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AzTrials

Breast CancerPhase 1/2NCT06206837

A Study to Learn About Vepdegestrant When Given With PF-07220060 to People With Advanced or Metastatic Breast Cancer.

A Phase 1/2 study testing vepdegestrant and PF-07220060 in people with Breast Cancer, run by Pfizer at 58 sites in 8 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The purpose of this study is to learn about the safety and effects of giving vepdegestrant along with PF-07220060. Vepdegestrant is studied to see if it can be a possible treatment for advanced metastatic breast cancer. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Breast Cancer
What is being tested?
vepdegestrant and PF-07220060
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
71 participants
Where
58 sitesin 8 countries
Study dates
19 Feb 2024to 25 May 2027
Phase
Phase 1/2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Histological or cytological diagnosis of breast cancer. At time of enrollment this must not be amenable to surgical resection with curative intent (≥1% ER+ stained cells as per local practice on the most recent tumor biopsy HER2- tumor by IHC or in-situ hybridization per ASCO/CAP).
  • prior anticancer therapies: Phase 1b: at least 1 line of SOC for A/MBC; Prior fulvestrant allowed; ≤1 prior chemotherapy line (no antibody-drug conjugates permitted) for A/MBC setting allowed. Phase 2: At least one and maximum 2 lines of ET in A/MBC setting and most recent ET-based regimen for >6 months.
  • 1, and only 1, prior CDK4/6 inhibitor-based regimen required. Up to 1 prior regimen of cytotoxic chemotherapy (no antibody-drug conjugates permitted) in the A/MBC setting; Prior fulvestrant allowed.
  • Participant with only non-measurable lesion (Phase1b) or at least 1 measurable lesion as defined by RECIST v1.1. (Phase2) are eligible.
  • ECOG PS = 0 or 1 (Phase1b) ; ≤2 (Phase2)

Who cannot join

  • visceral crisis at risk of life-threatening complications in the short term.
  • Any condition precluding an adeguate absorption of study interventions.
  • newly diagnosed brain metastases, or symptomatic central nervous system (CNS) metastases, carcinomatous meningitis, or leptomeningeal disease. Participants with a history of CNS metastases or cord compression are eligible if they have been definitively treated, clinically stable and discontinued anti-seizure medications and corticosteroids for at least 28 days prior to enrollment in the of study.
  • history of any other tumor malignancies within the past 3 years, except for the following: (1) adequately treated basal or squamous cell carcinoma of the skin; (2) curatively treated in situ carcinoma of the cervix. Inflammatory breast cancer are excluded
  • impaired cardiovascular function or clinically significant cardiovascular diseases.
  • concurrent administration of medications, food, or herb supplements that are strong inhibitors/inducers of CYP3A or UGT2B7, moderate inducers of CYP34 (Phase1b only) and drugs known to predispose to Torsade de Pointes or QT interval prolongation.
  • renal impairment, not adequate liver function and/or bone marrow function.
  • known active infection

Trial locations and contacts

58 sites in 8 countries.

58 sites in 8 countries

United States34 sites

  • MSK Basking Ridge

    Basking Ridge, New Jersey, 07920

  • MSK Commack

    Commack, New York, 11725

  • University of Utah, Farmington Health Center

    Farmington, Utah, 84025

  • Highlands Oncology

    Fayetteville, Arkansas, 72703

  • UCHealth Poudre Valley Hospital

    Fort Collins, Colorado, 80524

  • UCHealth Harmony

    Fort Collins, Colorado, 80528

  • START Midwest

    Grand Rapids, Michigan, 49546

  • UCHealth Greeley Hospital

    Greeley, Colorado, 80634

  • MSK Westchester

    Harrison, New York, 10604

  • Hoag Health Center Irvine

    Irvine, California, 92618

  • Hoag Hospital Irvine

    Irvine, California, 92618

  • UCHealth - Medical Center of the Rockies

    Loveland, Colorado, 80538

  • MSK Monmouth

    Middletown, New Jersey, 07748

  • MSK Bergen

    Montvale, New Jersey, 07645

  • Smilow Cancer Hospital - Yale New Haven Health

    New Haven, Connecticut, 06510

  • Yale - New Haven Hospital - Yale Cancer Center

    New Haven, Connecticut, 06510

  • Smilow Cancer Hospital Phase 1 Unit

    New Haven, Connecticut, 06511

  • Rockefeller Outpatient Pavilion (53rd Street)

    New York, New York, 10022

  • Evelyn H. Lauder Breast and Imaging Center (BAIC).

