Vepdegestrant (ARV-471/PF-07850327) + Palbociclib vs Letrozole + Palbociclib in ER(+)/HER2(-) Advanced Breast Cancer

Running, not enrolling · Phase 3

Conditions studied: Breast Cancer

In brief

The purpose of this study is to understand the safety and effects of the study medicine vepdegestrant (ARV-471/PF-07850327) given together with palbociclib in advanced breast cancer. In particular, the study will compare the combination of vepdegestrant plus palbociclib to standard of care therapy (letrozole plus palbociclib). Both letrozole and palbociclib are medicines already used for treatment of breast cancer. Vepdegestrant is a new medicine under study. This study is seeking participants who have breast cancer that: * Have a locally advanced or metastatic disease and cannot be fully cured by surgery or radiation therapy. A metastatic disease is when disease has spread to other parts of the body. * Is sensitive to hormonal therapy such as tamoxifen. This is called estrogen receptor positive disease. * Have not received any prior medicine for advanced disease. Example medications include tamoxifen or letrozole or exemestane. The study will have an open-label SLI (study lead-in) before initiation of Phase 3 trial. During SLI, two dose levels of palbociclib in combination with vepdegestrant will be explored in parallel. Assignment to the palbociclib dose is by chance. Half of the participant will receive one dose and the other half another palbociclib dose. The purpose of SLI is to determine the recommended Phase 3 dose of palbociclib to be administered in combination with vepdegestrant. In the Phase 3, half of the participants will take vepdegestrant plus palbociclib while the other half will take letrozole plus palbociclib. In both SLI and Phase 3, participants will take the study medicines by mouth, with food, once a day. Participants will take the study medicines until breast cancer increase in size or side effects become too severe. Side effects refer to unwanted reactions to medications. Participants will visit the study clinic about once every 4 weeks.

Key facts

Study ID

NCT05909397

Run by

Pfizer

People needed

59

Starts

2023-08-09

Expected to finish

2026-12-30

Last updated by the study team

2026-02-10

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Adult participants with loco-regional recurrent or metastatic disease not amenable to curative treatment
• Confirmed diagnosis of ER+/HER2- breast cancer
• No prior systemic treatment for loco-regional recurrent or metastatic disease
• Measurable disease evaluable per Response Evaluation Criterion in Solid Tumors (RECIST) v.1.1 or non-measurable bone-only disease
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2
• Phase 3 only: Participants should be willing to provide blood and tumor tissue

You may not qualify if…

• Disease recurrence while on, or within 12 months of completion of adjuvant endocrine therapy
• Prior treatment with cyclin dependent kinase 4/6 inhibitors (CDK4/6i), vepdegestrant, fulvestrant, elacestrant and other investigational drugs including novel endocrine therapies, any selective estrogen receptor degraders (SERDs), covalent antagonists (SERCAs) and complete ER antagonists (CERANs).
• Inadequate liver, kidney and bone marrow function
• Impaired cardiovascular function or clinically significant cardiovascular diseases
• Refractory nausea and vomiting, inability to swallow capsules and tablets whole, chronic gastrointestinal diseases, significant gastric (total or partial) or bowel resection that would preclude adequate absorption of study interventions.
• Current use or anticipated need for food, herbal supplements or drugs that are known strong CYP3A4 inhibitors or inducers.

Where it is running

• Istituto Nazionale Tumori IRCCS Fondazione Pascale — Naples, Campania, Italy
• BRCR Global — Plantation, Florida, United States
• BRCR Medical Center Inc — Plantation, Florida, United States
• Virginia Oncology Associates — Norfolk, Virginia, United States
• Cancer Research SA — Adelaide, South Australia, Australia
• Barwon Health — Geelong, Victoria, Australia
• Hospital Santa Rita de Cassia — Vitória, Espírito Santo, Brazil
• Centro Gaucho Integrado De Oncologia, Hematologia, Ensino E Pesquisa — Porto Alegre, Rio Grande do Sul, Brazil
• Centro de Pesquisa Clínica - Área Administrativa — Porto Alegre, Rio Grande do Sul, Brazil
• Hospital Mae de Deus — Porto Alegre, Rio Grande do Sul, Brazil
• Cancer Hospital Chinese Academy of Medical Science — Beijing, Beijing Municipality, China
• Sun Yat-sen University Cancer Center — Guangzhou, Guangdong, China
• Hubei Cancer Hospital — Wuhan, Hubei, China
• The First Affiliated Hospital of Xi'an Jiaotong University — Xi'an, Shaanxi, China
• Debreceni Egyetem Klinikai Kozpont — Debrecen, Hungary
• IRCCS - Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori" — Meldola, Emilia-Romagna, Italy
• Fondazione IRCCS San Gerardo dei Tintori — Monza, Lombardy, Italy
• Aichi Cancer Center Hospital — Nagoya, Aichi-ken, Japan
• National Cancer Center Hospital East — Kashiwa, Chiba, Japan
• National Cancer Center Hospital — Chuo-ku, Tokyo, Japan
• Nemocnica na okraji mesta n o — Partizánske, Slovakia
• Fakultna nemocnica s poliklinikou J.A. Reimana Presov — Prešov, Slovakia
• Institut Català d'Oncologia (ICO) - Badalona — Badalona, Barcelona [barcelona], Spain
• Hospital Universitari Dexeus — Barcelona, Catalunya [cataluña], Spain
• Complejo Hospitalario de Jaén — Jaén, JAÉN, Spain

Full record on ClinicalTrials.gov

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