A Study of Belzutifan in Adolescent Participants With Solid Tumors (MK-9999-01E/LIGHTBEAM-U01) (NCT07700758) | Clinical Trial Compass
Not Yet RecruitingPhase 2
A Study of Belzutifan in Adolescent Participants With Solid Tumors (MK-9999-01E/LIGHTBEAM-U01)
15 participantsStarted 2026-11-23
Plain-language summary
Researchers are looking for new ways to treat adolescents with locally advanced, unresectable, or metastatic solid tumors. Participants were enrolled into pheochromocytoma/paraganglioma (PPGL), wild type gastrointestinal stromal tumor (wtGIST), and Von Hippel-Lindau (VHL) disease-associated localized tumors cohorts:
* PPGL are rare cancers that start in cells that make hormones in the adrenal glands
* wtGIST is a less common type of cancer that starts in the digestive tract. Wild type means it does not have certain gene mutations (changes)
* VHL disease-associated localized tumors are rare tumors caused by a certain gene mutation that may be passed down from parents to children
* Locally advanced means the cancer has spread into nearby tissue
* Unresectable means the cancer cannot be removed by surgery
* Metastatic means the cancer has spread to other parts of the body
The goal of the study is to learn about the safety of belzutifan and if people tolerate it.
Who can participate
Age range
12 Years – 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.
Inclusion Criteria:
The main inclusion criteria include but are not limited to the following:
* Has a diagnosis of one of the following: locally advanced, unresectable, or metastatic pheochromocytoma/paraganglioma or wild-type gastrointestinal stromal tumors, or localized tumors associated with von Hippel-Lindau disease
* Has measurable disease per RECIST 1.1
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
* Has a pulse oximeter reading \<92% at rest, requires intermittent supplemental oxygen, or requires chronic supplemental oxygen
* Has clinically significant cardiac disease or electrocardiogram indicating uncontrolled cardiac condition or has congenital long QT syndrome
* Has a history of human immunodeficiency virus infection
* Has received prior treatment with any hypoxia inducible factor-2α inhibitor, including belzutifan
* Has had an allogenic tissue/solid organ transplant
* Has a history of autologous stem cell transplant within 6 months of start of study intervention
* Has known additional malignancy that is progressing or has required active treatment within the past 2 years
* Has known active central nervous system metastases and/or carcinomatous meningitis
* Has an active infection requiring systemic therapy
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
Number of Participants Who Experience One or More Adverse Events (AEs)
Timeframe: Up to approximately 5 years
2
Number of Participants Who Discontinue Study Intervention Due to an AE