Study of PF-07248144 in Advanced or Metastatic Solid Tumors (KAT6)

A PHASE 1/2A DOSE ESCALATION AND EXPANSION STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETIC, PHARMACODYNAMIC, AND ANTI-TUMOR ACTIVITY OF PF-07248144 IN PARTICIPANTS WITH ADVANCED OR METASTATIC SOLID TUMORS

This is an open-label, multi center study to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-07248144 and early signs of clinical efficacy of PF-07248144 as a single agent and in combination with other agents

Study Overview

• Status: Recruiting
• Conditions: Locally Advanced or Metastatic ER+ HER2- Breast Cancer; Locally Advanced or Metastatic Castration-resistant Prostate Cancer; Locally Advanced or Metastatic Non-small Cell Lung Cancer
• Intervention / Treatment: Drug: PF-07220060; Drug: PF-07248144; Drug: Fulvestrant; Drug: Letrozole; Drug: Palbociclib; Drug: PF-07850327, ARV-471, vepdegestrant

Detailed Description

Study has two parts, Part 1 (dose escalation) and Part 2 (dose expansion). Part 1 is divided into Parts 1A, 1B, 1C, 1D and 1E and Part 2 is divided into Parts 2A, 2B, 2D and 2E. In Part 1A, single escalating doses of PF-07248144 alone will be administered to determine the maximum tolerable dose (MTD) and select the recommended dose for expansion (RDE). In Part 1B, 1C, 1D and 1E PF-07248144 will be administered in combination with either fulvestrant (Part 1B); palbociclib + letrozole (Part 1C) or PF-07220060+fulvestrant (Part 1D) or vepdegestrant (Part 1E). After the determination of the monotherapy RDE in Part 1A, PF-07248144 will be evaluated in a dose expansion cohort as a monotherapy in Part 2A.

After determination of the combination RDE from Part 1B, PF-07248144 in combination with fulvestrant, PF-07248144 will be evaluated in a combination dose expansion with fulvestrant in Part 2B. In Part 1C, PF-07248144 in combination with letrozole + palbociclib will be evaluated for dose finding to determine the MTD and RDE for this combination. After determination of the triple combination RDE from Part 1D, PF-07248144 in combination with PF-07220060 + fulvestrant will be evaluated in a combination dose-expansion cohort, Part 2D. After determination of the combination RDE from Part 1E, PF-07248144 in combination with vepdegestrant will be evaluated in a combination dose-expansion cohort, Part 2E.

• Study Type: Interventional
• Enrollment (Estimated): 320
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Study Locations

