Clinical trial · Interventional
A Study of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumors (MK-9999-01C/LIGHTBEAM-U01)
LIGHTBEAM-U01 Substudy 01C: A Phase 1/2 Substudy to Evaluate the Safety and Efficacy of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumors
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 18, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260918-000001
Summary
Brief summary (as posted)
Researchers are looking for new ways to treat children with hepatoblastoma or rhabdomyosarcoma (RMS) that has relapsed or is refractory: * Hepatoblastoma is a common liver cancer in babies and very young children * RMS is a cancer that starts in muscle cells, often in a child's head and neck, bladder, arms, or legs * Relapsed means the cancer came back after treatment * Refractory means the cancer did not respond (get smaller or go away) to treatment The study treatment HER3-DXd (also known as MK-1022 or patritumab deruxtecan) is an antibody-drug conjugate (ADC). An ADC attaches to a protein on cancer cells and delivers treatment to destroy those cells. The goals of this study are to learn: * About the safety of HER3-DXd in children and if they tolerate it * What happens to HER3-DXd in children's bodies over time * If children who receive HER3-DXd have the cancer get smaller or go away
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Malignant Neoplasm | Malignant Neoplasm | ONTOLOGY_EXACT | 0.90 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Patritumab Deruxtecan | Biological | Patritumab Deruxtecan | ALIAS |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Patritumab Deruxtecan
- description
- Participants receive patritumab deruxtecan via IV infusion on Day 1 of each 3-week cycle until discontinuation or progression.
- interventionNames
- Biological: Patritumab Deruxtecan
Primary outcomes (13)
- measure
- Part 1: Percentage of Participants Who Experience Dose-limiting Toxicities (DLTs)
- timeFrame
- Cycle 1 (up to approximately 21 days); each cycle is 21 days
- description
- A DLT is any of a prespecified list of adverse events (AEs) that occur during Cycle 1 (up to 21 days) if attributed to the study treatment and not attributed to any other clearly identifiable cause. The percentage of participants who experience DLTs will be reported. Each cycle is 21 days.
- measure
- Part 1: Percentage of Participants Who Experience an Adverse Event (AE)
- timeFrame
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 1 Month
- Maximum age
- 17 Years
Show eligibility criteria text
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. Participants with Grade ≤2 alopecia are also 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 interstitial lung disease (ILD)/pneumonitis irrespective of steroid use, or current ILD/pneumonitis, or suspected ILD/pneumonitis, or ILD that cannot be ruled out by imaging * 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
References
Publications (0)
Data not yet available