    New York, New York, 10065

  • Memorial Sloan Kettering Cancer Center

    New York, New York, 10065

  • Hoag Memorial Hospital Presbyterian

    Newport Beach, California, 92663

  • Clinical and Translational Research Unit (CTRU)

    Palo Alto, California, 94304

  • Stanford Cancer Center

    Palo Alto, California, 94304

  • Stanford Cancer Institute - Clinical Trials Office

    Palo Alto, California, 94304

  • Highlands Oncology

    Rogers, Arkansas, 72758

  • University of Utah, Sugar House Health Center

    Salt Lake City, Utah, 84106

  • Huntsman Cancer Institute

    Salt Lake City, Utah, 84112

  • START San Antonio

    San Antonio, Texas, 78229

  • UCSF Medical Center at Mission Bay

    San Francisco, California, 94158

  • South Jordan Health Center - University of Utah

    South Jordan, Utah, 84106

  • Highlands Oncology Group

    Springdale, Arkansas, 72762

  • Smilow Cancer Hospital - Trumbull

    Trumbull, Connecticut, 06611

  • MSK Nassau

    Uniondale, New York, 11553

  • START Mountain Region

    West Valley City, Utah, 84119

Other trials in United States

Belgium4 sites

  • Institut Jules Bordet

    Anderlecht, Bruxelles-capitale, Région de, 1070

  • Antwerp University Hospital

    Edegem, Antwerpen, 2650

  • AZ Groeninge Campus Kennedylaan

    Kortrijk, West-vlaanderen, 8500

  • UZ Leuven

    Leuven, Vlaams-brabant, 3000

Other trials in Belgium

Japan4 sites

  • National Cancer Center Hospital

    Chuo-ku, Tokyo, 104-0045

  • National Cancer Center Hospital East

    Kashiwa, Chiba, 277-8577

  • Showa Medical University Hospital

    Tokyo, 142-8666

  • Kanagawa cancer center

    Yokohama, Kanagawa, 2418515

Other trials in Japan

Spain4 sites

  • Hospital Universitari Vall d'Hebron

    Barcelona, Barcelona [barcelona], 08035

  • Hospital Universitario Arnau de Vilanova de Lleida

    Lleida, Lleida [lérida], 25198

  • Hospital Universitario 12 de Octubre

    Madrid, Madrid, Comunidad de, 28041

  • Hospital Universitario Virgen Del Rocio

    Seville, 41013

Other trials in Spain

Canada3 sites

  • The Ottawa Hospital - General Campus

    Ottawa, Ontario, K1H 8L6

  • Sunnybrook Research Institute

    Toronto, Ontario, M4N 3M5

  • Princess Margaret Cancer Centre

    Toronto, Ontario, M5G 2M9

Other trials in Canada

China3 sites

  • Sun Yat-sen University Cancer Center

    Guangzhou, Guangdong, 510060

  • Wuhan Union Hospital Cancer Center

    Wuhan, Hubei, 430023

  • The First Affiliated Hospital of Xi'an Jiaotong University

    Xi'an, Shaanxi, 710061

Other trials in China

France3 sites

  • Institut Paoli-Calmettes

    Marseille, Provence-Alpes-Côte d'Azur Region, 13273

  • Institut Régional du Cancer Montpellier

    Montpellier, Hérault, 34298

  • Institut de Cancérologie de l'Ouest

    Saint-Herblain, Loire-atlantique, 44805

Other trials in France

Puerto Rico3 sites

  • BRCR Global - Mayaguez Administrative Office

    Mayagüez, 00680

  • BRCR Global - Mayagüez

    Mayagüez, 00682

  • Pan American Center for Oncology Trials, LLC

    Rio Piedras, 00935

Other trials in Puerto Rico

About this study

Official title: AN INTERVENTIONAL SAFETY AND EFFICACY PHASE 1B/2, OPEN-LABEL STUDY TO INVESTIGATE TOLERABILITY, PK, AND ANTITUMOR ACTIVITY OF VEPDEGESTRANT (ARV-471/PF-07850327), AN ORAL PROTEOLYSIS TARGETING CHIMERA, IN COMBINATION WITH PF-07220060 IN PARTICIPANTS AGED 18 YEARS AND OLDER WITH ER+/HER2- ADVANCED OR METASTATIC BREAST CANCER

