AstraZeneca’s Faslodex has been cleared on both sides of the Atlantic for use in combination with a CDK4/6 inhibitor.

In the EU, the drug’s use has been approved for use alongside the CDK4/6 inhibitor palbociclib to treat a certain form of breast cancer, in the US it can be prescribed in combination with the CDK4/6 inhibitor abemaciclib.

Both the European Commission and US Food and Drug Administration have approved the combination for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) locally advanced or metastatic breast cancer in women who have received prior endocrine therapy.

“For many years fulvestrant has been used as an effective monotherapy treatment for women with hormone receptor positive breast cancer,” said said David Fredrickson, head of the Oncology Business Unit at AZ. The drug’s approvals in combination with a CDK4/6 inhibitor “reinforces the value of fulvestrant as an endocrine agent of choice for advanced breast cancer patients”.

EU approval is based on data from the Phase III PALOMA-3 trial, which showed a statistically significant increase in investigator-assessed median progression-free (PFS) survival of 4.9 months (9.5 months versus 4.6 months) in patients who received Faslodex 500mg and palbociclib 125mg over Faslodex and placebo.

US clearance rides on the back of data from the Phase III MONARCH 2 trial, which showed a statistically significant increase in investigator-assessed median PFS of 7.1 months (16.4 months vs 9.3 months) in patients who received Faslodex 500mg and abemaciclib 150mg over those receiving a Faslodex/placebo combination.

AZ’ drug is currently approved in over 80 countries as a monotherapy to treat ER+ advanced breast cancer patients, and is also being evaluated in combination with medicines from various drug classes for the treatment of women with HR+ advanced breast cancer.