting
        • Research Site
      • Nara, Japan, 630-8581
        • Not yet recruiting
        • Research Site
      • Nerima-ku, Japan, 177-8521
        • Not yet recruiting
        • Research Site
      • Sapporo, Japan, 060-8638
        • Not yet recruiting
        • Research Site
      • Shinjuku-ku, Japan, 162-8666
        • Not yet recruiting
        • Research Site
      • Tsu, Japan, 514-8507
        • Recruiting
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Body weight ≥20 kilograms (kg)
  • Participants clinically diagnosed as aHUS who have any of diseases/conditions listed below (including participants in whom Thrombotic microangiopathy (TMA) has not been improved even after treatment for the pathogenesis of diagnosed secondary TMA and therefore, diagnosis of aHUS was made).
  • Infection (except for pneumococcal infection and Siga toxin-producing Escherichia coli infection)
  • During pregnancy or postpartum
  • Post-renal transplantation
  • Hypertensive crisis/malignant hypertension
  • Systemic lupus erythematosus and related diseases (e.g. dermatomyositis, mixed connective tissue disease, etc.)
  • Participants with the following three signs:
  • Thrombocytopenia: Platelet count <150,000/microliter (μL)
  • Microangiopathic haemolytic anaemia: Hb < 10 grams per deciliter (g/dL) (*)
  • Acute kidney injury: one of the following is fulfilled; 1. ΔsCr ≥ 0.3 milligrams per deciliter (mg/dL) (within 48 hours), 2. 1.5-fold increase from baseline sCr (within 7 days), 3. urinary output ≤ 0.5 mL/kg/hour for ≥ 6 hours.
  • No prior treatment with complement inhibitors.
  • The investigator plans to provide the participant with 26-week treatment with ravulizumab in accordance with the treatment policy in clinical practice.
  • Ravulizumab treatment is planned to be initiated within 14 days after onset of the latest TMA episode.
  • Participants consenting to meningococcal vaccine administration and appropriate antibiotic prophylaxis (if required).

Exclusion Criteria:

  • Participants with TTP, STEC-HUS, secondary TMA that is obviously unrelated to complement abnormality.
  • Participants with TMA caused by malignant tumors, abnormal Cobalamin C metabolism, Streptococcus pneumoniae, drugs, autoimmune diseases other than systemic lupus erythematosus and related diseases (e.g. scleroderma etc.), or hematopoietic stem cell transplantation
  • Participants with pathological complement gene variants (CFH, CFI , CD46 (MCP), C3, CFB, THBD, DGKE) associated with the development of aHUS at enrolment
  • Participants with positive anti-factor H antibodies
  • More than 14 day from onset of TMA to the planned start of ravulizumab treatment
  • Chronic kidney disease or irreversible renal impairment that requires chronic dialysis
  • Presence of unresolved meningococcal disease
  • Judgement by the investigator that the participant is not eligible for the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Ravulizumab
Participants will receive a weight-based loading dose of ravulizumab, followed by a weight-based dose 2 weeks after loading dose administration, then weight-based maintenance doses every 8 weeks via intravenous (IV) infusion.
Drug: Ravulizumab
Participants will receive ravulizumab via IV infusion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percentage of Participants Showing Improvement in Platelet Count During the 26-week Ravulizumab Treatment
Time Frame: Baseline up to Week 26
Baseline up to Week 26

Secondary Outcome Measures

Outcome Measure
Time Frame
Percentage of Participants Showing Improvement in Renal Function During the 26-week Ravulizumab Treatment
Time Frame: Baseline up to Week 26
Baseline up to Week 26
Percentage of Participants Showing Improvement in Platelet Count
Time Frame: Day 4 and on Weeks 1, 2, 10, 18, and 26
Day 4 and on Weeks 1, 2, 10, 18, and 26
Percentage of Participants Showing Improvement in Renal Function
Time Frame: Day 4 and on Weeks 1, 2, 10, 18, and 26
Day 4 and on Weeks 1, 2, 10, 18, and 26
Percentage of Participants Showing Improvement in Complete Thrombotic Microangiopathy (TMA) Response or Partial TMA Response
Time Frame: Day 4 and on Weeks 1, 2, 10, 18, and 26
Day 4 and on Weeks 1, 2, 10, 18, and 26
Percentage of Participants who are on Dialysis on Day 1 and are Able to Withdraw From Dialysis by Week 26
Time Frame: Baseline (Day 1) up to Week 26
Baseline (Day 1) up to Week 26
Change from Baseline in Platelet Count
Time Frame: Baseline (Day 1), Week 26
Baseline (Day 1), Week 26
Change From Baseline in Hemoglobin
Time Frame: Baseline (Day 1), Week 26
Baseline (Day 1), Week 26
Change From Baseline in Lactate Dehydrogenase
Time Frame: Baseline (Day 1), Week 26
Baseline (Day 1), Week 26
Change From Baseline in Estimated Glomerular Filtration Rate
Time Frame: Baseline (Day 1), Week 26
Baseline (Day 1), Week 26

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Alexion Pharmaceuticals, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 19, 2025

Primary Completion (Estimated)

June 25, 2027

Study Completion (Estimated)

June 25, 2027

Study Registration Dates

First Submitted

December 17, 2025

First Submitted That Met QC Criteria

December 17, 2025

First Posted (Actual)

December 29, 2025

Study Record Updates

Last Update Posted (Actual)

April 20, 2026

Last Update Submitted That Met QC Criteria

April 17, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • D928BL00001
  • NEPH-ULT-501 (Registry Identifier: Alexion)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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