^
    2ms
    C4391002: A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1/2, N=192, Active, not recruiting, Pfizer | Recruiting --> Active, not recruiting | Trial completion date: Dec 2026 --> Aug 2026 | Trial primary completion date: Dec 2026 --> Aug 2026
    Enrollment closed • Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive • PTEN mutation + HR positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    3ms
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=337, Recruiting, Pfizer | Trial completion date: May 2028 --> Nov 2027 | Trial primary completion date: Mar 2027 --> Sep 2026
    Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    4ms
    A Study for Multiple Tablet Forms of The Study Medicine (PF-07220060) in Healthy Adults (clinicaltrials.gov)
    P1, N=113, Completed, Pfizer | Active, not recruiting --> Completed
    Trial completion
    |
    atirmociclib (PF-07220060)
    4ms
    A Study to Learn About the Study Medicine PF-07220060 Together With Letrozole Compared to Letrozole Alone in Women Post Menopause (clinicaltrials.gov)
    P2, N=118, Recruiting, Pfizer | Not yet recruiting --> Recruiting
    Enrollment open
    |
    letrozole • atirmociclib (PF-07220060)
    4ms
    A Study for Multiple Tablet Forms of The Study Medicine (PF-07220060) in Healthy Adults (clinicaltrials.gov)
    P1, N=112, Active, not recruiting, Pfizer | Recruiting --> Active, not recruiting
    Enrollment closed
    |
    atirmociclib (PF-07220060)
    4ms
    Longitudinal circulating tumor DNA (ctDNA) dynamics in phase I/IIa study of the first-in-class CDK4-selective inhibitor, PF-07220060, in combination with endocrine therapy in patients with HR+/HER2− metastatic breast cancer (mBC) who progressed on prior CDK4/6 inhibitors (ESMO 2024)
    We present data from the exploratory ctDNA analysis of the study. ctDNA samples were collected at baseline (cycle 1, day 1 [C1D1]), C1D15 and end-of-treatment (EOT) in patients (pts) with HR+/HER2− mBC treated with oral 300 or 400 mg BID PF-07220060, with fulvestrant (Part 1B, n=18) or letrozole (Part 1C, n=15) and analyzed with the Guardant360 platform (Guardant Health). Longitudinal ctDNA profiling enabled the identification of key genetic alterations and demonstrated that PF-07220060 plus ET may benefit pts with or without ESR1 and PI3K pathway mutations. Early ctDNA MR trended with favorable clinical outcomes, while pts with undetectable ctDNA on treatment had improved PFS.
    Combination therapy • P1/2 data • Clinical • Circulating tumor DNA • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • TP53 (Tumor protein P53) • PIK3CA (Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha) • PTEN (Phosphatase and tensin homolog) • AKT1 (V-akt murine thymoma viral oncogene homolog 1)
    |
    Guardant360® CDx
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)
    5ms
    A Study to Learn About the Study Medicine PF-07220060 Together With Letrozole Compared to Letrozole Alone in Women Post Menopause (clinicaltrials.gov)
    P2, N=118, Not yet recruiting, Pfizer
    New P2 trial
    |
    letrozole • atirmociclib (PF-07220060)
    5ms
    A Study for Multiple Tablet Forms of The Study Medicine (PF-07220060) in Healthy Adults (clinicaltrials.gov)
    P1, N=112, Recruiting, Pfizer | N=84 --> 112 | Trial completion date: Mar 2024 --> Jul 2024 | Trial primary completion date: Feb 2024 --> Jun 2024
    Enrollment change • Trial completion date • Trial primary completion date
    |
    atirmociclib (PF-07220060)
    6ms
    A Study to Understand What the Body Does to the Study Medicine Called PF-07220060 When Taken by Healthy Adults (clinicaltrials.gov)
    P1, N=12, Completed, Pfizer | Active, not recruiting --> Completed
    Trial completion
    |
    atirmociclib (PF-07220060)
    7ms
    A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1/2, N=240, Recruiting, Pfizer | Trial completion date: Sep 2026 --> Dec 2026 | Trial primary completion date: Sep 2026 --> Dec 2026
    Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive • PTEN mutation + HR positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    7ms
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=337, Recruiting, Pfizer | Trial completion date: Oct 2027 --> May 2028 | Trial primary completion date: Aug 2026 --> Mar 2027
    Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive • PTEN mutation + HR positive
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    8ms
    A Study to Understand What the Body Does to the Study Medicine Called PF-07220060 When Taken by Healthy Adults (clinicaltrials.gov)
