A Study to Assess Adverse Events and How Intravenous (IV) Pivekimab Sunirine Moves Through the Body in Pediatric Participants With Relapsed or Refractory Acute Myeloid Leukemia (AML)

A Phase 1b Study of the Safety and Pharmacokinetics of Pivekimab Sunirine in Pediatric Subjects With Relapsed or Refractory Acute Myeloid Leukemia (AML)

Acute myeloid leukemia (AML) is an aggressive blood cancer, withwith few options for participants who relapse after treatment or who don't respond to treatment. This study will assess the adverse events and how pivekimab sunirine moves through the body in pediatric participants with relapsed or refractory (R/R) AML.

Pivekimab sunirine is a drug being evaluated in the treatment of AML. This is an open label, single arm study, participants will be enrolled in 1 of the 3 cohorts based on their age and will receive pivekimab sunirine at a dose based on their weight. Around 18 pediatric participants with a diagnosis of AML will be enrolled in the study at approximately 30 sites around the world.

Participants will receive intravenous (IV) pivekimab sunirine alone. The total study duration is approximately 28 months.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, and checking for side effects.

Study Overview

• Status: Recruiting
• Conditions: Acute Myeloid Leukemia
• Intervention / Treatment: Drug: Pivekimab Sunirine

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: ABBVIE CALL CENTER; Phone Number: 844-663-3742; Email: abbvieclinicaltrials@abbvie.com

Study Locations

• Australia
  • Western Australia
    • Perth, Western Australia, Australia, 6009
      • Recruiting
      • Perth Children'S Hospital /ID# 275673
• Taiwan
  • Taipei, Taiwan, 100
    • Recruiting
    • National Taiwan University Hospital /ID# 276635
• United States
  • California
    • Palo Alto, California, United States, 94304
      • Recruiting
      • Lucile Packard Children's Hospital /ID# 276015
  • New York
    • Valhalla, New York, United States, 10595
      • Recruiting
      • New York Medical College /ID# 275597
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Recruiting
      • Tristar Centennial Medical Center /ID# 275831

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Must have histologically confirmed acute myeloid leukemia (AML) meeting one of the following disease criteria:

  • Second or greater relapse. OR
  • Disease refractory to second or subsequent line of therapy (defined as resistant disease after at least one cycle of each treatment regimen).
• Must have myeloid leukemic blasts that are CD123-positive by flow cytometry as determined by the treating institution.
• Has >= 5% myeloid leukemic blasts in bone marrow at time of relapse or refractory disease and prior to Screening for this study.
• Performance status by Lansky (< 16 years old at evaluation) or Karnofsky (>= 16 years old at evaluation) score >= 50 or ECOG score <= 2.
• May have status of central nervous system (CNS)1, CNS2, or CNS3 disease without clinical signs or neurologic symptoms suggestive of CNS leukemia, such as facial nerve palsy, brain/eye involvement or hypothalamic syndrome. Participants receiving intrathecal therapy and no additional CNS-directed systemic therapy at study entry are eligible and may continue treatment as clinically indicated in accordance with institutional practice.
• For those participants who have not reached the age of consent, parent or legal guardian with the willingness and ability to provide informed consent and participant willing and able to give assent, as appropriate for age and country.

Exclusion Criteria:

• Known clinically significant cardiac disease.
• Down syndrome.
• Acute promyelocytic leukemia (APL) or juvenile myelomonocytic leukemia (JMML).
• Symptomatic central nervous system (CNS3) disease
• Prior history of any severity veno-occlusive disease/sinusoidal obstructive syndrome (VOD/SOS) of the liver.
• Prior history of hematopoietic stem cell transplant within 6 months prior to Screening without evidence of active GvHD at the time of screening and the participant is off medications to treat or prevent either post-transplant graft-versus-host disease (GvHD) or post-transplant rejection (except for a stable dose of corticosteroids).
• Have received prior Chimeric Antigen Receptor T-cell (CAR-T) therapy.
• Any other known current malignancy requiring therapy.
• Currently receiving anticancer therapy with antineoplastic intent, including radiotherapy, systemic therapy small molecules, monoclonal antibodies, other investigational agents, or high-dose chemotherapy with the exception of intrathecal therapy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1: Pivekimab Sunirine Ages 2 to < 6 Years; Participants will receive pivekimab sunirine, as part of the approximately 28 month study duration. If enrolled, subjects aged 6 months to less than 2 years will be included in Cohort 1	Drug: Pivekimab Sunirine; Intravenous
Experimental: Cohort 2: Pivekimab Sunirine Ages 6 to < 12 Years; Participants will receive pivekimab sunirine, as part of the approximately 28 month study duration.	Drug: Pivekimab Sunirine; Intravenous
Experimental: Cohort 3: Pivekimab Sunirine Ages 12 to < 17 Years; Participants will receive pivekimab sunirine, as part of the approximately 28 month study duration.	Drug: Pivekimab Sunirine; Intravenous

