INGELHEIM, Germany Boehringer Ingelheim has started a late-stage clinical trial of a drug for treating breast cancer, the German drug maker said Friday.

The phase 3 trial, dubbed the “LUX-Breast 1” trial, will evaluate the drug afatinib in patients with advanced breast cancer. The drug is a tablet that BI said was the first to inhibit two chemicals involved in tumor growth -- the epidermal growth factor receptor, or EGFR, and the human epidermal receptor, also known as HER2.

“We have seen positive results in our proof-of-concept studies for afatinib in breast cancer, and are glad to advance the program into pivotal phase 3,” BI corporate SVP medicine Klaus Dugi said. “We are delighted to be able to initiate this important trial together with a range of leading investigators to assess the value of afatinib for women with advanced breast cancer.”