    P1, N=12, Active, not recruiting, Pfizer | Recruiting --> Active, not recruiting
    Enrollment closed
    |
    atirmociclib (PF-07220060)
    9ms
    A Study to Learn About Vepdegestrant When Given With PF-07220060 to People With Advanced or Metastatic Breast Cancer. (clinicaltrials.gov)
    P1/2, N=65, Recruiting, Pfizer | Not yet recruiting --> Recruiting | Trial completion date: Nov 2026 --> Feb 2026 | Trial primary completion date: May 2026 --> Aug 2025
    Enrollment open • Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    vepdegestrant (ARV-471) • atirmociclib (PF-07220060)
    9ms
    A Study to Learn About the Study Medicine Called PF-07220060 in Combination With Fulvestrant in People With HR-positive, HER2-negative Advanced or Metastatic Breast Cancer Who Progressed After a Prior Line of Treatment (clinicaltrials.gov)
    P3, N=510, Recruiting, Pfizer | Not yet recruiting --> Recruiting
    Enrollment open • Combination therapy • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • PGR (Progesterone receptor)
    |
    HER-2 negative
    |
    everolimus • fulvestrant • exemestane • atirmociclib (PF-07220060)
    9ms
    A Study to Understand What the Body Does to the Study Medicine Called PF-07220060 When Taken by Healthy Adults (clinicaltrials.gov)
    P1, N=12, Recruiting, Pfizer
    New P1 trial
    |
    atirmociclib (PF-07220060)
    10ms
    A Study to Learn About Vepdegestrant When Given With PF-07220060 to People With Advanced or Metastatic Breast Cancer. (clinicaltrials.gov)
    P1/2, N=65, Not yet recruiting, Pfizer
    New P1/2 trial • Combination therapy • Metastases
    |
    vepdegestrant (ARV-471) • atirmociclib (PF-07220060)
    12ms
    A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1/2, N=240, Recruiting, Pfizer | Phase classification: P1b/2 --> P1/2
    Phase classification • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    1year
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=337, Recruiting, Pfizer | Trial completion date: Feb 2026 --> Sep 2027 | Trial primary completion date: Feb 2026 --> Jul 2026
    Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    1year
    A Study to Learn About the Study Medicine Called PF-07220060 in Combination With Fulvestrant in People With HR-positive, HER2-negative Advanced or Metastatic Breast Cancer Who Progressed After a Prior Line of Treatment (clinicaltrials.gov)
    P3, N=510, Not yet recruiting, Pfizer
    New P3 trial • Combination therapy • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • PGR (Progesterone receptor)
    |
    HER-2 negative
    |
    everolimus • fulvestrant • exemestane • atirmociclib (PF-07220060)
    1year
    A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1b/2, N=240, Recruiting, Pfizer | N=144 --> 240
    Enrollment change • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    over1year
    A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1b/2, N=144, Recruiting, Pfizer | Trial completion date: Jul 2027 --> Sep 2026
    Trial completion date • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    over1year
    A Study to Learn About the Study Medicine (Called PF-07220060 in Combination With PF-07104091) In Participants With Breast Cancer and Solid Tumors (clinicaltrials.gov)
    P1b/2, N=144, Recruiting, Pfizer | Trial completion date: Dec 2027 --> Jul 2027 | Trial primary completion date: Dec 2026 --> Jul 2026
    Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    over1year
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=337, Recruiting, Pfizer | N=198 --> 337
    Enrollment change • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    over1year
    First-in-human first-in-class phase 1/2a study of the next generation CDK4-selective inhibitor PF-07220060 in patients (pts) with advanced solid tumors, enriched for HR+ HER2- mBC who progressed on prior CDK4/6 inhibitors and endocrine therapy. (ASCO 2023)
    At data cut off (Nov 1, 2022), 34 pts with advanced solid tumors received PF-07220060 in monotherapy dose escalation (Part 1A: 100–500 mg BID), and 26 pts with HR+/HER2- mBC in combination (300mg/400mg BID) with letrozole or fulvestrant (Parts 1B + 1C). PF-07220060 + ET showed efficacy in pts with HR+/HER2- mBC who progressed on prior CDK4/6i+ET. Tolerability of PF-07220060 alone and in combination with ET was encouraging. Dose expansions with PF-07220060 + ET in pts with HR+/HER2- mBC post CDK4/6i and in CDK4/6i naïve pts are ongoing.
