Despite benefits of current hormonal therapy (sometimes called endocrine therapy) alone or in combination with targeted treatments for advanced or metastatic breast cancer, these treatment options may not work for everyone.

The VERITAC-3 study is exploring if an investigational medication (ARV-471) may potentially work better than an approved hormonal therapy when taken with palbociclib (IBRANCE®) for treating ER-positive, HER2-negative breast cancer.

The VERITAC-3 study has two parts: Study Lead-In (SLI) and Phase 3.

SLI is currently enrolling participants to determine the best dose of palbociclib to be taken with the investigational medication (ARV-471).

Following SLI completion, Phase 3 will explore whether ARV-471 taken with palbociclib works better than letrozole taken with palbociclib in prolonging the time without disease worsening.

Pfizer and Arvinas Estrogen Receptor, Inc. have partnered to co-develop the investigational medication.

Who may participate

Thank you for considering the VERITAC-3 study. Joining a clinical trial is an important and personal decision. By volunteering in clinical research, you can make a difference.

The VERITAC-3 is enrolling people aged 18 years old or older with ER-positive, HER2-negative advanced breast cancer who have not received treatment for their locally advanced or metastatic disease.

If you think this study may be right for you, use the Get Started button to answer a few questions and find a study site near you.


ER-positive, HER2-negative locoregionally advanced or metastatic breast cancer


18+ years


Male or Female

Each clinical study has its own guidelines for who can participate, called eligibility criteria. However, only the research study staff can determine if you qualify to enroll in the study.

View more eligibility criteria

Get started — See if you may qualify

A first step as you consider participating in these studies is to answer a 5-minute online questionnaire about your health and medical history. Please answer the questions to the best of your ability and to the extent you feel comfortable. You can skip questions, however, providing more information will help our clinical trial finder, a secure system powered by Leal Health, to see if you may be eligible for a study based on your health and medical history.

By entering your information into the online questionnaire, you are creating an account and profile with Leal Health which will allow you to see if you may be eligible for any breast cancer studies. At the end of the online questionnaire, you will be able to see how many studies you may potentially qualify for.

By providing your contact information, you are providing permission for a member of the Leal Health Patient Support Team to contact you and discuss next steps. They will be available to help you navigate the process of finding a study, answering your questions, and helping you prepare to talk with your oncologist.

If you would like to be referred to a nearby clinic, your Patient Support Team Member will ask you to provide written permission for Leal Health to share your contact information with the study team at the clinic who will then contact you and will likely ask you to come in for an appointment. Only the study team can determine if you meet all the study’s eligibility criteria and are able to enroll in the study.

If it appears that you may be eligible to participate in a Pfizer breast cancer study after completing the online questionnaire, you will see the list of potential Pfizer sponsored studies first. If there are no Pfizer sponsored studies in the list, you can provide permission for Leal Health to continue searching for an appropriate study sponsored by another organization.

We encourage you to review Leal Health’s privacy policy (linked below) before you complete the online questionnaire. Your answers including any personal information will be kept confidential by Leal Health throughout the prescreening process.

Your answers to the online questionnaire will only be linked to you if your responses indicate that you may be eligible to participate in a study and you choose to share your contact information with that study team. Pfizer study team members and our partners will have access to reports containing aggregated (combined) data that will not be directly linked back to you.

What to expect

You will be assigned to a treatment group by chance.

All participants will receive the same dose of the investigational medication (ARV-471) to be taken with palbociclib. However, two different doses of palbociclib will be studied. Researchers want to determine which dose of palbociclib is the best dose to be taken with ARV-471.

This is an open-label study, meaning you and the study doctor will know what treatment dose you are receiving.

Length of study treatment

Depends on how you tolerate the treatment, how your cancer responds, and your personal choice

Number of study visits

Three visits in cycle 1, two visits in cycle 2, and once per cycle thereafter.

Follow up

You’ll be contacted or visit the site 3 months after end of the treatment.

About ER-positive, HER2-negative advanced breast cancer

About 80% of all breast cancers are “ER-positive”, which means that the breast cancer cells have receptors on the outside of their walls that can catch specific hormones in your body. ER-positive cancer cells grow in response to the hormone estrogen; therefore, hormone therapies are likely to work well in this type of breast cancer.

HER2 (human epidermal growth factor receptor 2) proteins are a type of cell surface protein that are involved in normal cell growth. If breast cancer cells don’t have abnormal levels of HER2 proteins, the breast cancer is considered HER2-negative.

About ER-positive, HER2-negative advanced breast cancer

Happy diverse people together in the park – Pfizer Clinical Trials
Happy diverse people together in the park – Pfizer Clinical Trials

Frequently asked questions

Will I receive active medication?

All participants will receive the same dose of the investigational medication (ARV-471) to be taken with palbociclib. There is no placebo in this study.

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How should I take the study medications?

All the study medication must be taken by mouth with food at approximately the same time, every day in the morning.

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How often do you assess my tumor?

Your tumor will be assessed every 8 weeks for the first 3 assessments, every 12 weeks thereafter, same as the standard of care for metastatic disease. This includes scans and measurement of skin lesions. Bone scans will be carried out every 24 weeks, if needed.

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How long do study visits last?

Most study visits last for about 2-3 hours. There are some longer visits that may last about 6-8 hours. You will be given information in advance on which study visit will take longer so that you can plan your day.

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Do I have access to the study drugs outside of this study?

You do not have to participate in this study to receive palbociclib because this drug is available outside of this research study by a doctor’s prescription.

However, because researchers are still studying the study drugs given together, you can only have the study drugs during your participation in the study, and not after you have finished taking part.

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Will I be reimbursed for study-related cost?

You may be reimbursed for any reasonable expenses that you may have as a result of taking part in this study. This may include mileage, parking, meals, or hotel accommodation and other travel-related expenses.

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