The purpose of this study is to learn about the safety and effects of giving vepdegestrant along with PF-07220060. Vepdegestrant is studied to see if it can be a possible treatment for advanced metastatic breast cancer. This type of cancer would have spread from where it started (breast) to other parts of the body and would be tough to treat. The study is seeking for participants who have breast cancer that:

  • is hard to treat (advanced) and may have spread to other organs (metastatic).
  • is sensitive to hormonal therapy (it is called estrogen receptor positive).
  • is no longer responding to treatments taken before starting this study.
Read more

All the participants will receive vepdegestrant and PF-07220060. Both medicines will be taken by mouth. The medicines will be taken at home. The experience of people receiving the study medicines will be studied. This will help see if the study medicines are safe and effective. Participants will continue to take vepdegestrant and PF-07220060 until:

  • their cancer is no longer responding, or
  • side effects become too severe. They will have visits at the study clinic about every 4 weeks.
Read the detailed description

C4891026 is a prospective, open-label, multicenter, Phase 1b/2 study to evaluate the safety, antitumor activity, and pharmacokinetic (PK) of vepdegestrant in combination with PF-07220060 in the treatment of participants with Estrogen Receptor Positive/Human Epidermal Growth Factor Receptor 2 Negative (ER+/HER2-) Advanced or Metastatic Breast Cancer.

Conditions
Breast Cancer
Being tested
vepdegestrant, PF-07220060
Keywords
Proteolysis Targeting Chimera (PROTAC), metastatic breast cancer
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • vepdegestrantDrug

    Also called ARV-471 / PF07850327

    Daily oral dosages of vepdegestrant continuously, dose escalation/de-escalation in Phase 1b until recommended phase 2 dose (RP2D) determined, cycles lasting 28 days

  • PF-07220060Drug

    Daily oral dosages of PF-07220060 continuously, dose escalation/de-escalation in Phase 1b until recommended phase 2 dose (RP2D) determined, cycles lasting 28 days

Study groups in NCT06206837
Study groupRoleWhat they receive
vepdegestrant in combination with PF-07220060Experimentalvepdegestrant administered orally once daily (QD) continuously and PF-07220060 administered orally twice daily (BID) continuously on 28-day cycles
Receives: Drug: vepdegestrant; Drug: PF-07220060

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants With Dose-Limiting Toxicities (DLTs): Phase 1b

    Hematological DLT: neutropenic fever; Grade>=3 thrombocytopenia associated with Grade>=2(clinically significant)bleeding and Grade4 neutropenia/thrombocytopenia lasting <7 days. Non-hematological: Grade>=3 toxicities clinically significant,except those that were not been maximally treated;Grade 2 aspartate aminotransferase(AST), alanine aminotransferase(ALT)/alkaline phosphatase(ALP) levels at baseline as result of liver/bone metastasis,AST,ALT and ALP level>8*baseline/AST/ALT >5*baseline for>=14 days; Hy's Law(concomitant ALT/AST elevation of >=3*upper limit of normal [ULN], total bilirubin elevation>=2*ULN without clear alternative etiology); Grade≥3 electrolyte abnormality with clinical sequelae; QTcF prolongation:any Grade>=3 QT prolongation without clear alternative etiology;any adverse event (AE) attributed to Vepdegestrant and/or PF-07220060 resulting in failure to deliver 75% of doses for either/both agents and any death not clearly due to underlying disease/extraneous causes.