    Clinical • P1/2 data • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2)
    |
    HER-2 negative
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)
    over1year
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=198, Recruiting, Pfizer | N=337 --> 198
    Enrollment change • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    over1year
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1/2, N=337, Recruiting, Pfizer | Phase classification: P1 --> P1/2 | N=118 --> 337 | Trial completion date: Apr 2025 --> Feb 2026 | Trial primary completion date: Apr 2025 --> Feb 2026
    Phase classification • Enrollment change • Trial completion date • Trial primary completion date • Combination therapy • Metastases
    |
    CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    Xtandi (enzalutamide capsule) • fulvestrant • letrozole • atirmociclib (PF-07220060) • midazolam hydrochloride
    over1year
    KAT6: Study of PF-07248144 in Advanced or Metastatic Solid Tumors (clinicaltrials.gov)
    P1, N=186, Recruiting, Pfizer | Trial completion date: Sep 2027 --> Nov 2026 | Trial primary completion date: Apr 2026 --> May 2025
    Trial completion date • Trial primary completion date • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • CDKN2A (Cyclin Dependent Kinase Inhibitor 2A)
    |
    ER positive • HER-2 negative
    |
    Ibrance (palbociclib) • fulvestrant • letrozole • PF-07248144 • atirmociclib (PF-07220060)
    over1year
    KAT6: Study of PF-07248144 in Advanced or Metastatic Solid Tumors (clinicaltrials.gov)
    P1, N=200, Recruiting, Pfizer | N=108 --> 200
    Enrollment change • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • CDKN2A (Cyclin Dependent Kinase Inhibitor 2A)
    |
    ER positive • HER-2 negative
    |
    Ibrance (palbociclib) • fulvestrant • letrozole • PF-07248144 • atirmociclib (PF-07220060)
    almost2years
    A Phase 1b/2 Study of PF-07220060 in Combination with PF-07104091 Plus Endocrine Therapy in Participants with BC and other Advanced Solid Tumors (clinicaltrialsregister.eu)
    P2, N=144, Ongoing, Pfizer Inc.
    New P2 trial • Combination therapy • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2)
    |
    HER-2 positive • HR positive • HER-2 negative • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060) • tagtociclib (PF-07104091)
    almost2years
    KAT6: Study of PF-07248144 in Advanced or Metastatic Solid Tumors (clinicaltrials.gov)
    P1, N=108, Recruiting, Pfizer | Trial completion date: Oct 2025 --> Sep 2027 | Trial primary completion date: May 2024 --> Apr 2026
    Trial completion date • Trial primary completion date • Metastases
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor) • CDKN2A (Cyclin Dependent Kinase Inhibitor 2A)
    |
    ER positive • HER-2 negative
    |
    Ibrance (palbociclib) • fulvestrant • letrozole • PF-07248144 • atirmociclib (PF-07220060)
    3years
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1, N=118, Recruiting, Pfizer | N=52 --> 118 | Trial completion date: Mar 2024 --> Apr 2025 | Trial primary completion date: Mar 2024 --> Apr 2025
    Clinical • Enrollment change • Trial completion date • Trial primary completion date • Combination therapy
    |
    CCND1 (Cyclin D1) • CD4 (CD4 Molecule)
    |
    HER-2 positive • HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification • HR positive + HER-2 negative • HR positive + HER-2 positive
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)
    almost4years
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1, N=52, Recruiting, Pfizer | Trial completion date: Sep 2024 --> May 2024 | Trial primary completion date: Sep 2024 --> May 2024
    Clinical • Trial completion date • Trial primary completion date • Combination therapy
    |
    HER-2 (Human epidermal growth factor receptor 2) • CCND1 (Cyclin D1)
    |
    HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)
    almost4years
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1, N=52, Recruiting, Pfizer | Not yet recruiting --> Recruiting
    Clinical • Enrollment open • Combination therapy
    |
    HER-2 (Human epidermal growth factor receptor 2) • CCND1 (Cyclin D1)
    |
    HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)
    4years
    Study to Test the Safety and Tolerability of PF-07220060 in Participants With Advance Solid Tumors (clinicaltrials.gov)
    P1, N=52, Not yet recruiting, Pfizer
    Clinical • New P1 trial • Combination therapy
    |
    HER-2 (Human epidermal growth factor receptor 2) • CCND1 (Cyclin D1)
    |
    HR positive • HER-2 negative • CCND1 amplification • CDK4 amplification
    |
    fulvestrant • letrozole • atirmociclib (PF-07220060)