Oct 6 (Reuters) - AstraZeneca ( AZN ) and Daiichi

Sankyo's ( DSKYF ) precision drug Datroway improved survival

prospects in patients with an advanced form of breast cancer in

a late-stage trial, the drugmakers said on Monday, paving the

way for broader approvals.

The trial was for patients with a type of aggressive and

advanced breast cancer for whom immunotherapy was not an option,

AstraZeneca ( AZN ) said. The treatment was given early and compared

with chemotherapy.

The company added that Datroway was the first therapy to

significantly improve overall survival in this group, and that

it also significantly improved progression-free survival and met

the dual main goal of the study.

"We expect today's results will mark an inflection point in

the treatment of these patients who have the poorest prognosis

of any type of breast cancer and urgently need better options,"

said Susan Galbraith, AstraZeneca's ( AZN ) executive vice president,

Oncology Haematology R&D.

Datroway belongs to a class of medicines called

antibody-drug conjugates, also known as "guided-missiles"

because they are designed to target only cancer cells while

sparing healthy cells, unlike conventional chemotherapy.

It works by targeting the TROP2 protein found on the surface

of tumour cells of many types of cancer, and is already approved

for treating a form of breast cancer and a type of lung cancer.

AstraZeneca ( AZN ), whose shares rose nearly 1% in early trading,

said the companies would share detailed results of the latest

trial with regulators and present them at an upcoming,

unspecified medical conference.

(Reporting by Pushkala Aripaka in Bengaluru; Editing by

Nivedita Bhattacharjee and Mrigank Dhaniwala)