    Measured: Cycle 1 (28 days)

  2. Percentage of Participants With Confirmed Objective Response (OR) by Derived Investigator Assessment: Phase 2

    OR was defined as best overall response (BOR) of confirmed complete response (CR) or partial response (PR) according to response evaluation criteria in solid tumors (RECIST) version (v) 1.1. CR was defined as complete disappearance of all target lesions, except for nodal disease, complete disappearance of all non-target lesions and no new lesions. All nodes, both target and non-target, must decrease to normal (short axis <10 millimeter [mm]). PR was defined as at least a >=30% decrease from baseline in the sum of diameters of all target lesions. The short diameter was used in the sum for nodal target lesions, while the longest diameter was used in the sum for non-nodal target lesions, all target lesions were assessed.

    Measured: From the date of first dose of study treatment combination until the first documentation of disease progression (PD), death or start of new anticancer therapy, whichever occurred first (maximum treatment exposure of 9.5 months for Phase 2)

Secondary outcomes (29)

  1. Number of Participants With Treatment Emergent Adverse Events (TEAEs), Treatment Emergent Serious Adverse Events (TESAEs) and Treatment Related TEAEs: Phase 1b

    AE: any untoward medical occurrence in clinical study participant, temporally associated with use of study treatment, whether or not considered related to study treatment. Serious adverse event (SAE): any untoward medical occurrence, at any dose met one or more of following criteria: death, life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, congenital anomaly/birth defect or other important medical events. AEs includes both SAEs and all other AEs (non-SAEs). TEAEs will be those events with onset dates occurring during the on-treatment period. Relatedness to study drug judged by investigator.

    Measured: From the date of first dose of study treatment combination through study completion

  2. Number of Participants With Laboratory Abnormalities: Phase 1b

    Laboratory parameters assessed: hemoglobin, platelets, white blood cells (WBC), absolute neutrophils, absolute lymphocytes, absolute monocytes, absolute eosinophils, absolute basophils, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), sodium, potassium, magnesium, chloride, total calcium, total bilirubin, urea or blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR), uric acid, glucose (fasted), albumin, phosphorus, lipase and amylase.

    Measured: From the date of first dose of study treatment combination through study completion

  3. Number of Participants With Electrocardiogram (ECG) Abnormalities: Phase 1b

    Twelve lead ECGs were measured with the participant in a supine position after at least 5 minutes.

    Measured: From the date of first dose of study treatment combination through study completion

  4. Percentage of Participants With Confirmed OR by Derived Investigator Assessment: Phase 1b

    OR was defined as BOR of confirmed CR or PR according to RECIST v 1.1. CR was defined as complete disappearance of all target lesions, except for nodal disease, complete disappearance of all non-target lesions and no new lesions. All nodes, both target and non-target, must decrease to normal (short axis <10 mm). PR was defined as at least a >=30% decrease from baseline in the sum of diameters of all target lesions. The short diameter was used in the sum for nodal target lesions, while the longest diameter was used in the sum for non-nodal target lesions, all target lesions were assessed.

    Measured: From the date of first dose of study treatment combination through study completion

  5. Duration of Response (DOR) by Derived Investigator Assessment: Phase 1b

    DoR: for participants with OR: time from first documentation of CR/PR to first documentation of PD/death. CR: complete disappearance of all target lesions (L), except nodal disease, complete disappearance of all non-target L and no new L. Both target and non-target nodes, must decrease to normal. PR: >=30% decrease from baseline in sum of diameters of target L. Short diameter used in sum for nodal target L, longest diameter used in sum for non-nodal target L. PD: 20% increase in sum of diameter of target measurable L above smallest sum observed, minimum absolute increase of 5 mm for target L/unequivocal progression of pre-existing L for non-target L. DOR censored on date of last adequate disease assessment for participants who did not have DOR event, discontinued study treatment due to withdrawal of consent prior to event, started new anticancer therapy prior to event, had event after gap of >2 missing disease assessments, or lost to follow-up. Kaplan-Meier method will be used.

