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

NCT07224360 | Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: CSL324_20022025-521154-42-00
• Study Type: interventional
• Target: 63
• Locations: 1 country
• Sites: 5

Brief Summary

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.

Conditions

Sickle Cell Disease

Keywords

Anemia; Genetic Disorder; Vaso-occlusive Crises

Outcome Measures

Primary Outcomes (6)

• Number of participants with Treatment Emergent Adverse Events (TEAEs), Overall and by severity, seriousness and relationship to Investigational Product (IP)

  From baseline up to Week 75

• Percentage of participants with TEAEs Overall and by severity, seriousness and relationship to IP

  From baseline up to Week 75

• Number of participants with Adverse Events of Special Interest (AESI)

  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

  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

  From baseline up to Week 75

• Percentage of participants with clinically relevant changes from baseline in laboratory assessments and vital signs

  From baseline up to Week 75

Secondary Outcomes (2)

• Serum concentration of Anumigilimab

  From the first dose of anumigilimab to Week 65

• Annualized rate of Vaso-occlusive crisis (VOC) (medical facility)

  During the maintenance period from Week 13 to Week 65

Study Arms (2)

Anumigilimab

EXPERIMENTAL

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

Biological: Anumigilimab

Placebo

PLACEBO COMPARATOR

Participants will receive matching volume of placebo.

Drug: Placebo

Interventions

Anumigilimab BIOLOGICAL

Participants will receive anumigilimab, escalated to a maximum dose guided by absolute neutrophil count (ANC) and safety concerns.

Anumigilimab

Placebo DRUG

Volume matched saline will be administered SC.

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.
• b. HU was discontinued or refused (eg, due to concern of side effects or lack of effect).

You may not qualify if:

• 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.

Sponsors & Collaborators

• CSL Behring: lead

Study Sites (5)

UAMS Medical Center

Little Rock, Arkansas, 72202, United States

RECRUITING

The Foundation for Sickle Cell Disease

Hollywood, Florida, 33023-6703, United States

RECRUITING

Center for Cancer and Blood Disorders

Bethesda, Maryland, 20817, United States

RECRUITING

Southern Specialty Research

Flowood, Mississippi, 39232, United States

RECRUITING

Jacobi Medical Center

The Bronx, New York, 10461, United States

RECRUITING

MeSH Terms

Conditions

Anemia, Sickle Cell; Anemia; Genetic Diseases, Inborn; Vaso-Occlusive Crises

Condition Hierarchy (Ancestors)

Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Hematologic Diseases; Hemic and Lymphatic Diseases; Hemoglobinopathies; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Study Director

  CSL Behring

  STUDY DIRECTOR

Central Study Contacts

Trial Registration Coordinator

CONTACT

+1 610-878-4697; clinicaltrials@cslbehring.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This is a double blind, placebo controlled study.

Study Record Dates

• First Submitted: October 31, 2025
• First Posted: November 4, 2025
• Study Start: February 2, 2026
• Primary Completion (Estimated): June 29, 2028
• Study Completion (Estimated): June 29, 2028
• Last Updated: May 12, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• 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.
• 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.

Locations

US (5)