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Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029) | Clinical Trials | Clareo Health

RECRUITINGPHASE2

Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)

A Phase 2, Randomized, Active-controlled, Open-label, Multicenter Study of Belzutifan Plus Fulvestrant in Participants With Estrogen Receptor Positive, HER2 Negative Unresectable Locally Advanced or Metastic Breast Cancer After Progression on Previous Endocrine Therapy (LITESPARK-029)

NCT06428396•Merck Sharp & Dohme LLC

View on ClinicalTrials.gov

Summary

The purpose of this study is to assess the efficacy and safety of belzutifan (MK-6482) plus fulvestrant compared to everolimus plus endocrine therapy (ET) (investigator's choice of fulvestrant or exemestane) in adults with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) unresectable metastatic breast cancer. There is no formal hypothesis testing in this study.

Eligibility

Age

18 - No limit years

Sex

ALL

Healthy Volunteers

Inclusion Criteria

•Has a diagnosis of estrogen receptor positive (ER+)/human epidermal growth factor receptor negative (HER2-) invasive breast carcinoma that is either locally advanced disease not amenable to resection or metastatic disease not treatable with curative intent
•Has documented radiographic confirmation of disease progression during or after the last administered endocrine therapy (ET)
•Provides additional tissue from the same sample used to determine ER and HER2 status locally
•Has received ET in the noncurative setting and has 1) Radiographic disease progression on 12 months or more of ET in combination with CDK4/6 inhibitor in the noncurative setting or 2) Received at least 2 lines of ET in the noncurative setting including CDK4/6 inhibitor where the CDK 4/6 inhibitor was discontinued due to intolerance
•Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 assessed within 7 days of randomization
•Participants who have 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

Exclusion Criteria

•Has Breast cancer amenable to treatment with curative intent
•Is unable to receive any of the endocrine therapies (ETs) (ie, fulvestrant or exemestane)
•Has known difficulty in tolerating oral medications, unable to swallow orally administered medication, or conditions which would impair absorption of oral medications such as uncontrolled nausea or vomiting (ie, CTCAE =Grade 3 despite antiemetic therapy), ongoing gastrointestinal obstruction, motility disorder, malabsorption syndrome, or prior gastric bypass
•Has advanced/metastatic, symptomatic visceral spread at risk of rapidly evolving into life-threatening complications
•Has active, bleeding diathesis, or on oral anti-vitamin K medication
•Has history of noninfectious pneumonitis/interstitial lung disease including radiation pneumonitis that required steroids or has current pneumonitis/interstitial lung disease
•Has a known germline BRCA mutation (deleterious or suspected deleterious) and has received previous treatment with poly-ADP ribose polymerase (PARP) inhibition either in the adjuvant or metastatic setting
•Has received prior fulvestrant in the adjuvant, unresectable locally advanced, or metastatic setting
•Has received any line of cytotoxic chemotherapy or PARP inhibitor in the unresectable or noncurative advanced/metastatic setting
•Has received prior radiotherapy for non-central nervous system (CNS) disease or required corticosteroids for radiation-related toxicities including radiation pneumonitis, within 14 days of the first dose of study intervention
+6 more criteria

Locations (41)

City of Hope - Phoenix ( Site 0006)

Goodyear, Arizona, United States

Cedars Sinai Medical Center ( Site 0012)

Beverly Hills, California, United States

Moores Cancer Center at UC San Diego Health ( Site 0025)

La Jolla, California, United States

USC/Norris Comprehensive Cancer Center ( Site 0013)

Los Angeles, California, United States

USC Norris Oncology Hematology Newport Beach ( Site 0029)

Newport Beach, California, United States

Northwest Georgia Oncology Centers, a Service of Wellstar Cobb Hospital ( Site 0011)

Marietta, Georgia, United States

Southeastern Regional Medical Center ( Site 0010)

Newnan, Georgia, United States

CHRISTUS Highland ( Site 0005)

Shreveport, Louisiana, United States

Renown Regional Medical Center ( Site 0018)

Reno, Nevada, United States

MD Anderson Cancer Center at Cooper ( Site 0024)

Camden, New Jersey, United States

Key Dates

Start Date

November 27, 2024

Primary Completion Date

May 5, 2027

Completion Date

October 7, 2028

Last Updated

December 26, 2025

Enrollment

120

ESTIMATED participants

Conditions

Metastatic Breast Cancer

Interventions

Belzutifan

DRUG

Fulvestrant

DRUG

Everolimus

DRUG

Exemestane

DRUG

Contacts

Toll Free Number

CONTACT

1-888-577-8839 Trialsites@msd.com

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Solid Tumor, AdultMetastatic Breast Cancer+9 more

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Data Source & Attribution

This clinical trial information is sourced from ClinicalTrials.gov, a service of the U.S. National Institutes of Health.

ClinicalTrials.gov last update: December 26, 2025Data synced to Clareo: March 29, 2026

Modifications: This data has been reformatted for display purposes. Eligibility criteria have been parsed into inclusion/exclusion sections. Location data has been geocoded to enable distance-based search. For the authoritative and most current information, please visit ClinicalTrials.gov.

Neither the United States Government nor Clareo Health make any warranties regarding the data. Check ClinicalTrials.gov frequently for updates.

View ClinicalTrials.gov Terms and Conditions

Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)

Inclusion Criteria

Exclusion Criteria

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