    Measured: From the date of first dose of study treatment combination through study completion

  6. Clinical Benefit Response (CBR) by Derived Investigator Assessment: Phase 1b

    CBR was defined as percentage of participants with BOR of confirmed CR or PR at any time, or stable disease (SD) >=24 weeks as per RECIST v1.1. CR: complete disappearance of all target lesions, except for nodal disease, complete disappearance of all non-target lesions and no new lesions. All nodes, both target and non-target, must decrease to normal (short axis<10 mm). PR: at least >=30% decrease from baseline in sum of diameters of all target lesions. Short diameter was used in sum for nodal target lesions, while longest diameter was used in sum for non-nodal target lesions, all target lesions were assessed. SD: did not qualify for CR, PR, PD. All target lesions were assessed. PD: 20% increase in sum of diameters of target measurable lesions above smallest sum observed, minimum absolute increase of 5mm for target lesions/unequivocal progression of pre-existing lesions for non-target lesion.

    Measured: From the date of first dose of study treatment combination through study completion

  7. Progression Free Survival (PFS) by Derived Investigator Assessment: Phase 1b

    PFS was defined as the time from the date of first dose of study interventions to the date of first documentation of PD or death due to any cause, whichever occurred first as per RECIST v1.1. PD: 20% increase in sum of diameters of target measurable lesions above smallest sum observed, minimum absolute increase of 5mm for target lesions/unequivocal progression of pre-existing lesions for non-target lesion. PFS was censored on the date of last adequate disease assessment for those who did not have a PFS event, discontinued the study treatment due to withdrawal of consent prior to an event, started a new anticancer therapy prior to an event, had an event after a gap of 2 or more missing disease assessments, or lost to follow-up. Kaplan-Meier method will be used.

    Measured: From the date of first dose of study treatment combination through study completion

  8. Plasma Concentration of Vepdegestrant (ARV-471) and Its Epimer ARV-473: Phase 1b

    Plasma concentrations of ARV-471 and its epimer ARV-473 were reported in this outcome measure.

    Measured: Cycle 1, Day 8: Pre-dose; Cycle 1 Day 15: Pre-dose, 30 minutes, 1, 2, 4 ,6, 8 and 12 hours post-dose; Cycle 2 Days 1 and 15: Pre-dose, anytime between 4 to 8 hour post-dose; Cycles 3, 5, and 7, Day 1: Pre-dose

  9. Plasma Concentration of PF-07220060: Phase 1b

    Measured: Pre-dose (0 hour) of Day 8 of Cycle 1; pre-dose (0 hour), 0.5,1,2,4,6,8 and 12 hours post-dose of Day 15 of Cycle 1; Pre-dose (0 hour) and anytime between 4 to 8 hour post-dose of Day 1 and 15 of Cycle 2; Pre-dose (0 hour) of Day 1 of Cycle 3, 5 and 7

  10. Steady State Maximum Observed Plasma Concentration (Cmax,ss) of Vepdegestrant (ARV-471) and Its Epimer ARV-473: Phase 1b

    Cmax,ss was the steady-state maximum concentration of ARV-471 after multiple doses and was directly observed from data. ARV-473 is an epimer of ARV-471.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  11. Cmax,ss of PF-07220060: Phase 1b

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  12. Steady State Time to Maximum Plasma Concentration (Tmax,ss) of Vepdegestrant (ARV-471) and Its Epimer ARV-473: Phase 1b

    Tmax,ss was the steady-state time to maximum plasma concentration after multiple doses and was directly observed from data. ARV-473 is an epimer of ARV-471. ARV-473 is an epimer of ARV-471.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  13. Tmax,ss of PF-07220060: Phase 1b

    Tmax,ss was the steady-state time to maximum plasma concentration after multiple doses and was directly observed from data.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  14. Steady State Area Under the Plasma Concentration-Time Curve From Time Zero to the Time of the Last Quantifiable Concentration (AUClast,ss) of Vepdegestrant (ARV-471) and Its Epimer ARV-473: Phase 1b

