AstraZeneca Breast-Cancer Drug Shown to Slow Tumor Progression

A new study of an AstraZeneca PLC breast-cancer drug showed it cut the risk of tumor progression by half for people with the most advanced form of the disease, offering the prospect of a new treatment for one of the most widely diagnosed cancers.

AstraZeneca and Japan’s Daiichi Sankyo Co. said Enhertu, which the drugmakers developed jointly, stopped disease progression in patients who took it in the study for an average of 9.9 months, compared with 5.1 months for those who were given chemotherapy. The drug also cut the risk of death by 36% compared with chemotherapy. The large, late-stage trial involved 557 patients with advanced metastatic breast cancer, meaning the tumors had spread to other organs.