On 4 April 2019, the US FDA approved palbociclib (Ibrance®, Pfizer) plus aromatase inhibitor or fulvestrant for the treatment of male patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer.

Post-marketing Data and Electronic Health Records

The FDA approval is based on real-world efficacy and safety data from post-marketing reports and electronic health records using palbociclib in male patients which showed consistency with the the data of palbociclib in women.

Male breast cancer is an uncommon malignancy and makes up less than 1% of all breast cancer cases. Most male breast cancer patients are diagnosed at a later age, with more advanced stage disease, and the vast majority of male breast cancers are HR-positive. The treatment is similar to the treatment of female breast cancer, although not all therapies are approved for use in male patients.  

Safety

Common side-effects of palbociclib are infections, leukopaenia, fatigue, nausea, stomatitis, anaemia, hair loss, diarrhoea, thrombocytopenia, rash, vomiting, decreased appetite, asthenia and fever. There is a potential for genotoxicity and healthcare providers are advised to inform male patients and their female partners of child-bearing potential to use effective contraception during treatment with palbociclib up to three months after the last dose. Pregnant and breastfeeding women are advised not to take palbociclib.

Full prescribing information Ibrance®