    AUClast,ss was defined as area under the plasma concentration time curve from time zero to the last measurable concentration as steady state. AUClast,ss was calculated using linear/log trapezoidal method.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  15. AUClast,ss of PF-07220060: Phase 1b

    AUClast,ss was defined as area under the plasma concentration time curve from time zero to the last measurable concentration as steady state. AUClast,ss was calculated using linear/log trapezoidal method.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  16. Apparent Total Clearance (CL/F) of Vepdegestrant (ARV-471): Phase 1b

    Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. CL/F was calculated as dose administered divided by AUCinf. AUCinf was calculated as AUClast + (Clast/kel), where, AUClast= area under the concentration-time curve from time 0 to time of last measurable concentration, Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis and kel was the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  17. CL/F of PF-07220060: Phase 1b

    Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. CL/F was calculated as dose administered divided by AUCinf. AUCinf was calculated as AUClast + (Clast/kel), where, AUClast= area under the concentration-time curve from time 0 to time of last measurable concentration, Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis and kel was the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  18. Apparent Volume of Distribution (Vz/F) of PF-07220060: Phase 1b

    Vz/F was calculated as Dose/(AUCinf * kel). AUCinf was calculated as AUClast + (Clast/kel), where, AUClast= area under the concentration-time curve from time 0 to time of last measurable concentration, Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis and kel was the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  19. Terminal Half-Life (t1/2) of PF-07220060: Phase 1b

    T1/2 was calculated as loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Predose (0 hours), 0.5, 1, 2, 4, 6, 8, and 12 hours post dose on Cycle 1 Day 15

  20. DOR by Derived Investigator Assessment: Phase 2

    DOR: for participants with OR: time from first documentation of CR/PR to first documentation of PD/death. CR: complete disappearance of all target lesions (L), except nodal disease, complete disappearance of all non-target L and no new L. Both target and non-target nodes, must decrease to normal. PR: >=30% decrease from baseline in sum of diameters of target L. Short diameter used in sum for nodal target L, longest diameter used in sum for non-nodal target L. PD: 20% increase in sum of diameter of target measurable L above smallest sum observed, minimum absolute increase of 5 mm for target L/unequivocal progression of pre-existing L for non-target L. DOR censored on date of last adequate disease assessment for participants who did not have DOR event, discontinued study treatment due to withdrawal of consent prior to event, started new anticancer therapy prior to event, had event after gap of >2 missing disease assessments, or lost to follow-up. Kaplan-Meier method will be used.

    Measured: From the date of first dose of study treatment combination through study completion

  21. Percentage of Participants With CBR by Derived Investigator Assessment: Phase 2

    CBR was defined as percentage of participants with BOR of confirmed CR or PR at any time, or stable disease (SD) >=24 weeks as per RECIST v1.1. CR: complete disappearance of all target lesions, except for nodal disease, complete disappearance of all non-target lesions and no new lesions. All nodes, both target and non-target, must decrease to normal (short axis<10 mm). PR: at least >=30% decrease from baseline in sum of diameters of all target lesions. Short diameter was used in sum for nodal target lesions, while longest diameter was used in sum for non-nodal target lesions, all target lesions were assessed. SD: did not qualify for CR, PR, PD. All target lesions were assessed. PD: 20% increase in sum of diameters of target measurable lesions above smallest sum observed, minimum absolute increase of 5mm for target lesions/unequivocal progression of pre-existing lesions for non-target lesion.

    Measured: From the date of first dose of study treatment combination through study completion

  22. PFS by Derived Investigator Assessment: Phase 2

    PFS was defined as the time from the date of first dose of study interventions to the date of first documentation of PD or death due to any cause, whichever occurred first as per RECIST v1.1. PD: 20% increase in sum of diameters of target measurable lesions above smallest sum observed, minimum absolute increase of 5mm for target lesions/unequivocal progression of pre-existing lesions for non-target lesion. PFS was censored on the date of last adequate disease assessment for those who did not have a PFS event, discontinued the study treatment due to withdrawal of consent prior to an event, started a new anticancer therapy prior to an event, had an event after a gap of 2 or more missing disease assessments, or lost to follow-up. Kaplan-Meier method will be used.

