Extension program for people previously treated with belzutifan (MK-6482)

A Multicenter, Open-label, Phase 3 Extension Study to Evaluate the Long-term Efficacy and Safety in Participants Who Are Currently on Treatment in a Belzutifan Study (LITESPARK-043)

Phase 3 Interventional Merck Sharp & Dohme LLC · NCT07405164

This extension lets people with advanced solid tumors or VHL-related tumors who were already taking belzutifan in another study continue the drug so researchers can see how long they live and watch for long-term effects.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment450 (estimated)
Ages18 Years and up
SexAll
SponsorMerck Sharp & Dohme LLC Industry-sponsored
Locations11 sites (San Antonio, Texas and 10 other locations)
Trial IDNCT07405164 on ClinicalTrials.gov

What this trial studies

This open-label extension enrolls participants who received belzutifan in qualifying parent trials to continue active treatment and long-term follow-up. The program collects safety data, duration of drug exposure, and survival outcomes while monitoring adverse events over time. Enrollment is limited to patients who are clinically stable or have resumed treatment after a temporary interruption in their parent study. The trial is sponsored by Merck and conducted at selected sites in the United States and Israel.

Who should consider this trial

Good fit: Ideal candidates are people with advanced solid tumors or VHL-related neoplasms who are already receiving belzutifan in an eligible parent study and are clinically stable or have restarted treatment after an interruption.

Not a fit: Patients who were not enrolled in a belzutifan parent trial, who have ongoing serious adverse events, or who remain hospitalized or clinically unstable are unlikely to be eligible or to benefit from this extension.

Why it matters

Potential benefit: If successful, the extension could clarify how durable belzutifan's benefits are and provide safety information that helps guide longer-term use for patients with VHL-related tumors and advanced solid cancers.

How similar studies have performed: Prior belzutifan trials have shown clinical activity in VHL-associated tumors and advanced renal cell carcinoma, supporting this extension for long-term safety and survival follow-up.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

* Participants with advanced solid tumors or von Hippel-Lindau-related neoplasms who are participating in belzutifan-containing studies and on active treatment in a belzutifan parent study.

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

* Has an on-going serious adverse event in the parent study, unless no longer hospitalized and considered clinically stable.
* Is currently on a dose interruption due to an Adverse Event (AE) in the parent study; once treatment has been resumed in the parent study, the participant is eligible to enroll.

Where this trial is running

San Antonio, Texas and 10 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Von Hippel-Lindau DiseaseCarcinoma, Renal Cell
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.