• Australia
  • New South Wales
    • Camperdown, New South Wales, Australia, 2050
      • Terminated
      • Chris O'Brien Lifehouse
  • South Australia
    • Adelaide, South Australia, Australia, 5000
      • Recruiting
      • Cancer Research South Australia
  • Victoria
    • Melbourne, Victoria, Australia, 3000
      • Recruiting
      • Peter Maccallum Cancer Centre
    • Parkville, Victoria, Australia, 3050
      • Recruiting
      • Royal Melbourne Hospital
    • St Albans, Victoria, Australia, 3021
      • Recruiting
      • Western Health-Sunshine & Footscray Hospitals
  • Western Australia
    • Subiaco, Western Australia, Australia, 6008
      • Recruiting
      • St. John of God Subiaco Hospital
• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100142
      • Recruiting
      • Beijing Cancer Hospital
  • Guangdong
    • Guangzhou, Guangdong, China, 510060
      • Recruiting
      • Sun Yat-sen University Cancer Center
  • Jilin
    • Changchun, Jilin, China, 130000
      • Recruiting
      • Jilin Province Tumor Hospital
    • Changchun, Jilin, China, 132000
      • Recruiting
      • Jilin Province Tumor Hospital
  • Shaanxi
    • Xi'an, Shaanxi, China, 710061
      • Recruiting
      • The First Affiliated Hospital of Xi'an Jiaotong University
• Japan
  • Aichi-ken
    • Nagoya, Aichi-ken, Japan, 464-8681
      • Recruiting
      • Aichi Cancer Center Hospital
  • Chiba
    • Kashiwa, Chiba, Japan, 277-8577
      • Recruiting
      • National Cancer Center Hospital East
  • Kanagawa
    • Yokohama, Kanagawa, Japan, 2418515
      • Recruiting
      • Kanagawa Cancer Center
  • Tokyo
    • Chuo-ku, Tokyo, Japan, 104-0045
      • Recruiting
      • National Cancer Center Hospital
• South Korea
  • Seoul, South Korea, 05505
    • Recruiting
    • Asan Medical Center
  • Gyeonggi-do
    • Seongnam-si, Gyeonggi-do, South Korea, 13620
      • Recruiting
      • Seoul National University Bundang Hospital
  • Seoul-teukbyeolsi [seoul]
    • Seoul, Seoul-teukbyeolsi [seoul], South Korea, 03080
      • Recruiting
      • Seoul National University Hospital
    • Seoul, Seoul-teukbyeolsi [seoul], South Korea, 06351
      • Recruiting
      • Samsung Medical Center
    • Seoul, Seoul-teukbyeolsi [seoul], South Korea, 03722
      • Recruiting
      • Severance Hospital, Yonsei University Health System
  • Taegu-kwangyǒkshi
    • Daegu, Taegu-kwangyǒkshi, South Korea, 41404
      • Recruiting
      • Kyungpook National University Chilgok Hospital
• United States
  • Arizona
    • Scottsdale, Arizona, United States, 85258
      • Terminated
      • HonorHealth
  • California
    • Los Angeles, California, United States, 90048
      • Recruiting
      • Cedars Sinai Medical Center
    • Los Angeles, California, United States, 90048
      • Recruiting
      • Cedars-Sinai Cancer at Cedars-Sinai Medical Center
    • San Francisco, California, United States, 94158
      • Recruiting
      • UCSF Medical Center at Mission Bay
  • Connecticut
    • New Haven, Connecticut, United States, 06511
      • Recruiting
      • Yale University
    • New Haven, Connecticut, United States, 06510
      • Recruiting
      • Smilow Cancer Hospital at Yale - New Haven
    • New Haven, Connecticut, United States, 06511
      • Recruiting
      • Smilow Cancer Hospital Phase 1 Unit
    • New Haven, Connecticut, United States, 06510
      • Recruiting
      • Yale-New Haven Hospital- Yale Cancer Center
  • Florida
    • Fort Lauderdale, Florida, United States, 33308
      • Terminated
      • Holy Cross Hospital
  • Kentucky
    • Edgewood, Kentucky, United States, 41017
      • Recruiting
      • St. Elizabeth Healthcare
    • Louisville, Kentucky, United States, 40202
      • Recruiting
      • University of Louisville
    • Louisville, Kentucky, United States, 40202
      • Recruiting
      • University Medical Center, lnc.:DBA University of Louisville Hospital
    • Louisville, Kentucky, United States, 40202
      • Recruiting
      • UofL Health Brown Cancer Center
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Recruiting
      • SCRI Oncology Partners
  • Texas
    • Conroe, Texas, United States, 77384
      • Recruiting
      • MD Anderson The Woodlands
    • Houston, Texas, United States, 77079
      • Recruiting
      • MD Anderson West Houston
    • Houston, Texas, United States, 77030
      • Recruiting
      • The University of Texas M. D. Anderson Cancer Center
    • Houston, Texas, United States, 77030
      • Recruiting
      • U.T. MD Anderson Cancer Center
    • League City, Texas, United States, 77573
      • Recruiting
      • MD Anderson League City
    • San Antonio, Texas, United States, 78229
      • Recruiting
      • NEXT Oncology
    • Sugar Land, Texas, United States, 77478
      • Recruiting
      • MD Anderson
  • Washington
    • Seattle, Washington, United States, 98104
      • Recruiting
      • Swedish Cancer Institute
    • Seattle, Washington, United States, 98122
      • Recruiting
      • Swedish Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Disease Characteristics - Breast, Prostate, and Lung Cancer
• Part 1A (Monotherapy Dose Escalation) Histological or cytological diagnosis of locally advanced or metastatic ER+HER2- breast cancer, CRPC, or NSCLC that is intolerant or resistant to standard therapy or for which no standard therapy is available.
• Part 1B, Part 1C, Part 1D and Part 1E (Combination Dose Escalation) Histological or cytological diagnosis of locally advanced or metastatic ER+HER2- breast cancer. Participants must have progressed after at least 1 prior line of treatment with an endocrine therapy and CDK4/6 inhibitor in the advanced or metastatic setting.
• Part 2A (ER+HER2- breast cancer 2L+, monotherapy) Histological or cytological diagnosis of locally advanced or metastatic ER+HER2- breast cancer. Participants must have progressed after at least 1 prior line of CDK4/6 inhibitor and 1 line of endocrine therapy.
• Part 2B (ER+HER2- breast cancer 2-4L, combination with fulvestrant) Histological or cytological diagnosis of advanced or metastatic ER+HER2- breast cancer. Participants must have progressive disease after at least 1 prior line of a CDK4/6 inhibitor and at least 1 prior line of endocrine therapy.. Participants must not have received more than 3 prior lines of systemic therapies including up to 1 line of cytotoxic chemotherapy for visceral disease in advanced or metastatic setting; Participants may have but are not required to have prior treatment with fulvestrant.
• Part 2D (ER+HER2- breast cancer 2-4L, combination with PF-07220060 (CDK4i) and fulvestrant):

