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Advanced Breast CancerPhase 1NCT07318805

A Study to Learn About the Study Medicine Called PF-08032562 in People With Advanced or Metastatic Solid Tumors

A Phase 1 study testing PF-08032562, Fulvestrant and Cetuximab in people with Advanced Breast Cancer and Metastatic Breast Cancer (HR+/ HER2-), run by Pfizer at 13 sites in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

The purpose of this study is to learn about the safety and effects of the study medicine when given alone or together with other anti-cancer therapies. Anti-cancer therapy is a type of treatment to stop the growth of cancer. This study also aims to find the best amount of study medication. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
PF-08032562, Fulvestrant and Cetuximab
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
260 participants
Where
13 sitesUnited States
Study dates
23 Dec 2025to 14 Apr 2030
Phase
Phase 1
Are there results?
Not yet: the study is under way

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

  • 18 years of age or older
  • Advanced or metastatic cancer of the breast or colon Part 1A: metastatic or advanced breast cancer or colorectal cancer for which no standard therapy is available Part 1B: metastatic or advanced breast cancer with disease progression after at least 1 line of treatment with an endocrine therapy and CDK4/6 inhibitor in the advanced or metastatic setting Part 1C: metastatic or advanced colorectal cancer with at least having received chemotherapy and/or targeted therapy if appropriate Part 1D: metastatic or advanced colorectal cancer without any prior chemotherapy for advanced or metastatic disease Part 2A: metastatic or advanced breast cancer with disease progression after at least 1 prior line of CDK4/6 inhibitor and at least 1 prior line of endocrine therapy Part 2B: metastatic or advanced colorectal cancer with at least having received chemotherapy and/or targeted therapy if appropriate Part 2C: metastatic or advanced colorectal cancer without any prior chemotherapy for advanced or metastatic disease
  • Measurable disease
  • ECOG performance status 0 or 1

Who cannot join

  • Active malignancy within 3 years prior to enrollment
  • Known symptomatic brain metastases requiring steroids
  • Advanced/metastatic, symptomatic, visceral spread, that are at risk of life-threatening complications in the short term
  • Prior irradiation to >25% of the bone marrow
  • Hypertension that cannot be controlled by optimal medical therapy
  • Renal impairment
Show all 11Show fewer
  • Hepatic dysfunction
  • Cardiac abnormalities
  • Active bleeding disorder
  • Active or history of clinically significant GI disease
  • Other unacceptable abnormalities as defined by protocol

Trial locations and contacts

13 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Pfizer CT.gov Call Center contact

1-800-718-1021

ClinicalTrials.gov_Inquiries@pfizer.com

13 sites in 1 country

United States13 sites, 13 recruiting

  • The University of Texas MD Anderson Cancer Center - Conroe

    Conroe, Texas, 77384

    Recruiting

  • City of Hope (City of Hope National Medical Center, City of Hope Medical Center)

    Duarte, California, 91010

    Recruiting

  • START Midwest, LLC

    Grand Rapids, Michigan, 49546

    Recruiting

  • The University of Texas - M.D. Anderson Cancer Center

    Houston, Texas, 77030

    Recruiting

  • The University of Texas, MD Anderson Cancer Center - West Houston

    Houston, Texas, 77079

    Recruiting

  • The University of Texas, MD Anderson Cancer Center - League City

    League City, Texas, 77573

    Recruiting

  • Memorial Sloan Kettering Cancer Center - Investigational Drug Service Pharmacy

    Long Island City, New York, 11101

    Recruiting

  • Memorial Sloan Kettering Cancer Center - David H. Koch Center for Cancer Care (74th Street).

    New York, New York, 10021

    Recruiting

  • Memorial Sloan Kettering Cancer Center 53rd street.

    New York, New York, 10022

    Recruiting

  • Memorial Sloan Kettering Cancer Center - Main Campus

    New York, New York, 10065

    Recruiting

  • START San Antonio

    San Antonio, Texas, 78229

    Recruiting

  • The University of Texas, MD Anderson Cancer Center - Sugar Land

    Sugar Land, Texas, 77478

    Recruiting

  • START Mountain Region

    West Valley City, Utah, 84119

    Recruiting

Other trials in United States

About this study

Official title: A PHASE 1 DOSE ESCALATION AND EXPANSION STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, AND ANTI-TUMOR ACTIVITY OF PF-08032562 IN PARTICIPANTS WITH ADVANCED OR METASTATIC SOLID TUMORS

The purpose of this study is to learn about the safety and effects of the study medicine when given alone or together with other anti-cancer therapies. Anti-cancer therapy is a type of treatment to stop the growth of cancer. This study also aims to find the best amount of study medication.

