Oct 6 (Reuters) - AstraZeneca ( AZN ) said on Monday its

precision drug Datroway improved overall survival and

progression free survival in patients with an advanced form of

breast cancer versus chemotherapy in a trial when given early

during treatment.

The treatment, which is being developed with partner Daiichi

Sankyo ( DSKYF ), was given as first-line therapy in the trial

for patients with metastatic triple-negative breast cancer for

whom immunotherapy was not an option, AstraZeneca ( AZN ) said.