Histological or cytological diagnosis of advanced or metastatic ER+HER2- breast cancer. Participants must have progressive disease after at least 1 prior line of a CDK4/6 inhibitor and at least 1 prior line of endocrine therapy.

• Participants must have not received more than 3 lines of systemic therapies including up to 1 line of cytotoxic chemotherapy for visceral disease in advanced or metastatic setting; Participants may have but are not required to have prior treatment with fulvestrant.
• Part 2E (ER+HER2- breast cancer 2-4L, combination with vepdegestrant): Histological or cytological diagnosis of advanced or metastatic ER+HER2- breast cancer. Participants must have progressive disease after at least 1 prior line of a CDK4/6 inhibitor and at least 1 prior line of endocrine therapy; Participants must have not received more than 3 lines of systemic therapies including up to 1 line of cytotoxic chemotherapy for visceral disease in advanced or metastatic setting; Participants may have received fulvestrant
• Participants with ER+HER2- advanced or metastatic breast cancer must have documentation of ER-positive tumor (≥1% positive stained cells) based on most recent tumor biopsy utilizing an assay consistent with local standards.
• Participants with ER+HER2- advanced or metastatic breast cancer must have documentation of HER2-negative tumor: HER2-negative tumor is determined as immunohistochemistry score 0/1+ or negative by in situ hybridization (FISH/CISH/SISH/DISH) defined as a HER2/CEP17 ratio <2 or for single probe assessment a HER2 copy number <4.
• Female participants with ER+HER2- advanced or metastatic breast cancer considered to be of childbearing potential (or have tubal ligations only) must be willing to undergo medically induced menopause by treatment with the approved LHRH agonist such as goserelin, leuprolide or equivalent agents to induce chemical menopause.
• Female participants with ER+HER2- advanced or metastatic breast cancer of nonchildbearing potential must meet at least 1 criteria of achieving postmenopausal status.
• Participants must have at least 1 measurable lesion as defined by RECIST version 1.1 that has not been previously irradiated.
• Eastern Cooperative Oncology Group (ECOG) Performance Status PS 0 or 1
• Female or male patients aged ≥ 18 years (Japan ≥ 20 years) (South Korea ≥ 19 years).
• Adequate renal, liver, and bone marrow function.
• Resolved acute effects of any prior therapy to baseline severity or CTCAE Grade 1 except for adverse events (AEs) not constituting a safety risk by investigator judgment.

Exclusion Criteria:

• Unmanageable ascites (limited medical treatment to control ascites is permitted, but all participants with ascites require review by sponsor's medical monitor).
• Participants with any other active malignancy within 3 years prior to enrollment, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ.
• Major surgery, radiation therapy, or systemic anti-cancer therapy within 3 weeks prior to study entry.
• Prior irradiation to >25% of the bone marrow.
• ECG clinically relevant abnormalities (eg, QTc >470 msec, complete LBBB, second/third degree AV block, ST elevation or EKG changes suggesting myocardial infarction or active myocardia ischemia).
• Therapeutic anticoagulation. However, low molecular weight heparin is allowed. Vitamin K antagonists or factor Xa inhibitors may be allowed following discussion with the Sponsor.
• Known or suspected hypersensitivity or severe allergy to active ingredient/excipients of PF-07248144.
• Active inflammatory GI disease, refractory and unresolved chronic diarrhea or previous gastric resection, lap band surgery or other GI conditions and surgeries that may significantly alter the absorption of PF-07248144 tablets. Gastroesophageal reflux disease under treatment is allowed.
• Pregnant or breastfeeding female participants.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

