MK9999-01A

Clinical study into zilovertamab vedotin for the treatment of children with hematological malignancies or solid tumors. In the Netherlands the study is only open for children or adolescents with bone tumors.

Recruiting

Who can participate

Children and adolescents with bone tumors who did not respond to treatment or for whom no treatment is available
Age: 6 months to 18 years

Goal

In this study, zilovertamab vedotin is being used. Zilovertamab vedotin is still under investigation, and cannot be prescribed by doctors (outside of studies). It is therefore called an investigational drug. Zilovertamab vedotin is also called MK2140.

This is the first study to test zilovertamab vedotin in children. The goals of this study are:

To see how safe the investigational drug is
To see how well the investigational drug works and how long it works
To test the investigational drug in different doses in patients with blood cancers and solid tumors
To explore what zilovertamab vedotin does in the body

Background

There is still a need for more research into the treatment of bone cancer in children and adolescents. The investigational drug zilovertamab vedotin can find certain proteins that are present on cancer cells. This allows the investigational drug to attach to these cells and kill them. The investigational drug is being investigated by the sponsor for different types of tumors.

In order to participate in a study please refer to your/your child’s doctor.

Last reviewed

March 23, 2026

Study details
Official title
LIGHTBEAM-U01-Substudy 01A: A Phase 1/2 Substudy to Evaluate the Safety and Efficacy of Zilovertamab Vedotin in Pediatric and Young Adult Participants with Hematologic Malignancies or Solid Tumors.
Cancer type
Bone tumors
Phase
1/2
Maximum number of patients
50-90, of whom 3 are expected to participate in the Netherlands
Start date
May 14, 2025
Status
Open for inclusion
Local principal investigator
Dr. N.K.A van Eijkelenburg
Sponsor
Merck, Sharp & Dohme
Approval
The study of this new treatment has been reviewed by an accredited medical research ethics committee. This committee has decided that it is justified to ask patients to participate in this study. More information can be found at: CCMO.
Trial registry number
EU clinical trials: 2023-507178-41
After completion of the study, you will find a summary of the results in plain language on the EU website. You can find the study by searching for MK9999-01A or 2023-507178-41.