A Study of PF-06873600 in People With Cancer

PHASE 1/2A DOSE ESCALATION AND EXPANSION STUDY EVALUATING SAFETY, TOLERABILITY, PHARMACOKINETIC, PHARMACODYNAMICS AND ANTI-TUMOR ACTIVITY OF PF-06873600 AS A SINGLE AGENT AND IN COMBINATION WITH ENDOCRINE THERAPY

The purpose of this clinical trial is to learn about the safety and effects of study medicine (PF-06873600) when taken alone or with hormone therapy by people with cancer.

People may be able to participate in this study if they have the following types of cancer: Hormone Receptor positive (HR+) breast cancer; Human Epidermal Growth Factor Receptor 2 (HER2)-negative breast cancer that is advanced or metastatic (spread to other parts of the body); triple negative breast cancer; epithelial ovarian cancer; fallopian tube cancer; or primary peritoneal cancer.

All participants in this study will receive the study medicine by mouth, 1 to 2 times a day at home. The dose of the study medicine may be changed during the study.

Some participants will also receive hormone therapy. The hormone therapy will be either letrozole by mouth once a day at home, or fulvestrant as a shot into the muscle. Fulvestrant will be given every two weeks at the study clinic for the first month, and then once a month after that.

Participants will take part in this study for at least 7 to 8 months, depending on how they respond to the therapy. During this time participants will visit the study clinic once a week for the first 2 cycles and every cycle thereafter.

Study Overview

• Status: Terminated
• Conditions: HR+ HER2- Metastatic Breast Cancer, Ovarian Cancer, Fallopian Tube Cancer, Primary Peritoneal Cancer, Triple Negative Breast Cancer, Male Breast Cancer
• Intervention / Treatment: Drug: PF-06873600; Drug: Endocrine Therapy 1; Drug: Endocrine Therapy 2

Detailed Description

This is a Phase 1/2a, open-label, multi-center, non-randomized, multiple dose, safety, tolerability, pharmacokinetic, and pharmacodynamic study of PF-06873600 administered as a single agent in sequential dose levels and then in combination with endocrine therapy. In Part 1A and Part 1C, successive cohorts of patients will receive escalating doses of PF-06873600 and then in dose finding (Part 1B) with PF-06873600 in combination with endocrine therapy (ET). This study contains 2 parts, dose escalation with single agent (Part 1A and 1C) and then dose finding with PF-06873600 in combination with endocrine therapy (Part 1B) followed by dose expansion arms of PF-06873600 in combination with endocrine therapy (Part 2).