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants with Treatment-Emergent Adverse Events (TEAEs) Leading to Treatment Discontinuation	Number of participants with protocol specified Treatment-Emergent Adverse Events (TEAEs) during and after treatment with pivekimab sunirine (PVEK). Severity of TEAEs will be graded according to the National Cancer Institute (NCI) Common Toxicity Criteria for Adverse Events (CTCAE) version 5.0.	Up to Approximately 24 Months
Maximum Observed Serum/Plasma Concentration (Cmax) of Intact Antibody-Drug Conjugate (ADC)	Maximum observed serum/plasma concentration of intact ADC.	Up to Approximately 22 Months
Cmax of FGN849 Payload	Maximum observed serum/plasma concentration of FGN849 payload.	Up to Approximately 22 Months
Area Under the Concentration-Time Curve (AUC) of Intact ADC	Area under the concentration-time curve of intact ADC.	Up to Approximately 22 Months
AUC of FGN849 payload	Area under the concentration-time curve of FGN849 payload.	Up to Approximately 22 Months
Time to Cmax (Tmax) of Intact ADC	Time to Cmax of intact ADC.	Up to Approximately 22 Months
Tmax of FGN849 Payload	Time to Cmax of payload.	Up to Approximately 22 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving Composite Complete Remission (CR + complete remission with incomplete recovery [CRi])	Percentage of participants achieving CR + CRi.	Up to Approximately 28 Months
Percentage of Participants Achieving Composite Complete Remission (CR + complete remission with partial hematological [CRh])	Percentage of participants achieving CR + CRh.	Up to Approximately 28 Months
Duration of Complete Remission (DOCR)	DOCR is defined as the first response of CR to the time of relapse or death from any cause, whichever comes first; for participants who did not relapse or die, the duration will be censored at the time of the last response assessment.	Up to Approximately 28 Months
Duration of Composite Complete Remission (CR + CRi)	Duration of composite complete remission (CR + CRi).	Up to Approximately 28 Months
Duration of Composite Complete Remission (CR + CRh)	Duration of composite complete remission (CR + CRh).	Up to Approximately 28 Months
Percentage of Participants Achieving Complete Remission (CR)	CR is defined as Hematologic recovery: Absolute Neutrophil Count (ANC) > 1.0 × 10^9/L (> 1,000/μL) and platelet count > 100 × 10^9/L (> 100,000/μL); < 5% bone marrow blasts; absence of circulating blasts; no evidence of extramedullary disease; no transfusions or support by exogenous growth factors (GCSF) within 7 days prior to response evaluation.	Up to Approximately 28 Months

Collaborators and Investigators

• Sponsor: AbbVie
• Investigators: Study Director: ABBVIE INC., AbbVie

Publications and helpful links

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start (Actual): May 20, 2026
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): March 1, 2030

Study Registration Dates

• First Submitted: December 15, 2025
• First Submitted That Met QC Criteria: December 15, 2025
• First Posted (Actual): December 29, 2025

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Acute Myeloid Leukemia; Pediatric; Relapsed; Refractory; Pivekimab Sunirine; PVEK
• Additional Relevant MeSH Terms: Pathologic Processes; Neoplasms; Disease Attributes; Neoplasms by Histologic Type; Hematologic Diseases; Leukemia, Myeloid; Leukemia; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; Recurrence; Leukemia, Myeloid, Acute
• Other Study ID Numbers: M25-692; 2024-520125-36 (Other Identifier: EU CT)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No