This study is seeking participants that have advanced or metastatic breast cancer (BC), or advanced or metastatic colorectal cancer (CRC).

Read more

All participants in this study will take the study medication (PF-08032562) as pill by mouth. This will be repeated for 28-day cycles.

Depending on which part of the study participants are enrolled into, they will receive the study medication PF-08032562 alone or in combination with other anti-cancer medications. The study medication (PF-08032562) will be taken by mouth (PO) in combination with other anti-cancer medications given in the study clinic by intramuscular (IM) injection into the muscle or intravenous (IV) infusion that is directly injected into the veins at different times (depending on the treatment) during the 28-day cycle. The study may also test different schedules.

Being tested
PF-08032562, Fulvestrant, Cetuximab, Fluorouracil, Oxaliplatin
Keywords
Carcinoma, Breast, Estrogen Receptor Positive Breast Cancer, HER2- Breast Cancer, Triple Negative Breast Cancer, Colon Cancer
Medical subject headings
Breast Neoplasms, Colorectal Neoplasms, Triple Negative Breast Neoplasms, Colonic Neoplasms

What participants receive

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

  • PF-08032562Drug

    Taken by mouth (PO)

  • FulvestrantDrug

    Also called Faslodex

    Selective Estrogen Receptor Degrader (SERD)

  • CetuximabDrug

    Also called Erbitux, Enlituo

    Monoclonal antibody (EGFR inhibitor)

  • FluorouracilDrug

    Also called 5-FU, 5-Fluorouracil

    Part of FOLFOX chemotherapy regimen cytotoxic chemotherapy (antimetabolite and pyrimidine analog)

  • OxaliplatinDrug

    Also called Eloxatin

    Part of FOLFOX chemotherapy regimen platinum based compound (alkylating agent)

  • LeucovorinDrug

    Also called Folinic Acid, Wellcovorin, Calcium Folinate

    Part of FOLFOX chemotherapy regimen (folic acid analog)

  • BevacizumabDrug

    Also called Zirabev, Avastin

    Monoclonal antibody (VEG-F inhibitor)

Study groups in NCT07318805
Study groupRoleWhat they receive
Part 1 Dose Escalation Cohort 1AExperimentalPF-08032562 monotherapy dose escalation for participants with advanced or metastatic BC or CRC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562
Part 1 Dose Escalation Cohort 1BExperimentalCombination (PF-08032562 + fulvestrant) dose escalation for participants with advanced or metastatic BC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Fulvestrant
Part 1 Dose Escalation Cohort 1CExperimentalCombination (PF-08032562 + cetuximab) dose escalation for participants with advanced or metastatic CRC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Cetuximab
Part 1 Dose Escalation Cohort 1DExperimentalCombination (PF-08032562 + [FOLFOX + bevacizumab]) dose escalation for participants with advanced or metastatic CRC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Fluorouracil; Drug: Oxaliplatin; Drug: Leucovorin; Drug: Bevacizumab
Part 2 Dose Expansion Cohort 2AExperimentalCombination (PF-08032562 + fulvestrant) dose expansion for participants with advanced or metastatic BC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Fulvestrant
Part 2 Dose Expansion Cohort 2BExperimentalPF-08032562 monotherapy or combination (PF-08032562 + cetuximab) dose expansion for participants with advanced or metastatic CRC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Cetuximab
Part 2 Dose Expansion Cohort 2CExperimentalCombination (PF-08032562 + [FOLFOX + bevacizumab]) dose expansion for participants with advanced or metastatic CRC, at different doses and/or schedules of the study drug
Receives: Drug: PF-08032562; Drug: Fluorouracil; Drug: Oxaliplatin; Drug: Leucovorin; Drug: Bevacizumab

What is being measured

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

  1. Part 1 (Dose Escalation): Number of participants with Dose-Limiting Toxicities (DLT)

    Any adverse events that are attributable to one, the other, or both study treatments, occurring in the DLT observation period are considered DLTs, excluding toxicities clearly due to underlying disease or extraneous causes.

    Measured: Baseline up to 28 days

  2. Part 1 (Dose Escalation): Number of participants with laboratory abnormalities

    Number of participants with laboratory test abnormalities.

    Measured: From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

  3. Part 1 (Dose Escalation): Incidence of Adverse Events (AEs)

    An adverse event (AE) was any untoward medical occurrence in a participant who received study medication without regard to possibility of causal relationship to it.

    Measured: From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

  4. Part 2 (Dose Expansion): Objective Response Rate (ORR)

    ORR defined as per Response Evaluation Criteria in Solid Tumors (RECIST v1.1).

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

Secondary outcomes (16)

  1. Part 1 & Part 2: Maximum Observed Serum Concentration (Cmax)

    Evaluate the single and multiple dose PK of PF-08032562 as monotherapy, or in combination with other anti-tumor agents.

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  2. Part 1 & Part 2: Time to Reach Maximum Observed Serum Concentration (Tmax)

    Evaluate the single and multiple dose PK of PF-08032562 as monotherapy, or in combination with other anti-tumor agents.

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  3. Part 1: Area Under the Curve (AUC) from Time Zero to Last Quantifiable Concentration (AUClast)

    Evaluate the single and multiple dose PK of PF-08032562 as monotherapy, or in combination with other anti-tumor agents.

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  4. Part 1: Effect of Food on Cmax

    Evaluate the effect of food on Cmax of PF-08032562 as monotherapy

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  5. Part 1: Effect of Food on Tmax

    Evaluate the effect of food on Tmax of PF-08032562 as monotherapy

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  6. Part 1: Effect of Food on AUClast

    Evaluate the effect of food on AUClast of PF-08032562 as monotherapy

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  7. Part 1: Percent change of immune cells within tumors based on immunohistochemistry assessment

    Evaluate the single and multiple dose pharmacodynamics of PF-08032562 as monotherapy, or in combination with other anti-tumor agents. This measure will assess change in the concentration of immune cell-related cytokines and chemokines as potential pharmacodynamic effects of PF-08032562 using Immunohistochemistry (IHC) assays.

    Measured: Baseline through end of Cycle 1 (each cycle is 28 days)

  8. Part 2 (Dose Expansion): Number of participants with laboratory abnormalities

    Number of participants with laboratory test abnormalities.

    Measured: From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

  9. Part 2 (Dose Expansion): Incidence of Adverse Events (AEs)

    An adverse event (AE) was any untoward medical occurrence in a participant who received study medication without regard to possibility of causal relationship to it.

    Measured: From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

  10. Part 1 & Part 2: Objective Response Rate (ORR) as per Response Evaluation Criteria in Solid Tumors (RECIST v1.1)

    ORR is defined as the percentage of participants in the analysis population having a best overall response (BOR) of confirmed complete response (CR) or confirmed partial response (PR) according to RECIST v1.1.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  11. Part 1 & Part 2: Disease Control Rate (DCR) as per RECIST v1.1

    DCR is defined as the proportion of participants with CR or PR with confirmation, or Stable Disease (SD) per RECIST version 1.1.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  12. Part 1 & Part 2: Clinical Benefit Rate (CBR) as per RECIST v1.1

    CBR is defined as the percentage of participants with a best overall response of CR or PR at any time before Progressive Disease (PD), or non-CR/non-PD or SD for at least 24 weeks from start date of treatment and prior to PD, relative to the appropriate analysis set.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  13. Part 1 & Part 2: Duration of Response (DOR) as per RECIST v1.1

    DOR is defined as the time from first documentation of CR or PR to date of first documentation of PD or death due to any cause.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  14. Part 1 & Part 2: Progression-Free Survival (PFS) as per RECIST v1.1

    PFS is defined as time from start date of treatment to the date of first documentation of PD or death due to any cause.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  15. Part 1 & Part 2: Time to Response (TTR) as per RECIST v1.1

    TTR is defined as the time from start date of treatment to first documentation of CR or PR.

    Measured: Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

  16. Part 2: Overall Survival (OS)

    OS is defined as time from from start date of treatment to the date of death due to any cause

    Measured: Up to approximately 2 years

Timeline

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

  1. First posted6 Jan 2026
  2. Study start23 Dec 2025
  3. Primary completion14 Apr 2029 (estimated)
  4. Study completion14 Apr 2030 (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
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Sequential
Masking
None (open label)
Enrolment
260 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07318805
Sponsor's protocol ID
C6321001
Other IDs
2025-524387-38-00, 2025
Status last verified
Jul 2026
First submitted
4 Dec 2025
Last updated
22 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No: 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 study testing PF-08032562, Fulvestrant and Cetuximab in people with Advanced Breast Cancer and Metastatic Breast Cancer (HR+/ HER2-), run by Pfizer at 13 sites in United States.

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 4 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 22 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 13 sites in United States. 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 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.

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

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

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

Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part 1 (Dose Escalation): Number of participants with Dose-Limiting Toxicities (DLT) (time frame: Baseline up to 28 days). The study lists 4 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 NCT07318805.

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 22 Jul 2026.

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