• Study Type: Interventional
• Enrollment (Actual): 155
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• Bulgaria
  • Dobrich, Bulgaria, 9300
    • Multiprofile Hospital of Active Treatment - Dobrich AD
  • Haskovo, Bulgaria, 6300
    • Specialized Hospital for Active Treatment of Oncology - Haskovo EOOD
  • Plovdiv, Bulgaria, 4000
    • Complex Oncology Center -Plovdiv
• Canada
  • Quebec
    • Montreal, Quebec, Canada, H4A 3J1
      • McGill University Health Centre
• Japan
  • Chiba
    • Kashiwa, Chiba, Japan, 277-8577
      • National Cancer Center Hospital East
  • Kanagawa
    • Yokohama, Kanagawa, Japan, 2418515
      • Kanagawa cancer center
• Russia
  • Omsk, Russia, 644013
    • BIH of Omsk Region "Clinical Oncological Dispensary"
  • Omsk, Russia, 644046
    • BIH of Omsk Region "Clinical Oncological Dispensary"
  • Saint Petersburg, Russia, 191025
    • LLC "Medicina Severnoy Stolitsy"
  • Saint Petersburg, Russia, 192007
    • LLC "Severo-Zapadny Medical Center"
  • Sankt-Peterburg
    • Pushkin, Sankt-Peterburg, Russia, 196603
      • Private Medical Institution "Euromedservice"
• Ukraine
  • Kyiv, Ukraine, 03115
    • Communal nonprofit enterprise "Kyiv City Clinical Oncology Center" of Executive Body of Kyiv City
  • Lviv, Ukraine, 79031
    • Communal Noncommercial Enterprise of Lviv Regional Council "Lviv Oncological Regional Therapeutical
  • Dnipropetrovsk Oblast
    • Dnipro, Dnipropetrovsk Oblast, Ukraine, 49102
      • Municipal Non-profit Enterprise "City Clinical Hospital #4" of Dnipro City Council, "Dnipro State Me
  • Kharkivs’ka Oblast’
    • Kharkiv, Kharkivs’ka Oblast’, Ukraine, 61166
      • Kharkiv Regional Specialized Dispensary of Radiation Protection of the Population
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35233
      • University of Alabama at Birmingham
    • Birmingham, Alabama, United States, 35249
      • University of Alabama at Birmingham
  • Arizona
    • Scottsdale, Arizona, United States, 85258
      • Honorhealth
    • Scottsdale, Arizona, United States, 85258
      • Virginia G. Piper Cancer Center Pharmacy
  • Arkansas
    • Fayetteville, Arkansas, United States, 72703
      • Highlands Oncology Group
    • Rogers, Arkansas, United States, 72758
      • Highlands Oncology Group
    • Springdale, Arkansas, United States, 72762
      • Highlands Oncology Group
    • Springdale, Arkansas, United States, 72762
      • Highlands Oncology
  • California
    • Glendale, California, United States, 91204
      • The Oncology Institute of Hope and Innovation
    • Long Beach, California, United States, 90805
      • The Oncology Institute of Hope and Innovation
    • San Francisco, California, United States, 94143
      • UCSF Helen Diller Family Comprehensive Cancer Center
    • San Francisco, California, United States, 94158
      • UCSF Investigational Drugs Pharmacy
    • Santa Ana, California, United States, 92705
      • The Oncology Institute of Hope and Innovation
    • Santa Monica, California, United States, 90404
      • UCLA Hematology/Oncology - Santa Monica
    • Santa Monica, California, United States, 90404
      • UCLA Hematology/Oncology - Parkside
    • Whittier, California, United States, 90602
      • The Oncology Institute of Hope and Innovation
  • Colorado
    • Aurora, Colorado, United States, 80045
      • University of Colorado Hospital - Anschutz Cancer Pavilion (ACP)
    • Aurora, Colorado, United States, 80045
      • University of Colorado Hospital - Anschutz Outpatient Pavilion (AOP)
    • Aurora, Colorado, United States, 80045
      • University of Colorado Hospital - Anschutz Inpatient Pavilion (AIP)
    • Lone Tree, Colorado, United States, 80124
      • UCHealth Lone Tree Medical Center
  • Florida
    • Fort Lauderdale, Florida, United States, 33308
      • Holy Cross Hospital
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Dana-Farber Cancer Institute
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
    • Boston, Massachusetts, United States, 02215
      • Dana Farber Cancer Institute
    • Boston, Massachusetts, United States, 02115
      • Brigham & Women's Hospital
  • New York
    • Long Island City, New York, United States, 11101
      • Memorial Sloan Kettering Cancer Center
    • New York, New York, United States, 10065
      • Memorial Sloan Kettering Cancer Center
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Tennessee Oncology, PLLC
    • Nashville, Tennessee, United States, 37203
      • The Sarah Cannon Research Institute
    • Nashville, Tennessee, United States, 37203
      • The Sarah Cannon Research Institute-Pharmacy
  • Texas
    • Houston, Texas, United States, 77030
      • The University of Texas MD Anderson Cancer Center
    • San Antonio, Texas, United States, 78229
      • South Texas Accelerated Research Therapeutics, LLC
  • Washington
    • Federal Way, Washington, United States, 98003
      • Northwest Medical Specialties, PLLC
    • Gig Harbor, Washington, United States, 98332
      • Northwest Medical Specialties, PLLC
    • Puyallup, Washington, United States, 98373
      • Rainier Hematology-Oncology, PC
    • Puyallup, Washington, United States, 98373
      • Rainier Hematology-Oncology PC
    • Seattle, Washington, United States, 98195
      • University of Washington Medical Center
    • Seattle, Washington, United States, 98109
      • Fred Hutchinson Cancer Center
    • Tacoma, Washington, United States, 98405
      • Northwest Medical Specialties, PLLC

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Have a diagnosis of Hormone Receptor Positive (HR+), Human Epidermal Growth Factor Receptor 2 Negative (HER2-) breast cancer

  • Prior combined CDK 4/6 inhibitor and endocrine therapy and 1 or 2 prior lines of chemotherapy

• Have a diagnosis of metastatic triple negative breast cancer (TNBC)

  • Up to 1-2 prior lines of chemotherapy

• Have a diagnosis of advanced platinum resistant epithelial ovarian cancer (EOC)/fallopian tube cancer/primary peritoneal cancer (PPC)

  • Up to 2-3 prior lines of therapy

• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1
• Measurable disease or non-measurable disease and refractory to or intolerant of existing therapies (Part 1)
• Measurable disease as defined by RECIST 1.1 is required (Part 1B and Part 2 only)

