A Study of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumors (MK-9999-01C/LIGHTBEAM-U01)

Launched by MERCK SHARP & DOHME LLC · Apr 15, 2025

Keywords

ClinConnect Summary

This clinical trial is studying a new treatment called HER3-DXd (also known as patritumab deruxtecan) for children with specific types of cancer: hepatoblastoma, a liver cancer commonly found in babies and young children, and rhabdomyosarcoma (RMS), which is a cancer that affects muscle cells. The trial is looking for children whose cancer has either come back after treatment (relapsed) or did not respond to previous treatments (refractory). The main goals of the study are to learn how safe HER3-DXd is for children, how their bodies handle the treatment, and if it helps shrink or eliminate the cancer.

To participate in this study, children need to have a confirmed diagnosis of either RMS or hepatoblastoma and must have already received at least one other treatment that didn’t work well for them. They should not have other ongoing health issues that could complicate their participation. The study is not yet recruiting participants, but when it does, children will receive the treatment under careful supervision, and their health will be monitored closely throughout the trial. Overall, this study aims to find out if HER3-DXd can be a new option for children with these challenging cancers.

Gender

ALL

Eligibility criteria

• The main inclusion criteria include but are not limited to the following:
• • Has one of the following histologically confirmed advanced or metastatic solid tumors: Rhabdomyosarcoma (RMS), or Hepatoblastoma
• • Has progressed after at least 1 prior systemic treatment for RMS or hepatoblastoma and who has no satisfactory alternative treatment option (ie, is ineligible for other standard treatment regimens)
• • Participants who have adverse events (AEs) due to previous anticancer therapies must have recovered to Grade ≤1 or baseline. Participants with endocrine-related AEs who are adequately treated with hormone replacement or participants who have Grade ≤2 neuropathy are eligible
• • Hepatitis B surface antigen (HBsAg) positive participants are eligible if they have received hepatitis B virus (HBV) antiviral therapy and have undetectable HBV viral load
• • Participants with a history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable
• The main exclusion criteria include but are not limited to the following:
• • Has a history of (noninfectious) interstitial lung disease (ILD)/pneumonitis that required steroids or has current ILD/pneumonitis, and/or suspected ILD/pneumonitis that cannot be ruled out by standard diagnostic assessments
• • Has clinically severe respiratory compromise resulting from intercurrent pulmonary illness
• • Has a history of solid organ transplant
• • Has a history of allogeneic stem cell transplant
• • Has clinically significant corneal disease
• • Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis/leptomeningeal disease; participants with previously treated brain metastases may participate provided they are radiologically stable (ie, without evidence of progression) for at least 4 weeks
• • Has uncontrolled or significant cardiovascular disorder
• • Has a history of clinically significant congenital cardiac syndrome
• • Has a history of human immunodeficiency virus (HIV) infection
• • Has a known additional malignancy that is progressing or has required active treatment within the past 1 year
• • Has an active infection requiring systemic therapy
• • Has concurrent active hepatitis B (HBsAg positive and/or detectable HBV deoxyribonucleic acid \[DNA\]) and HCV defined as anti-HCV antibody (Ab) positive and detectable HCV ribonucleic acid \[RNA\]) infection
• • Has not adequately recovered from major surgery or have ongoing surgical complications