On April 4, 2019, the US Food and Drug Administration (FDA) expanded the indication of palbociclib (Ibrance; Pfizer), a kinase inhibitor, in combination with specific endocrine therapies for men with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer. This is the first hormonal-based therapy to be approved for men.
Initially approved in 2015, palbociclib, in combination with an aromatase inhibitor, was the first hormonal-based therapy for postmenopausal women with metastatic breast cancer, or with fulvestrant in women with disease progression following hormonal therapy.
Breast cancer in men is rare, comprising less than 1% of all breast cancer cases, and it is estimated that approximately 2670 men will be diagnosed with breast cancer in 2019. In men, breast cancer is often found at a more advanced stage, when it has spread to other organs. It most often occurs in men aged 60 to 70 years, but men of any age can be diagnosed with breast cancer.
Most men with breast cancer have HR-positive tumors and may be treated with endocrine therapy or chemotherapy. Treatment with endocrine therapy slows or stops the growth of HR-sensitive tumors by blocking the production of hormones or by interfering with the effects of hormones on breast cancer cells. Currently, several FDA-approved endocrine-based therapies are available for the treatment of patients with HR-positive metastatic breast cancer. Under current clinical practice standards, men and women with breast cancer are treated similarly, and although gender-neutral therapies exist, these treatments are often prescribed for men, despite their gender-specific indications.
“If there is a concern that there may be a difference in efficacy or safety results between men and women, then further data may be necessary to support a labeling indication for male patients,” said Richard Pazdur, MD, Director, FDA’s Oncology Center of Excellence, and Acting Director, Office of Hematology and Oncology Products, FDA’s Center for Drug Evaluation and Research, regarding instances where a drug carries a gender-neutral indication.
The decision to expand the indication for palbociclib to include men was based on real-world data collected from postmarketing reports and electronic health records. According to Dr Pazdur, the FDA concluded on the strength of that evidence that “the safety profile for men treated with Ibrance is consistent with the safety profile in women treated with Ibrance.”
This approval follows last week’s proposal by the FDA to revamp current mammography regulations. That proposal would amend regulations issued under the Mammography Quality Standards Act of 1992 (MQSA), which Congress passed to ensure quality mammography. The MQSA authorizes FDA oversight over mammography facilities, including their accreditation, certification, annual inspections, and enforcement of standards to help ensure mammography facilities provide quality care. Mammography is an important tool in the detection of breast cancer in men as well as in women.