A Study of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumo… (NCT06941272) | Clinical Trial Compass
RecruitingPhase 1/2
A Study of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumors (MK-9999-01C/LIGHTBEAM-U01)
United States, Australia, Belgium50 participantsStarted 2025-05-26
Plain-language summary
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
Who can participate
Age range
1 Month – 17 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
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 (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 c…
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Part 1: Percentage of Participants Who Experience Dose-limiting Toxicities (DLTs)
Timeframe: Cycle 1 (up to approximately 21 days); each cycle is 21 days
2
Part 1: Percentage of Participants Who Experience an Adverse Event (AE)
Timeframe: Up to approximately 5 years
3
Part 1: Percentage of Participants Who Discontinue Study Treatment Due to an AE
Timeframe: Up to approximately 5 years
4
Part 1: Area Under the Curve (AUC) of total anti-HER3 antibody liquid chromatography-mass spectrometry (LC-MS) in plasma
Timeframe: At designated timepoints (up to approximately 5 years)
5
Part 1: AUC of anti-HER3 antibody-conjugated DXd (anti-HER3-ac-DXd) in plasma
Timeframe: At designated timepoints (up to approximately 5 years)
6
Part 1: AUC of DXd in plasma
Timeframe: At designated timepoints (up to approximately 5 years)
7
Part 1: Maximum Concentration (Cmax) of anti-HER3 antibody LC-MS in plasma