ARV-471 + Palbociclib for Advanced Breast Cancer
(VERITAC-3 Trial)

Recruiting in Palo Alto (17 mi)

+40 other locations

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 3

Waitlist Available

Sponsor: Pfizer

No Placebo Group

Pivotal Trial (Near Approval)

Prior Safety Data

Breakthrough Therapy

Trial Summary

What is the purpose of this trial?The purpose of this study is to understand the safety and effects of the study medicine ARV-471 (PF-07850327) given together with palbociclib in advanced breast cancer. In particular, the study will compare the combination of ARV-471 plus palbociclib to standard of care therapy (letrozole plus palbociclib). Both letrozole and palbociclib are medicines already used for treatment of breast cancer. ARV-471 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 ARV-471 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 ARV-471. In the Phase 3, half of the participants will take ARV-471 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.

Eligibility Criteria

This trial is for adults with advanced breast cancer that can't be cured by surgery or radiation, who haven't had systemic treatment for their recurrent or metastatic disease. They should have estrogen receptor positive and HER2 negative tumors, good performance status (ECOG 0-2), and be able to provide tissue samples.

Inclusion Criteria

Phase 3 only: Participants should be willing to provide blood and tumor tissue

I haven't had systemic treatment for my cancer that has returned or spread.

My breast cancer is ER positive and HER2 negative.

+3 more

Exclusion Criteria

My liver, kidneys, and bone marrow are not working well.

I cannot take pills normally due to severe nausea, vomiting, or certain stomach/intestinal surgeries.

I have heart problems or significant heart disease.

+3 more

Participant Groups

The study tests ARV-471 combined with palbociclib against the standard letrozole plus palbociclib in treating advanced breast cancer. Initially, two doses of palbociclib are tested to find the best one for Phase 3, where participants will randomly receive either combination orally once daily until progression or unacceptable side effects.

2Treatment groups

Experimental Treatment

Active Control

Group I: Arm A (Investigational Arm)Experimental Treatment2 Interventions

Participants will receive: * ARV-471, orally, once daily, continuously, in a 28-day cycle, plus * Palbociclib, orally, once daily for 21 consecutive days followed by 7 days off treatment in a 28 day cycle

Group II: Arm B (Comparator Arm):Active Control2 Interventions

Participants will receive: * Letrozole, orally, once daily, continuously, in a 28-day cycle, plus * Palbociclib, orally, once daily for 21 consecutive days followed by 7 days off treatment, in a 28-day cycle.