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Active, not recruitingNCT06932952Updated Jan 16, 2026

A Dose Escalation and Expansion Trial With BYON4228 Alone and in Combination in Patients With Advanced or Metastatic Solid Tumors

A Phase 1 interventional study of BYON4228 + Pembrolizumab in Solid Tumor, sponsored by Byondis B.V.. Active, not recruiting at 6 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-16.

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

Phase
Phase 1
Study type
Interventional
Enrollment
7
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This is a phase I trial with BYON4228, a humanized monoclonal antibody (mAb) directed against signal regulatory protein (SIRP)α in solid tumors, alone and in combination with pembrolizumab.

Read the detailed description

This study includes a dose escalation part (Part 1) in which the MTD or OBD and RDE(s) will be determined. This trial includes an expansion part (Part 2) to evaluate efficacy and safety of BYON4228 in combination with pembrolizumab in specific patient cohorts.

BYON4228 is a humanized IgG1 mAb directed against SIRPα. BYON4228 binds SIRPα expressed on innate immune cells, especially monocytes, macrophages and neutrophils. BYON4228 blocks binding of SIRPα to CD47 and inhibits signaling through the CD47-SIRPα axis.

02

Conditions studied

  • Solid Tumor

Keywords

  • mAB
  • Monoclonal antibody
  • SIRPα
  • CD47
  • SIRP
03

Who can participate

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

Inclusion criteria

  • Patient with histologically confirmed, locally advanced or metastatic cancer who has progressed on standard therapy or for whom no standard therapy exists:

    • Part 1 (dose escalation): Solid tumors of any origin;
    • Part 2 (expansion): Patients with other solid tumor types indicated for pembrolizumab monotherapy;
  • Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1;
  • For Part 2 only: at least one measurable cancer lesion as defined by the Response Evaluation Criteria for Solid Tumors (RECIST version 1.1);
  • Adequate baseline organ function.

Exclusion criteria

Exclusion Criteria:

  • Having been treated with CD47 or SIRPα targeting agents or other anticancer therapy within 4 weeks prior to the start of IMP treatment;
  • History of hypersensitivity or allergic reaction to any of the excipients of BYON4228;
  • Any contraindication to pembrolizumab treatment;
  • For Part 2: Patients previously given a PD-1 or PD-L1 inhibitor who had subsequent disease progression within 8 weeks of initiation;
  • Symptomatic brain metastases;
  • History of autoimmune disorders;
  • Severe active infection or other severe uncontrolled systemic 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.

04

Study design

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

Study arms

  • Experimental
    BYON4228 + Pembrolizumab

    Drug: BYON4228 + Pembrolizumab

Interventions

  • DrugBYON4228 + Pembrolizumab

    BYON4228 is a humanized monoclonal antibody (mAb) directed against SIRPα. BYON4228 IV infusion every three weeks until disease progression or unacceptable toxicity. Different doses. Pembrolizumab IV infusion (200 mg) every three weeks from the second treatment cycle onwards.

05

What researchers measure

Primary outcomes

  1. Incidence of Dose-Limiting Toxicities

    Time frame: 21 days

  2. Objective Response Rate

    Part 2 (expansion): To evaluate the objective tumor response rate (ORR).

    Time frame: 2 years

06

Study locations

6 sites
  • Institut Jules Bordet
    Brussels, Belgium
  • UZ Leuven
    Leuven, Belgium
  • CIOCC Hospital Universitario HM Sanchinarro
    Madrid, Spain
  • Hospital Universitario Fundación Jiménez Díaz
    Madrid, Spain
  • The Christie NHS Foundation Trust
    Manchester, United Kingdom
  • The Royal Marsden
    Sutton, United Kingdom
07

Registry details

Key details

Study ID
NCT06932952
Lead sponsor
Byondis B.V.
Responsible party
Sponsor
First posted
Apr 17, 2025
Start date
May 7, 2025
Primary completion
Apr 2026 (estimated)
Completion
Dec 2026 (estimated)
Last update
Jan 16, 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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