Active, not recruitingNCT06359002Updated Jan 20, 2026

Safety, Pharmacokinetics, and Preliminary Efficacy of BYON4413 in Acute Myeloid Leukemia and Myelodysplastic Neoplasms.

A Phase 1 interventional study of BYON4413 in Relapsed / Refractory AML and Relapsed / Refractory MDS, sponsored by Byondis B.V.. Active, not recruiting at 9 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-20.

Sponsored by Byondis B.V. · Phase 1, Interventional, and Treatment

Phase: Phase 1
Study type: Interventional
Enrollment: 16
Allocation: Not applicable
Ages: 18 Years and older
Sex: All

Study summary

This is the first-in-human trial with BYON4413 to evaluate safety, PK, immunogenicity, and anti-leukemia activity of BYON4413 in patients with AML or MDS.

Read the detailed description

This trial includes two parts. Part 1 is a dose escalation study in which the maximum tolerated dose and recommended dose for expansion of BYON4413 will be determined. Part 2 is an expansion study to evaluate the anti-leukemia activity and safety of BYON4413.

Conditions studied

Relapsed / Refractory AML
Relapsed / Refractory MDS

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Keywords

BYON4413
CD123
Hematologic Malignancies
Antibody Drug Conjugate
AML
MDS

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: All
Accepts healthy volunteers: No

Inclusion criteria

Patients who have progressed on standard therapy or have no established alternative treatment, with a diagnosis of:
- R/R AML (WHO 2022) OR
- MDS (WHO 2022) with ≥10% blasts in BM and have received ≥3 cycles of HMA
Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2;
Adequate baseline organ function.

Exclusion criteria

Exclusion Criteria:

Having been treated with any CD123-targeting therapies;
Having received allogeneic hematopoietic stem cell transplantation within 100 days prior to start Cycle 1 Day 1;
Having treatment-related toxicities from prior anti-leukemia therapies that have not resolved to CTCAE Grade ≤ 1;
Having active central nervous system AML or AML of the APL/M3 subtype;
History of keratitis;
History of specified lung or renal disease;
Having clinically significant cardiovascular disease;
Known infection of Hepatitis B, C or E.

Key inclusion and exclusion criteria details are listed here, additional requirements may apply.

Study design

Phase: Phase 1
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Sequential assignment
Masking: None (open label)
Enrollment: 16 participants (actual)

Study arms

Experimental
Dose Escalation
Escalating dose cohorts of BYON4413 for patients with AML or MDS.
Drug: BYON4413

Interventions

DrugBYON4413
BYON4413 will be administered by IV infusion.

What researchers measure

Primary outcomes

Incidence of dose-limiting toxicities (dose escalation)
Time frame: 21 days
Composite Complete Remission Rate (expansion)
CR + CRh + CRi according ELN 2022 criteria
Time frame: Up to 24 months

Secondary outcomes

Incidence and severity of adverse events
Time frame: Up to 24 months
Number of patients with dose modifications
Time frame: Up to 24 months
Rate of early death
Time frame: Within 3 treatment cycles
Maximum Plasma Concentration (Cmax) BYON4413
Time frame: Up to 24 months
Time to Cmax (Tmax) BYON4413
Time frame: Up to 24 months
Area under the curve (AUC) BYON4413
Time frame: Up to 24 months
Percentage of patients with confirmed anti-BYON4413 antibodies
Time frame: Up to 24 months
Composite Complete Remission Rate (dose escalation)
CR + CRh + CRi according ELN 2022 criteria
Time frame: Up to 24 months
Percentage of blasts in bone marrow change from baseline
Time frame: Up to 24 months
Percentage of blasts in peripheral blood change from baseline
Time frame: Up to 24 months
Objective response rate
CR + CRh + CRi + MLFS + PR according ELN 2022 criteria
Time frame: Up to 24 months
Duration of response
Time frame: Up to 24 months
Relapse-free survival
Time frame: Up to 24 months
Event-free survival
Time frame: Up to 24 months
Time to response
Time frame: Up to 24 months
Overall survival
Time frame: Up to 24 months

Study locations

9 sites

Het Ziekenhuisnetwerk Antwerpen
Antwerp, Belgium
UZ Leuven
Leuven, Belgium
Universitair Medisch Centrum Groningen
Groningen, Netherlands
Institut Catala d'Oncologia
Badalona, Spain
Hospital Clinic de Barcelona
Barcelona, Spain
Hospital de la Santa Creu i Sant Pau
Barcelona, Spain
Hospital San Pedro de Alcantara
Cáceres, Spain
Hospital Universitario de Salamanca
Salamanca, Spain
Hospital Universitario y Politecnico La Fe
Valencia, Spain

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

Registry details

Key details

Study ID: NCT06359002
Lead sponsor: Byondis B.V.
Responsible party: Sponsor
First posted: Apr 11, 2024
Start date: Jun 25, 2024
Primary completion: Sep 30, 2025
Completion: Feb 2026 (estimated)
Last update: Jan 20, 2026

Oversight

Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.

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