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NCT Number: NCT05909397

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 (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.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Breast Cancer Breast Diseases Breast Neoplasms Neoplasms Neoplasms by Site Skin Diseases Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Cancer Research SA, Adelaide, South Australia, Australia

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About this study

The purpose of this study is to demonstrate that vepdegestrant (ARV-471) in combination with palbociclib provides superior clinical benefit compared to letrozole in combination with palbociclib in participants with ER(+)/HER2(-) aBC who have not received any prior systemic anti-cancer therapies for their locoregionally advanced or metastatic disease.

The study will have a Study Lead-in (SLI) and a Phase 3. In the SLI, 50 participants (approximately 25 each arm) will be randomly assigned on a 1:1 basis to one of the two dose levels (DLs). In the randomized Phase 3, approximately 1130 eligible participants (approximately 565 each arm) will be randomized in a 1:1 ratio to the Experimental Arm (ie, vepdegestrant plus palbociclib at RP3D determined in the SLI) or Control Arm (ie, letrozole plus palbociclib at the registered doses). Randomization will be stratified by menopausal status at study entry, visceral disease and de novo metastatic disease.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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.

Treatment and study plan

Vepdegestrant (ARV-471/PF-07850327)

Drug

Pharmaceutical form: Tablets. Route of Administration: Oral

Other names: Vepdegestrant

Palbociclib

Combination Product

Pharmaceutical form: Capsules. Route of Administration: Oral.

Other names: IBRANCE®

letrozole

Drug

Pharmaceutical form: Capsules. Route of Administration: Orally

Other names: FEMARA®

Primary outcomes

  1. Study Lead-in (SLI): Incidence of Grade 4 neutropenia

    Time frame: From randomization date up to Cycle 4 (each cycle is 28 days).

    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.

  2. SLI: Incidence of dose reduction

    Time frame: From randomization date up to Cycle 4 (each cycle is 28 days).

    It is defined as the number of participants reducing the dose of palbociclib and/or vepdegestrant due to any cause occurring within the first 4 cycles divided by the number of participants.

  3. SLI: Incidence of drug discontinuation.

    Time frame: From randomization date up to Cycle 4 (each cycle is 28 days).

    It is defined as the number of participants discontinuing palbociclib and/or vepdegestrant due to any cause occurring within the first 4 cycles divided by the number of participants.

  4. Phase 3: Progression-Free Survival

    Time frame: From randomization date, every 12 weeks, to date of first documentation of progression or death, up to approximately 4 years.

    Progression-free survival is defined as the time interval from the date of randomization to the date of first documented tumor progression determined by Blinded Independent Central Review (BICR) as per Response Evaluation Criteria in Solid Tumors (RECIST version 1.1) or death due to any cause, whichever come first.

Secondary outcomes

  1. SLI and Phase 3. Objective Response Rate

    Time frame: From randomization date, every 12 weeks, to the date of progression or death (up to approximately 4 years).

    Objective response rate is defined as the proportion of participants who have a confirmed CR or PR, as best overall response determined by Investigators (SLI) or by BICR (Phase 3) as per RECIST version 1.1, from the date of randomization to the date of disease progression or death due to any cause, whichever occurs first.

  2. SLI and Phase 3: Duration of Response

    Time frame: From the date of the first objective response, every 12 weeks, to the date of disease progression or death (up to approximately 4 years).

    Duration of response is defined as the time from first documented evidence of CR or PR until progressive disease (PD) determined by Investigators (SLI) or by BICR (Phase 3) as per RECIST version 1.1 or death due to any cause, whichever occurs first.

  3. SLI and Phase 3: Clinical Benefit Rate

    Time frame: Every 12 weeks From randomization date, every 12 week, to the date of progression or death (up to approximately 4 years).

    Clinical benefit rate is defined as the proportion of participants who have a confirmed CR, PR at any time or SD or non CR/non PD for at least 24 weeks determined by Investigators (SLI) or by BICR (Phase 3) as per RECIST version 1.1, from the date of randomization until disease progression or death due to any cause, whichever occurs first.

  4. Phase 3: Overall Survival

    Time frame: From randomization date, every 3 months, to date of death (up to approximately 6 years)

    Overall survival is defined as the time interval from the date of randomization to the date of documented death, due to any cause.

  5. SLI and Phase 3: Incidence of Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)

    Time frame: From baseline to date to end of treatment (up to approximately 4 years)

    It is defined as the number of participants with TEAEs and SAEs divided by the number of participants. AEs and SAEs will be graded according to NCI CTCAE V5.0.

  6. SLI and Phase 3: Incidence of laboratory abnormalities

    Time frame: From baseline to end of treatment (up to approximately 4 years)

    It is defined as the number of participants with laboratory abnormalities divided by the number of participants. Laboratory abnormalities will be graded according to NCI CTCAE V5.0.

  7. SLI and Phase 3: Incidence of Electrocardiogram (ECG) Abnormalities

    Time frame: From baseline up to the end of treatment (up to approximately 4 years)

    It is defined as the number of participants with ECG abnormalities divided by the number of participants. ECG abnormalities will be graded according to NCI CTCAE V5.0.

  8. SLI and Phase 3: Plasma concentrations of vepdegestrant and palbociclib

    Time frame: From randomization date up to Cycle 5 (each cycle is 28 days)

    Plasma concentrations of vepdegestrant and palbociclib

  9. Phase 3: Health state utility and health status will be assessed using the European Quality of Life Group questionnaire with 5 dimensions and 5 levels per dimension (EQ-5D-5L)

    Time frame: From baseline, each cycle up to cycle 3, then every odd cycle to end of treatment (up to approximately 4 years). Each cycle is 28 days

    Change from baseline between treatment comparison in Quality of Life using the EQ-5D 5L questionnaire.

  10. Phase 3: Disease-related Quality of Life will be assessed using the European Organization for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30)

    Time frame: From baseline, each cycle up to Cycle 3, then every odd cycle to end of treatment (up to approximately 4 years). Each cycle is 28 days.

    Change from baseline between treatment comparison in Quality of Life using the EORTC QLQ-C30 questionnaire.

  11. Phase 3: Disease- and treatment-related Quality of Life will be assessed using the European Organization for Research and Treatment of Cancer (EORTC) breast cancer module (QLQ-BR23) questionnaire.

    Time frame: From baseline, each cycle up to Cycle 3, then every odd cycle to end of treatment (up to approximately 4 years). Each cycle is 28 days.

    Change from baseline between treatment comparison in Quality of Life Using the EORTC QLQ-BR23 (Breast) questionnaire.

  12. Phase 3: Changes from baseline in plasma ctDNA (Circulating Deoxyribonucleic Acid)

    Time frame: From baseline to end of treatment (up to approximately 4 years)

    Quantitative changes from baseline

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Collaborators

  • Arvinas Estrogen Receptor, Inc.

Registry information

Official study title

A PHASE 3, RANDOMIZED, OPEN-LABEL, MULTICENTER STUDY OF VEPDEGESTRANT (ARV-471/PF-07850327) PLUS PALBOCICLIB VERSUS LETROZOLE PLUS PALBOCICLIB FOR THE TREATMENT OF PARTICIPANTS WITH ESTROGEN RECEPTOR POSITIVE, HER2 NEGATIVE BREAST CANCER WHO HAVE NOT RECEIVED ANY PRIOR SYSTEMIC ANTI CANCER TREATMENT FOR ADVANCED DISEASE (VERITAC-3)

Acronym: VERITAC-3

Important dates

Study start
2023
Primary completion
2026
Study completion
2026
First posted
Jun 18, 2023
Registry last updated
Feb 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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