Exclusion Criteria:

• Known active uncontrolled or symptomatic Central Nervous System (CNS) metastases
• Other active malignancy within 3 years prior to randomization, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ
• Major surgery or radiation within 4 weeks prior to study entry
• Last anti-cancer treatment within 2 weeks prior to study entry
• Participation in other studies involving investigational drug(s) within 4 weeks prior to study entry
• Pregnant or breastfeeding female patients
• Active inflammatory gastrointestinal (GI) disease, known diverticular disease or previous gastric resection or lap band surgery including impairment of gastro intestinal function or GI disease

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

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dose Escalation; Single Agent Dose Escalation	Drug: PF-06873600; PF-06873600 tablet for oral dosing
Experimental: Dose Finding Endocrine Therapy 1 Combination; Part 1B PF-06873600 plus Endocrine Therapy 1	Drug: PF-06873600; PF-06873600 tablet for oral dosing; Drug: Endocrine Therapy 1; Endocrine Therapy 1
Experimental: Dose Finding Endocrine Therapy 2 Combination; Part 1B PF-06873600 plus Endocrine Therapy 2	Drug: PF-06873600; PF-06873600 tablet for oral dosing; Drug: Endocrine Therapy 2; Endocrine Therapy 2
Experimental: Dose Expansion Arm A; PF-06873600 as a Single Agent	Drug: PF-06873600; PF-06873600 tablet for oral dosing
Experimental: Dose Expansion Arm B; PF-06873600 as a Single Agent in Various Tumor Types	Drug: PF-06873600; PF-06873600 tablet for oral dosing
Experimental: Dose Expansion Arm C; PF-06873600 in Combination with Endocrine Therapy 1	Drug: PF-06873600; PF-06873600 tablet for oral dosing; Drug: Endocrine Therapy 1; Endocrine Therapy 1
Experimental: Dose Expansion Arm D; PF-06873600 in Combination with Endocrine Therapy 1	Drug: PF-06873600; PF-06873600 tablet for oral dosing; Drug: Endocrine Therapy 1; Endocrine Therapy 1
Experimental: Dose Expansion Arm E; PF-06873600 in Combination with Endocrine Therapy 2	Drug: PF-06873600; PF-06873600 tablet for oral dosing; Drug: Endocrine Therapy 2; Endocrine Therapy 2

