ARV-471 in Combination With Everolimus for the Treatment of Advanced or Metastatic ER+, HER2- Breast Cancer (TACTIVE-E)

September 23, 2025 updated by: Arvinas Estrogen Receptor, Inc.

A Phase 1b Trial of ARV-471 in Combination With Everolimus in Patients With ER+, HER2- Advanced or Metastatic Breast Cancer

A phase 1b study to assess the combination of ARV-471 and everolimus in participants with advanced or metastatic ER+/HER2- breast cancer.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a Phase 1b study to assess the safety and tolerability of ARV-471 in combination with everolimus in participants with estrogen receptor positive/human epidermal growth factor receptor 2 negative (ER+/HER2-) advanced or metastatic breast cancer, who have received a prior CDK4/6 inhibitor and endocrine therapy in the advanced/metastatic setting.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
32

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Spain
      • Barcelona, Spain, 08028
        • Clinical Trial Site
      • Madrid, Spain, 28034
        • Clinical Trial Site
      • Valencia, Spain, 46018
        • Clinical Trial Site
  • United States
    • California
      • San Diego, California, United States, 92037
        • Clinical Trial Site
      • Santa Monica, California, United States, 90404
        • Clinical Trial Site
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20007
        • Clinical Trial Site
    • Florida
      • Lake Mary, Florida, United States, 32746
        • Clinical Trial Site
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • Clinical Trial Site
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Clinical Trial Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Histologically or cytologically confirmed ER+ and HER2-advanced breast cancer (metastatic, recurrent, or unresectable)
  • Women must be postmenopausal, or pre-/peri-menopausal women must be on ovarian suppression
  • Measurable disease or non-measurable (evaluable) disease per RECIST v1.1
  • Received a minimum of 1 and up to 3 lines of anti-cancer therapy in the advanced/metastatic setting: must have received and progressed on (or were intolerant to) a CDK 4/6 inhibitor, either alone or in combination; must have received at least one endocrine therapy, either alone or in combination; may have received up to one line of chemotherapy
  • Must be willing to use dexamethasone mouthwash for the prevention of everolimus-induced stomatitis
  • ECOG performance status of 0 or 1

Exclusion Criteria:

  • Untreated brain metastases or brain metastases requiring steroids above physiologic replacement doses
  • Prior treatment with ARV-471
  • Prior treatment targeting mTOR (e.g. everolimus)
  • Prior anticancer or investigational drug treatment within 28 days (fulvestrant) or 14 days (tamoxifen or aromatase inhibitor, or CDK 4/6 inhibitor) before the first dose of study drug
  • Prior anticancer or investigational anticancer drug therapy within 28 days or 5 half-lives (whichever is shorter) before the first dose of study drug, except as mentioned above
  • Any of the following in the previous 12 months: myocardial infarction, severe/unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure, cerebrovascular accident, transient ischemic attack, symptomatic pulmonary embolism, or other clinically significant episode of thromboembolism
  • Any of the following in the previous 6 months: congenital long QT syndrome, Torsade de Pointes, sustained ventricular tachyarrhythmia and ventricular fibrillation, left anterior hemiblock, ongoing cardiac arrythmias/dysrhythmias, atrial fibrillation
  • Hypertension that cannot be controlled by medication (>150/90 mmHg despite optimal medical therapy)
  • Active, uncontrolled bacterial, fungal, or viral infection, including hepatitis B virus, hepatitis C virus, known human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome (AIDS)-related illness
  • Known history of drug-induced pneumonitis or other significant symptomatic deterioration of lung function
  • Live vaccines within 14 days before the first dose of study drug
  • Major surgery (as defined by the Investigator) within 4 weeks of first dose of study drug
  • Radiation therapy within 4 weeks of first dose of study drug or prior irradiation to more than 25% of the bone marrow

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: ARV-471 and Everolimus
ARV-471 oral tablets in combination with everolimus administered daily in 28 day cycles
Drug: ARV-471 in combination with Everolimus
ARV-471 oral tablets in combination with everolimus administered daily in 28 day cycles

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of dose limiting toxicities of ARV-471 in combination with everolimus
Time Frame: 35 Days
Dose limiting toxicities in the first 35 days of the study combination treatment characterized by type, frequency, severity (as graded by NCI CTCAE v5.0), timing, seriousness, and relationship to study drug
35 Days
Number of participants with adverse events as a measure of safety and tolerability of ARV-471 in combination with everolimus
Time Frame: 28 calendar days after participant discontinues study treatment
Adverse events as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness, and relationship to study drug combination
28 calendar days after participant discontinues study treatment
Incidence of laboratory abnormalities as a measure of safety and tolerability of ARV-471 in combination with everolimus
Time Frame: 28 calendar days after participant discontinues study treatment
Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE v5.0), and timing
28 calendar days after participant discontinues study treatment
Recommended Phase 2 Dose (RP2D) for ARV-471 in combination with everolimus
Time Frame: 35 Days
35 Days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Overall response rate (ORR) in participants
Time Frame: Up to approximately 1 year
Up to approximately 1 year
Duration of response (DOR) in participants
Time Frame: Up to approximately 1 year
Up to approximately 1 year
Maximum plasma concentrations (Cmax) of ARV-471 and everolimus
Time Frame: At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
Time to maximum plasma concentrations (Tmax) of ARV-471 and everolimus
Time Frame: At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
Area under the concentration-time curve over 24 hours at steady state (AUC(0-24)) of ARV-471 and everolimus
Time Frame: At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
At predefined intervals throughout the treatment period, up to approximately 4 weeks after last dose of investigational products
Clinical benefit rate (CBR) in participants.
Time Frame: Up to approximately 1 year
Clinical benefit response rate based on the summation of CRs, PRs and stable disease of 24 weeks duration or longer.
Up to approximately 1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Arvinas Estrogen Receptor, Inc.

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Pfizer

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 8, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 3, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 25, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 9, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 12, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 15, 2022

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 26, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 23, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ARV-471-mBC-102
  • C4891020 (Other Identifier: Pfizer)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings