Study of PF-07220060 With Letrozole in Adults With HR-positive HER2-negative Breast Cancer Who Have Not Received Anticancer Treatment for Advanced/Metastatic Disease

AN INTERVENTIONAL, OPEN-LABEL, RANDOMIZED, MULTICENTER PHASE 3 STUDY OF PF-07220060 PLUS LETROZOLE COMPARED TO CDK4/6 INHIBITOR PLUS LETROZOLE IN PARTICIPANTS OVER 18 YEARS OF AGE WITH HORMONE RECEPTOR (HR)-POSITIVE, HER2-NEGATIVE ADVANCED/METASTATIC BREAST CANCER WHO HAVE NOT RECEIVED ANY PRIOR SYSTEMIC ANTICANCER TREATMENT FOR ADVANCED/METASTATIC DISEASE (FOURLIGHT-3) - FourLight-3

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2071240103

Enrollment

1020

Registered

2025-01-28

Start date

2025-02-20

Completion date

Unknown

Last updated

2026-09-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

HR-positive, HER2-negative Advanced or Metastatic Breast Cancer

Interventions

*Arm A (Experimental) PF-07220060 plus Letrozole *Arm B (Active comparator) Investigator's Choice of CDK4/6 inhibitor (Abemaciclib, palbociclib or ribociclib) plus Letrozole

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Inclusion Criteria: *Histological confirmation of breast cancer with evidence of locally advanced or metastatic disease, which is not amenable to surgical resection or radiation therapy with curative intent. *Documented estrogen receptor (ER) and/or progesterone receptor (PR)-positive tumor *Documented HER2-negative tumor *Previously untreated with any systemic anticancer therapy for their locally advanced or metastatic disease. *Measurable disease or non-measurable bone only disease as defined by RECIST version 1.1

Exclusion criteria

Exclusion criteria: Exclusion Criteria: *In visceral crisis at risk of immediately life-threatening complications in the short term. *Current or past history of central nervous system metastases. *Have received prior (neo)adjuvant endocrine therapy (ET) and had recurrence during or within 12 months after the last dose of ET. *Have received prior (neo)adjuvant CDK4/6i and had recurrence during or within 12 months after the last dose of CDK4/6i. *Inadequate renal function, hepatic dysfunction, or hematologic abnormalities.

Design outcomes

Primary

Measure	Time frame
Progression Free Survival (PFS) by BICR [Time Frame: From the date of randomization until disease progression or death due to any cause (up to approximately 4 years)] -Time from the date of randomization to the date of the first documentation of objective progressive disease as determined by blinded independent central review (BICR) per RECIST v1.1, or death due to any cause, whichever occurs first	—

Measure

Time frame

Progression Free Survival (PFS) by BICR [Time Frame: From the date of randomization until disease progression or death due to any cause (up to approximately 4 years)] -Time from the date of randomization to the date of the first documentation of objective progressive disease as determined by blinded independent central review (BICR) per RECIST v1.1, or death due to any cause, whichever occurs first

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Secondary

Measure	Time frame
1. Overall Survival (OS) [Time Frame: From the date of randomization until death due to any cause (up to approximately 13 years).] -Time from the date of randomization to the date of death due to any cause 2. Progression Free Survival (PFS) by Investigator [Time Frame: From the date of randomization until disease progression or death due to any cause (up to approximately 4 years)] -Time from the date of randomization to the date of the first documentation of objective progressive disease as determined by investigator per RECIST v1.1, or death due to any cause, whichever occurs first 3. OR by BICR and by investigator [Time Frame: From randomization to progression or death whichever occurs first (up to approximately 4 years)] -Time from randomization date (every 8 weeks during the first 48 weeks and then every 12 weeks) to the date of progression OR death whichever occurs first 4. Duration of Response (DoR) by BICR and by investigator [Time Frame: From the date of CR or PR until objective progressive disease, or death (up to approximately 4 years)] -Time from the date of CR or PR to the first documentation of objective progressive disease, or death due to any cause, whichever occurs first 5. Incidence of treatment emergent treatment related adverse events (AE) [Time Frame: Duration of the study approximately up to 13 years.] -Incidence and severity of AEs graded according to the NCI CTCAE v5.0 6. Incidence of treatment emergent treatment related serious adverse events [Time Frame: Duration of the study approximately up to 13 years.] -Incidence and severity of AEs graded according to NCI CTCAE v5.0 7. Estimated mean change from baseline in EORTC QLQ C30 [Time Frame: Baseline to end of treatment (up to approximately 4 years)] 8. Estimated mean change from baseline in BPI-SF [Time Frame: Baseline to end of treatment (up to approximately 4 years)] 9. Estimated mean change from baseline in EQ-5D-5L [Time Frame: Baseline to end of treatment (up to approximately 4 ye	—

Measure

Time frame

1. Overall Survival (OS) [Time Frame: From the date of randomization until death due to any cause (up to approximately 13 years).] -Time from the date of randomization to the date of death due to any cause 2. Progression Free Survival (PFS) by Investigator [Time Frame: From the date of randomization until disease progression or death due to any cause (up to approximately 4 years)] -Time from the date of randomization to the date of the first documentation of objective progressive disease as determined by investigator per RECIST v1.1, or death due to any cause, whichever occurs first 3. OR by BICR and by investigator [Time Frame: From randomization to progression or death whichever occurs first (up to approximately 4 years)] -Time from randomization date (every 8 weeks during the first 48 weeks and then every 12 weeks) to the date of progression OR death whichever occurs first 4. Duration of Response (DoR) by BICR and by investigator [Time Frame: From the date of CR or PR until objective progressive disease, or death (up to approximately 4 years)] -Time from the date of CR or PR to the first documentation of objective progressive disease, or death due to any cause, whichever occurs first 5. Incidence of treatment emergent treatment related adverse events (AE) [Time Frame: Duration of the study approximately up to 13 years.] -Incidence and severity of AEs graded according to the NCI CTCAE v5.0 6. Incidence of treatment emergent treatment related serious adverse events [Time Frame: Duration of the study approximately up to 13 years.] -Incidence and severity of AEs graded according to NCI CTCAE v5.0 7. Estimated mean change from baseline in EORTC QLQ C30 [Time Frame: Baseline to end of treatment (up to approximately 4 years)] 8. Estimated mean change from baseline in BPI-SF [Time Frame: Baseline to end of treatment (up to approximately 4 years)] 9. Estimated mean change from baseline in EQ-5D-5L [Time Frame: Baseline to end of treatment (up to approximately 4 ye

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Countries

Argentina, Australia, Belgium, Brazil, Bulgaria, Canada, China, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, India, Ireland, Israel, Italy, Japan, Netherlands, Poland, Slovakia, South Korea, Spain, Sweden, Switzerland, Taiwan, Turkey, United Kingdom, United States

Contacts

Public ContactClinical Trials Information Desk

Pfizer R&D Japan G.K.

clinical-trials@pfizer.com+81-3-5309-7000

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Sep 19, 2026