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Dose Limiting Toxicities (DLTs) - Part 1	DLT was defined as any of the following adverse events (AEs) occurring in the first cycle of treatment (28 days) which were attributable to one, the other, or both agents in the combination: Hematologic - grade(G) 4 neutropenia lasting >7 days; Febrile neutropenia defined as an absolute neutrophil count (ANC) <1.0 * 10^9/L with a single temperature of >38.3°C, or a sustained temperature of ≥38°C, for more than 1 hour; G≥3 neutropenia with associated infection; G3 thrombocytopenia with clinically significant bleeding as indicated by ≥ G2 bleeding; G4 thrombocytopenia. Nonhematologic: Confirmed case of Drug Induced Liver Injury (DILI) (Hy's Law); G≥3 AEs that were clinically significant.	Cycle 1 (within 28 days after the first dose of study intervention)
Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) - Part 1 + Part 2	An AE was defined as the appearance of (or worsening of any pre-existing) undesirable sign(s), symptom(s), or medical condition(s) that occurred after participants' signed informed consent has been obtained. An SAE was an AE resulting in any of the following outcomes: was fatal or life-threatening; resulted in persistent or significant disability/incapacity; constituted a congenital anomaly/birth defect; was medically significant; required inpatient hospitalization or prolongation of existing hospitalization. Treatment Related AEs were treatment emergent AEs with cause categorized by the investigator as related to study treatment.	Day 1 up to 28 days after the last dose of study intervention, up to approximately 24 months
Number of Participants With Worst Post-Baseline Hematology Results Based on Common Terminology Criteria for Adverse Events (CTCAE) Grade: Part 1 + Part 2	Severity was graded as NCI CTCAE version 4.03:Grade 1: asymptomatic or mild symptoms, clinical or diagnostic observations only, intervention not indicated; Grade 2: moderate, minimal, local or noninvasive intervention indicated, limiting age-appropriate instrumental activities of daily life (ADL); Grade 3: severe or medically significant but not immediately life-threatening, hospitalization or prolongation of existing hospitalization indicated, disabling, limiting self-care ADL; Grade 4: life-threatening consequence, urgent intervention indicated; Grade 5: death related to AE.	Day 1 up to 28 days after the last dose of study intervention, up to approximately 24 months
Number of Participants With Worst Post-Baseline Chemistry Results Based on Common Terminology Criteria for Adverse Events (CTCAE) Grade: Part 1 + Part 2	Severity was graded as NCI CTCAE version 4.03:Grade 1: asymptomatic or mild symptoms, clinical or diagnostic observations only, intervention not indicated; Grade 2: moderate, minimal, local or noninvasive intervention indicated, limiting age-appropriate instrumental activities of daily life (ADL); Grade 3: severe or medically significant but not immediately life-threatening, hospitalization or prolongation of existing hospitalization indicated, disabling, limiting self-care ADL; Grade 4: life-threatening consequence, urgent intervention indicated; Grade 5: death related to AE.	Day 1 up to 28 days after the last dose of study intervention, up to approximately 24 months
Number of Participants With Post-Baseline Vital Sign Abnormalities Meeting Pre-Defined Categorization - Part 1 + Part 2	Pre-defined criteria included: 1) systolic blood pressure (SBP) (mm Hg) minimum (min) value <90; 2) SBP change from baseline (CFB) (mm Hg) maximum (max) decrease >=30 or max increase >=30; 3) diastolic blood pressure (DBP) (mm Hg) min <50; 4) DBP CFB (mm Hg) max decrease >=20 or max increase >=20; 5) supine heart rate (HR) beats per minute (bpm) min <40 or max >120.	Day 1 up to 28 days after the last dose of study intervention, up to approximately 24 months
Number of Participants With Post-Baseline Electrocardiogram (ECG) Changes Meeting Pre-Defined Categorization - Part 1 + Part 2	ECG pre-defined categories for QTc interval adjusted according to Fridericia formula (QTcF) (msec) included: 450 <= max. <=480, 481 <= max. <=500, max >=501; QTcF CFB: 30 < max <=60, max >60; for PR and QRS: PR (msec): max >=300; PR increase from baseline: Baseline >200 and max. >=25% increase, Baseline <=200 and max. >=50% increase; QRS (msec): max >=200; QRS (msec) increase from baseline: Baseline >100 and max. >=25% increase, Baseline <=100 and max. >=50% increase. Categories, with at least 1 participant having ECG abnormality in any of the reporting arms, were reported in this outcome measure.	Day 1 up to 28 days after the last dose of study intervention, up to approximately 24 months
Overall Response Rate (ORR): Part 2	ORR: percentage of participants with confirmed complete response (CR) or partial response (PR). Response evaluation criteria in solid tumors (RECIST) v1.1: a) CR = disappearance of all non-nodal target lesions. In addition, any pathological lymph nodes assigned as target lesions that had a reduction in short axis to less than (<) 10 millimeter (mm). Disappearance of all non-target lesions. In addition, all lymph nodes assigned a non-target lesion must be non-pathological in size (<10 mm short axis) and b) PR = at least a 30 percent (%) decrease in the sum of diameter of all target lesions, taking as reference the baseline sum of diameters. Any radiological assessments taken more than 30 days after the last dose of study therapy or after antineoplastic agents other than study treatments taken by the participants was excluded from the best overall response derivation. Confirmation of CR or PR was to be at least 4 weeks apart from the previous radiological assessment.	From the start of the treatment until disease/clinical progression or death or early study discontinuation, whichever happened earlier (approximately up to 24 months)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Observed Plasma Concentration (Cmax) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1 + Part 2	The maximum observed concentration of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B and Part 2) was reported. The Cmax value was observed directly from data.	Part 1: pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on Cycle 1 Day 1 (C1D1); Part 2: pre-dose, 1, 2, 4, 6 hours post-dose on C1D1
Time to Reach Cmax at Steady State (Tmax) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1 + Part 2	Tmax of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B and Part 2) was reported.	Part 1: pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1; Part 2: pre-dose, 1, 2, 4, 6 hours post-dose on C1D1
Area Under the Concentration-Time Profile From Time 0 to the Time of the Last Quantifiable Concentration (AUClast) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1	AUClast of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported.	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1
Area Under the Concentration-Time Profile From Time 0 Extrapolated to Infinite Time (AUCinf) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1	AUCinf of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported.	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1
Apparent Clearance (CL/F) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1	CL/F of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported.	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1
Apparent Volume of Distribution (Vz/F) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1	Vz/F of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported.	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1
Terminal Half-life (t1/2) of PF-06873600 Following a Single Oral Dose of Study Intervention on Cycle 1 Day 1 - Part 1	t1/2 of PF-06873600 after single dose of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported.	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D1
Steady State Maximum Concentration (Css,Max) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1 + Part 2	Css,max of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B and Part 2) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Part 1: pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15; Part 2: pre-dose, 1, 2, 4, 6 hours post-dose on C1D15
Time to Maximum Plasma Concentration at Steady State (Tss,Max) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1 + Part 2	Tss,max of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B and Part 2) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Part 1: pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15; Part 2: pre-dose, 1, 2, 4, 6 hours post-dose on C1D15
Steady State Minimum Plasma Concentration (Css,Min) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1 + Part 2	Css,min of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B and Part 2) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Part 1: pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15; Part 2: pre-dose, 1, 2, 4, 6 hours post-dose on C1D15
Steady-State Area Under the Plasma Concentration Versus Time Curve Within One Dose Interval (AUCss,Tau) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1	AUCss,tau of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15
Steady-State Apparent Oral Plasma Clearance (CLss/F) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1	CLss/F of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15
Apparent Volume of Distribution at Steady State (Vss/F) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1	Vss/F of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15
Accumulation Ratio Based on AUC (Rac) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 1	Rac of PF-06873600 after multiple doses of study intervention when given as a single agent (Part 1A and Part 1C), in combination with letrozole, and in combination with fulvestrant (Part 1B) was reported. Multiple-dose PK parameters were not calculated for the modified release selection cohort in Part 1C (ie, the group "Part 1C PF-06873600 MR 20 IR 25 mg BID").	Pre-dose, 0.25, 0.5, 1, 2, 3, 4, 6, 12 hours post-dose on C1D15
Accumulation Ratio Based on Cmax (Observed) (Rac,Cmax) of PF-06873600 Following Multiple Doses of Study Intervention on Cycle 1 Day 15 - Part 2	Rac,cmax of PF-06873600 after multiple doses of study intervention when given as in combination with fulvestrant (Part 2) was reported.	Pre-dose, 1, 2, 4, 6 hours post-dose on C1D15
Pharmacodynamic (PD) Biomarker Phospho-retinoblastoma Protein (pRb) in Tumor Tissue in Participants - Part 1 + Part 2	Level of the PD marker, pRb, was analyzed at 2 time points, at screening and at Cycle 2 Day 1. Percentage changes of pRb at Cycle 2 Day 1 from screening (baseline) were calculated.	Screening and Cycle 2 Day 1
PD Biomarker Ki67 in Tumor Tissue in Participants - Part 1 + Part 2	Level of the PD marker, Ki67, was analyzed at 2 time points, at screening and at Cycle 2 Day 1. Percent changes of pRb at Cycle 2 Day 1 from screening (baseline) were calculated.	Screening and Cycle 2 Day 1

