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NCT05909397 · ClinicalTrials.gov registry record · Phase 3

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

A Phase 3 study of Breast Cancer, sponsored by Pfizer.

Active
Registry status
Phase 3
Development phase
59
Enrollment target
20
Study locations

NCT05909397: Active Phase 3 study of Breast Cancer, sponsored by Pfizer.

NCT05909397 is a Phase 3 study of Breast Cancer that is active but no longer recruiting, run by Pfizer. The registered enrollment target is 59 participants, below the 2,803-participant average among 1,224 other Breast Cancer trials with a reported enrollment target (98% lower). The trial reports 20 study locations across 17 states. According to ClinicalTrials.gov, the official US trial registry.

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The verdict

NCT05909397, a Phase 3 study of Breast Cancer, is active but no longer recruiting, sponsored by Pfizer.

ACTIVE NOT RECRUITING
Registry status
Phase 3
Development phase
59 participants
Enrollment target
20
Study locations

Study Summary

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.

Primary Outcome

It is defined as the number of participants with Grade 4 neutropenia AE (graded by NCI CTCAE v.5.0) with onset within the first 4 cycles divided by the number of participants.

Conditions Studied

Interventions

  • DRUG Letrozole
  • DRUG Vepdegestrant (ARV-471/PF-07850327)
  • COMBINATION_PRODUCT Palbociclib

Study Locations (20)

Rio Grande do Sul

  • Centro Gaucho Integrado De Oncologia, Hematologia, Ensino E Pesquisa - Porto Alegre
  • Centro de Pesquisa Clínica - Área Administrativa - Porto Alegre
  • Hospital Mae de Deus - Porto Alegre

Florida

  • BRCR Global - Plantation
  • BRCR Medical Center Inc - Plantation

Virginia

  • Virginia Oncology Associates - Norfolk

South Australia

  • Cancer Research SA - Adelaide

Victoria

  • Barwon Health - Geelong

Espírito Santo

  • Hospital Santa Rita de Cassia - Vitória

Beijing Municipality

  • Cancer Hospital Chinese Academy of Medical Science - Beijing

Guangdong

  • Sun Yat-sen University Cancer Center - Guangzhou

Trial Details

FieldValue
Enrollment Target 59 participants
Start Date 2023-08-09
Est. Completion 2026-12-30
Phase Phase 3
Pfizer

1,845 total trials

What the registry record for NCT05909397 still lists

NCT05909397 is an interventional study that assigns participants to a tested intervention. The registry caps enrollment at 59 participants, a relatively small participant target, below the 2,803-participant average among 1,224 other Breast Cancer trials with a reported enrollment target (98% lower).

The record links to 1 condition, with Breast Cancer appearing as the primary indexed condition, and to 3 interventions - of which Letrozole is the first listed.

NCT05909397 names 20 study sites across 17 states, led by Rio Grande do Sul, Florida, Virginia.

Frequently Asked Questions

What is clinical trial NCT05909397 about?

NCT05909397 is a clinical study titled "Vepdegestrant (ARV-471/PF-07850327) + Palbociclib vs Letrozole + Palbociclib in ER(+)/HER2(-) Advanced Breast Cancer". 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 (...

What is the current status of trial NCT05909397?

This trial is currently active not recruiting. It is a Phase 3 study. The enrollment target is 59 participants. The study started on 2023-08-09. Estimated completion is 2026-12-30.

What conditions does trial NCT05909397 study?

This clinical trial studies the following conditions: Breast Cancer.

What interventions are being tested in trial NCT05909397?

The interventions under investigation include: Letrozole (DRUG), Vepdegestrant (ARV-471/PF-07850327) (DRUG), Palbociclib (COMBINATION_PRODUCT).

Who is sponsoring clinical trial NCT05909397?

This trial is sponsored by Pfizer, which has 1,845 total clinical trials registered on ClinicalTrials.gov.

Where is trial NCT05909397 being conducted?

This trial has 20 study locations across Florida, Virginia, South Australia, Victoria, Espírito Santo. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.

Similar trials for Breast Cancer

Matched on the same primary condition, ranked to surface studies in the same phase first, then by recruiting status, no relevance scoring or editorial curation.

Where NCT05909397's enrollment target sits among peer trials

59 758th of 1224 higher than 465 of 1,224 other Breast Cancer trials

participants (enrollment target), bucketed by value

Each bar is a band; taller bars hold more other Breast Cancer trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source ClinicalTrials.gov registry export · 2026-08-08

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Source: ClinicalTrials.gov NCT05909397, the US trial registry maintained by the National Library of Medicine. NCT05909397 (small enrollment · wide site footprint · active not recruiting) retrieved and formatted by PlainTrial, see methodology.