Ibrance (palbociclib), developed by Pfizer, is the world's first CDK4/6 inhibitor to be marketed globally. It was first approved in February 2015 and is currently approved in over 90 countries worldwide for first- and second-line treatment of HR+/HER2- breast cancer. Recently, there has been more good news: the US FDA has approved a supplemental New Drug Application (sNDA) for Ibrance, expanding its indications for combination therapy with aromatase inhibitors or fulvestrant to include male patients with hormone receptor-positive (HR+), epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer.
Ibrance Approved for First- and Second-Line Treatment of Male Breast Cancer_Hong Kong Jiming Pharmaceutical
Notably, this approval makes Ibrance the world's first and only CDK4/6 inhibitor approved for first-line treatment of HR+/HER2- metastatic breast cancer in men, in combination with an aromatase inhibitor. Ibrance is now available for adult patients with HR+/HER2- advanced or metastatic breast cancer, including in combination with an aromatase inhibitor as initial endocrine therapy for postmenopausal women or men; and in combination with fulvestrant for patients whose disease has progressed after endocrine therapy.
While male breast cancer is relatively rare and clinical trials involving male patients are limited, it is projected that there will be 2,670 new cases of invasive breast cancer in men and 500 deaths from metastatic breast cancer in the United States in 2019. Treatment options for male breast cancer patients are very limited, but this approval of Ibrance will bring Ibrance to the underserved male breast cancer community and provide more patients with HR+, HER2- metastatic breast cancer with access to innovative treatments.
This approval of Ibrance for male breast cancer is based on data from electronic health records and post-marketing reports of male patients treated with Ibrance in the real world, sourced from three major databases: the IQVIA Insurance Database, the Flatiron Health Breast Cancer Database, and the Pfizer Global Safety Database.
Ibrance, a first-in-class oral targeted CDK4/6 inhibitor, primarily works by selectively inhibiting cyclin-dependent kinases 4 and 6 (CDK4/6), restoring cell cycle control and blocking tumor cell proliferation. Uncontrolled cell cycle is a hallmark of cancer, and CDK4/6 is overactive in many cancers, leading to uncontrolled cell proliferation. CDK4/6 are key regulators of the cell cycle, triggering the transition from the growth phase (G1 phase) to the DNA replication phase (S1 phase). In estrogen receptor-positive (ER+) breast cancer, CDK4/6 overactivity is very frequent, and CDK4/6 is a key downstream target of ER signaling. Preclinical data indicate that dual inhibition of CDK4/6 and ER signaling has a synergistic effect and can inhibit the growth of G1 phase ER+ breast cancer cells.