Collaborators and Investigators

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

Publications and helpful links

Helpful Links

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

Study record dates

Study Major Dates

• Study Start (Actual): March 7, 2018
• Primary Completion (Actual): April 5, 2023
• Study Completion (Actual): October 30, 2024

Study Registration Dates

• First Submitted: February 22, 2018
• First Submitted That Met QC Criteria: April 25, 2018
• First Posted (Actual): May 8, 2018

Study Record Updates

• Last Update Posted (Estimated): November 14, 2025
• Last Update Submitted That Met QC Criteria: October 27, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: Fallopian tube cancer; Triple negative breast cancer (TNBC); Advanced breast cancer; Goserelin; Metastatic breast cancer (MBC); CDK4/6 inhibitor; Epithelial ovarian cancer (EOC); Leuprolide acetate; Hormone Receptor (HR) Positive Breast Cancer; Estrogen receptor (ER) positive; Progesterone receptor (PR) positive; Cyclin-dependent kinase (CDK); Human epidermal growth factor receptor 2 (HER2) negative; Primary peritoneal cancer (PPC); Endocrine Therapy (ET); Measurable disease; Luteinizing Hormone Releasing Hormone (LHRH) Agonist
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Endocrine System Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Neoplasms by Histologic Type; Genital Diseases, Female; Endocrine Gland Neoplasms; Neoplasms, Glandular and Epithelial; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Skin Diseases; Breast Diseases; Carcinoma; Fallopian Tube Diseases; Skin and Connective Tissue Diseases; Carcinoma, Ovarian Epithelial; Ovarian Neoplasms; Breast Neoplasms; Triple Negative Breast Neoplasms; Fallopian Tube Neoplasms; Breast Neoplasms, Male
• Other Study ID Numbers: C3661001; NCT03519178 (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