10

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 2A Monotherapy Dose Expansion Arm; PF-07248144 Monotherapy Dose Expansion	Drug: PF-07248144; KAT6 Inhibitor
Experimental: 2B Combination Dose Expansion Arm; PF-07248144 with Fulvestrant Dose Expansion	Drug: PF-07248144; KAT6 Inhibitor; Drug: Fulvestrant; Endocrine Therapy; Other Names: Faslodex
Experimental: 1A Monotherapy Dose Escalation; PF-07248144 Monotherapy Escalation	Drug: PF-07248144; KAT6 Inhibitor
Experimental: 1B Combination Dose Escalation; PF-07248144 with Fulvestrant Combination Dose Escalation	Drug: PF-07248144; KAT6 Inhibitor; Drug: Fulvestrant; Endocrine Therapy; Other Names: Faslodex
Experimental: 1C Combination Dose Escalation; PF-07248144 with Letrozole + Palbociclib Combination Dose Escalation	Drug: PF-07248144; KAT6 Inhibitor; Drug: Letrozole; Endocrine Therapy; Other Names: Femara; Drug: Palbociclib; CDK4/6 Inhibitor; Other Names: Ibrance
Experimental: 1D Combination Dose Escalation; PF-07248144 with PF-07220060 +Fulvestrant	Drug: PF-07220060; CDK4 inhibitor; Drug: PF-07248144; KAT6 Inhibitor; Drug: Fulvestrant; Endocrine Therapy; Other Names: Faslodex
Experimental: 2D Combination Dose Expansion Arm; PF-07248144 with PF-07220060 +Fulvestrant Dose Expansion	Drug: PF-07220060; CDK4 inhibitor; Drug: PF-07248144; KAT6 Inhibitor; Drug: Fulvestrant; Endocrine Therapy; Other Names: Faslodex
Experimental: China Monotherapy Dose Expansion; PF-07248144 Monotherapy Dose Expansion	Drug: PF-07248144; KAT6 Inhibitor
Experimental: 1E Combination Dose Escalation; PF-07248144 with Vepdegestrant Combination Dose Escalation	Drug: PF-07248144; KAT6 Inhibitor; Drug: PF-07850327, ARV-471, vepdegestrant; PROTAC (PROteolysis Targeting Chimera) ER degrader
Experimental: 2E Combination Dose Expansion Arm; PF-07248144 with Vepdegestrant Combination Dose Expansion	Drug: PF-07248144; KAT6 Inhibitor; Drug: PF-07850327, ARV-471, vepdegestrant; PROTAC (PROteolysis Targeting Chimera) ER degrader