    Measured: From the date of first dose of study treatment combination through study completion

  23. Overall Survival (OS): Phase 2

    OS was defined as the time from the date of first dose of study treatment combination to the date of death due to any cause. Participants last known to be alive were censored at the date of last contact. Kaplan-Meier method will be used.

    Measured: From the date of first dose of study treatment combination through study completion

  24. Number of Participants With TEAEs, TESAEs and Treatment Related TEAEs: Phase 2

    AE: any untoward medical occurrence in clinical study participant, temporally associated with use of study treatment, whether or not considered related to study treatment. SAE: any untoward medical occurrence, at any dose met one or more of following criteria: death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, congenital anomaly/birth defect or other important medical events. AEs includes both SAEs and all other AEs (non-SAEs). TEAEs will be those events with onset dates occurring during the on-treatment period. Relatedness to study drug judged by investigator.

    Measured: From the date of first dose of study treatment combination through study completion

  25. Number of Participants With ECG Abnormalities: Phase 2

    Twelve lead ECGs were measured with the participant in a supine position after at least 5 minutes.

    Measured: From the date of first dose of study treatment combination through study completion

  26. Number of Participants With Laboratory Abnormalities: Phase 2

    Laboratory parameters assessed included hemoglobin, platelets, WBC, absolute neutrophils, absolute lymphocytes, absolute monocytes, absolute eosinophils, absolute basophils, ALT, AST, ALP, sodium, potassium, magnesium, chloride, total calcium, total bilirubin, urea or BUN, creatinine, eGFR, uric acid, glucose (fasted), albumin, phosphorus, lipase and amylase.

    Measured: From the date of first dose of study treatment combination through study completion

  27. Plasma Concentration of Vepdegestrant (ARV-471) and Its Epimer ARV-473: Phase 2

    Plasma concentrations of ARV-471 and its epimer ARV-473 were reported in this outcome measure.

    Measured: Cycle 1, Day 15 and Cycle 2 Days 1 and 15: Pre-dose, anytime between 4 to 8 hour post-dose; Cycles 3, 5, and 7, Day 1: Pre-dose

  28. Plasma Concentration of PF-07220060: Phase 2

    Plasma concentrations of ARV-471 and its epimer ARV-473 were reported in this outcome measure.

    Measured: Cycle 1, Day 15 and Cycle 2 Days 1 and 15: Pre-dose, anytime between 4 to 8 hours post-dose; Cycles 3, 5, and 7, Day 1: Pre-dose

  29. Change From Baseline in Circulating Tumor Deoxyribonucleic Acid (ctDNA) Plasma Level: Phase 2

    Measured: Baseline and up to End of Treatment

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Jan 2024
  2. Study start19 Feb 2024
  3. Primary completion5 Sep 2025
  4. Study completion25 May 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1/2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Sequential
Model description
Phase 1b will use an escalation/de-escalation approach to determine the recommended phase 2 dose (RP2D) of vepdegestrant when administered in combination with PF-07220060. The decision to escalate the starting dose level of vepdegestrant will be using mTPI-2 decision criteria based on the number of dose limiting toxicity (DLT)-evaluable participants and the number of DLTs in those participants during the DLT observation period (Cycle 1). Phase 2 will further evaluate the preliminary antitumor activity and safety of the combination RP2D.
Masking
None (open label)
Enrolment
71 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06206837
Sponsor's protocol ID
C4891026
Other IDs
TACTIVE-K, 2023-508130-33-00, 2023
Status last verified
Sep 2026
First submitted
13 Dec 2023
Last updated
30 Sep 2026
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing vepdegestrant and PF-07220060 in people with Breast Cancer, run by Pfizer at 58 sites in 8 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 30 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 58 sites in United States, Belgium, Japan, Spain, Canada and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 30 Sep 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Dose-Limiting Toxicities (DLTs): Phase 1b (time frame: Cycle 1 (28 days)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06206837.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2026.

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