Safety of Anumigilimab (CSL324) in Adults With Sickle Cell Disease (SCD)

August 4, 2026 updated by: CSL Behring

Phase 2a, Multicenter, Randomized, Double-blind, Placebo-controlled Study to Assess the Safety of Anumigilimab (CSL324) in Adults With Sickle Cell Disease

This is a phase 2a, global, multicenter, randomized, double-blind, placebo-controlled study investigating the safety of anumigilimab administered subcutaneously (SC) at the maximum tolerated dose (MTD) in adult participants with SCD.

The primary aim of the study is to assess the safety of anumigilimab in participants with SCD. Participants will be treated for 64 weeks: for 12 weeks in the dose escalation period, where the dose will be escalated to each participant's individual MTD; and for 52 weeks at the MTD in the maintenance period.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
63

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Belgium
      • Brussels, Belgium, 1000
        • Recruiting
        • CHU Saint-Pierre
  • France
      • Nantes, France, 44093
        • Recruiting
        • CHU de Nantes, Hotel-Dieu
      • Toulou, France, 31100
        • Recruiting
        • Institut Universitaire du Cancer de Toulouse
  • Italy
      • Verona, Italy, 37134
        • Recruiting
        • AOUI Verona and University of Verona
  • United Kingdom
      • London, United Kingdom, NW10 7NS
        • Recruiting
        • Central Middlesex Hospital
      • London, United Kingdom, SW17 0QT
        • Recruiting
        • St George's University Hopsitals NHS Foundation Trust
      • London, United Kingdom, W120HS
        • Recruiting
        • Hammersmith Hospital Imperial College Healthcare NHS Trust
  • United States
    • Arkansas
      • Little Rock, Arkansas, United States, 72202
        • Recruiting
        • UAMS Medical Center
    • California
      • Orange, California, United States, 92868
        • Recruiting
        • University of California Irvine
    • Florida
      • Hollywood, Florida, United States, 33023-6703
        • Recruiting
        • The Foundation for Sickle Cell Disease
    • Georgia
      • Atlanta, Georgia, United States, 30329
        • Recruiting
        • Arthur M. Blank Hospital- Children's Healthcare of Atlanta
    • Maryland
      • Bethesda, Maryland, United States, 20817
        • Recruiting
        • Center for Cancer and Blood Disorders
    • Mississippi
      • Flowood, Mississippi, United States, 39232
        • Recruiting
        • Southern Specialty Research
    • New York
      • The Bronx, New York, United States, 10461
        • Recruiting
        • Jacobi Medical Center
    • Ohio
      • Columbus, Ohio, United States, 43210
        • Recruiting
        • Ohio State University
    • Virginia
      • Richmond, Virginia, United States, 23298
        • Recruiting
        • Virginia Commonwealth University

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged greater than or equal to (>=) 18 years on the day of signing the informed consent form.
  • Confirmed diagnosis of SCD of any genotype.
  • Experienced 1 to 12 VOCs requiring a visit to a medical facility and treatment with parenteral opioids or a parenteral nonsteroidal anti-inflammatory drug within the 12 months before Screening.
  • HU Regimen:
  • a. On stable and well-tolerated Hydroxyurea (HU) regimen for at least 30 days before Screening.
  • or
  • b. HU was discontinued or refused (eg, due to concern of side effects or lack of effect).

Exclusion Criteria:

  • Absolute neutrophil count less than (<) 2.5 ×10^9 cells/Litre at Screening or Baseline (Week 1 Day 1).
  • If on SCD preventive medication, dose is not stable in the 30 days before Screening.

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Anumigilimab
Safety of Anumigilimab (CSL324) in Adults with Sickle Cell Disease (SCD)
Biological: Anumigilimab
Participants will receive anumigilimab, escalated to a maximum dose guided by absolute neutrophil count (ANC) and safety concerns.
Placebo Comparator: Placebo
Participants will receive matching volume of placebo.
Drug: Placebo
Volume matched saline will be administered SC.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of participants with Treatment Emergent Adverse Events (TEAEs), Overall and by severity, seriousness and relationship to Investigational Product (IP)
Time Frame: From baseline up to Week 75
From baseline up to Week 75
Percentage of participants with TEAEs Overall and by severity, seriousness and relationship to IP
Time Frame: From baseline up to Week 75
From baseline up to Week 75
Number of participants with Adverse Events of Special Interest (AESI)
Time Frame: From baseline up to Week 75
The following AEs are to be reported as AESI: neutropenia (Common Terminology Criteria for Adverse Events [CTCAE] Grade 3 or 4), severe infection and neutropenic fever.
From baseline up to Week 75
Percentage of participants with AESI
Time Frame: From baseline up to Week 75
The following AEs are to be reported as AESI: neutropenia (CTCAE Grade 3 or 4), severe infection and neutropenic fever.
From baseline up to Week 75
Number of participants with clinically relevant changes from baseline in laboratory assessments and vital signs
Time Frame: From baseline up to Week 75
From baseline up to Week 75
Percentage of participants with clinically relevant changes from baseline in laboratory assessments and vital signs
Time Frame: From baseline up to Week 75
From baseline up to Week 75

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Serum concentration of Anumigilimab
Time Frame: From the first dose of anumigilimab to Week 65
From the first dose of anumigilimab to Week 65
Annualized rate of Vaso-occlusive crisis (VOC) (medical facility)
Time Frame: During the maintenance period from Week 13 to Week 65
VOC (medical facility) is defined as VOC that results in a visit to a medical facility and treatment with parenteral opioids or a parenteral nonsteroidal anti-inflammatory drug.
During the maintenance period from Week 13 to Week 65

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
CSL Behring

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Study Director, CSL Behring

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 2, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 29, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 29, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 31, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 31, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 4, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CSL324_2002
  • 2025-521154-42-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

CSL will consider on a case-by-case basis requests to share Individual Patient Data (IPD) with external bona-fide, qualified scientific and medical researchers. For information on the process and requirements for submitting a voluntary data sharing request for IPD, please contact CSL at clinicaltrials@cslbehring.com.

IPD Sharing Time Frame

Requests for IPD will generally be considered once review by major regulatory authorities (i.e. FDA, EMA) is complete and the primary publication is available.

IPD Sharing Access Criteria

Proposed research should seek to answer a previously unanswered important medical or scientific question.

Applicable country specific privacy and other laws and regulations will be considered and may prevent sharing of IPD.

If the request is approved and the researcher has executed an appropriate data sharing agreement, IPD that has been appropriately anonymized will be available.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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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