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with dose-limiting toxicities in the Dose Escalation Arms.	Dose-limiting toxicities (DLTs)	Up to 29 days
Safety and Tolerability as assessed by adverse event monitoring for participants enrolled in the Dose Escalation Arms.	Adverse Events as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness, and relationship to study therapy.	Up to 24 months
Safety and Tolerability through monitoring of laboratory assessments for participants enrolled in the Dose Escalation Arms.	Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), and timing.	Up to 24 months
Safety and Tolerability as assessed by adverse event monitoring for participants enrolled in the Dose Expansion Arms	Adverse Events as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness, and relationship to study therapy.	Up to 24 months
Safety and Tolerability through monitoring of laboratory assessments for participants enroled in the Dose Expansion Arms	Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), and timing.	Up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Palbociclib trough concentrations at steady instate (Cmin,ss) in the 1C combination dose finding arm.	Pharmacokinetic (PK) assessment for palbociclib exposure.	Up to 24 months
Maximum Observed Concentration (Cmax) in the participants in the food effect subset in monotherapy dose expansion arm	The effect of food on the PK of PF-07248144.	Cycle 1 Day -7 and Cycle 1 Day 1 (each cycle is 28 days)
Time to Maximum concentration (Tmax) in the participants in the food effect subset in monotherapy dose expansion arm	The effect of food on the PK of PF-07248144.	Cycle 1 Day -7 and Cycle 1 Day 1 (each cycle is 28 days)
AUC from time zero to time of last measurable concentration (AUClast) in the participants in the food effect subset in monotherapy dose expansion arm	The effect of food on the PK of PF 07248144.	Cycle 1 Day -7 and Cycle 1 Day 1 (each cycle is 28 days)
Amount of PF-07248144 excreted in urine relative to dose administered (%) in a sub-set of participants in monotherapy dose expansion arm.	Evaluate urine pharmacokinetic (PK) of PF-07248144.	Up to 24 months
Renal clearance (CLr) in a sub-set of participants in monotherapy dose expansion arm	Evaluate urine pharmacokinetic (PK) of PF-07248144.	Up to 24 months
Progression Free Survival (PFS) observed in participants in the Dose Expansion Arms		Up to 24 months
Time to Progression (TTP) observed in participants enrolled in the Dose Expansion Arms		Up to 24 months
Overall survival (OS) observed in participants enrolled in Dose Expansion Arms		Up to 24 months
Best Overall Response (BOR) observed in participants in the dose expansion arms		Up to 24 months
Duration of Response (DOR) observed in participants in the dose expansion arms		up to 24 months
Clinical Benefit Rate (CBR) observed in participants in the Dose Expansion Arms		up to 24 months
Single Dose: Maximum Observed Concentration (Cmax) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Single Dose: Time to Maximum concentration (Tmax) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Single Dose: AUC from time zero to time of last measurable concentration (AUClast) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Single and Multiple Dose: Terminal Elimination half-life (t1/2) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Multiple Dose: Steady-State Cmax (Cmax,ss) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Multiple Dose: Steady-state Tmax (Tmax,ss) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Multiple Dose: Steady state AUC during a dosage interval (τ) (AUCτ,ss) in the Dose Escalation and Dose Finding Arms	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Multiple Dose: Steady-state Cmin (Cmin,ss) in the Dose Escalation and Dose Finding Arms.	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Multiple Dose: Steady-state apparent total clearance (CLss/F) in the Dose Escalation and Dose Finding Arms.	Pharmacokinetic (PK) assessments for PF-07248144, PF-07220060 (Part 1D) and vepdegestrant and ARV-473 (Part 1E)	Up to 24 months
Peak concentrations of PF-07248144, PF-07220060 (Part 2D) and vepdegestrant and ARV-473 (Part 2E) for selected cycles in the Dose Expansion Arms	Pharmacokinetic (PK) assessment for PF-07248144, PF-07220060 (Part 2D) and vepdegestrant and ARV-473 (Part 2E)	Up to 24 months
Trough concentrations of PF-07248144 for selected cycles in the Dose Expansion Arms	Pharmacokinetic (PK) assessment for PF-07248144 , PF-07220060 (Part 2D) and vepdegestrant and ARV-473 (Part 2E)	Up to 24 months

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

General Publications

• Mukohara T, Park YH, Sommerhalder D, Yonemori K, Hamilton E, Kim SB, Kim JH, Iwata H, Yamashita T, Layman RM, Mita M, Clay T, Chae YS, Oakman C, Yan F, Kim GM, Im SA, Lindeman GJ, Rugo HS, Liyanage M, Saul M, Le Corre C, Skoura A, Liu L, Li M, LoRusso PM. Inhibition of lysine acetyltransferase KAT6 in ER+HER2- metastatic breast cancer: a phase 1 trial. Nat Med. 2024 Aug;30(8):2242-2250. doi: 10.1038/s41591-024-03060-0. Epub 2024 Jun 1.
• Bishop TR, Subramanian C, Bilotta EM, Garnar-Wortzel L, Ramos AR, Zhang Y, Asiaban JN, Ott CJ, Rock CO, Erb MA. Acetyl-CoA biosynthesis drives resistance to histone acetyltransferase inhibition. Nat Chem Biol. 2023 Oct;19(10):1215-1222. doi: 10.1038/s41589-023-01320-7. Epub 2023 May 1.

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2020
• Primary Completion (Estimated): July 13, 2029
• Study Completion (Estimated): August 10, 2029

Study Registration Dates

• First Submitted: October 5, 2020
• First Submitted That Met QC Criteria: October 22, 2020
• First Posted (Actual): October 28, 2020

Study Record Updates

• Last Update Posted (Actual): April 16, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Solid tumors
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Respiratory Tract Diseases; Lung Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Lung Neoplasms; Carcinoma, Bronchogenic; Bronchial Neoplasms; Carcinoma, Non-Small-Cell Lung; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Polycyclic Compounds; Steroids; Fused-Ring Compounds; Nitriles; Estradiol; Estrenes; Estranes; Estradiol Congeners; Gonadal Steroid Hormones; Gonadal Hormones; Triazoles; Letrozole; Fulvestrant; palbociclib
• Other Study ID Numbers: C4551001; NCT04606446 (Registry Identifier: ClinicalTrials.gov)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No