Cautious optimism for new breast cancer drug

An experimental inhibitor of cyclin-dependent kinases (CDK) 4 and 6 halves time to disease progression in women with hormone receptor positive metastatic breast cancer, researchers say.

Their phase 2 trial involved 165 women with advanced ER positive, HER2 negative breast cancer randomised to either letrozole plus CDK4/6 inhibitor palbociclib or to letrozole only.

Presented yesterday at the annual meeting of the American Association for Cancer Research, the results showed those on palbociclib had a median time to disease progression of 20.2 months compared with 10.2 months with letrozole only.