UPDATE 1-AstraZeneca-Daiichi's breast cancer drug improves survival in study

(Adds detail on study, executive comment, background on drug)

Aug 15 (Reuters) - AstraZeneca said on Monday its cancer drug, Enhertu, developed with Japan's Daiichi Sankyo delayed the progression of a form of advanced breast cancer in previously treated patients, boosting prospects of more regulatory approvals.

Enhertu met the main goal of a late-stage study testing the drug against a treatment pre-determined by physicians in people with HER2-positive metastatic breast cancer, the company said. The HER2 protein contributes to the growth and spread of breast cancer.

In the trial, DESTINY-Breast02, Enhertu showed a statistically significant and clinically meaningful improvement in progression-free survival, a measure of how long a person can live without the disease worsening.

"As this is the confirmatory trial for our current breast cancer indication in Europe and several other countries, we look forward to sharing these findings with regulatory authorities," said Ken Takeshita, global head for R&D at Daiichi Sankyo.

Earlier this month, AstraZeneca and Daiichi secured U.S. approval for a wider use of the drug in patients with breast cancer, paving the way for billions in sales. (https://reut.rs/3QrLwqP)

The drug, which generated sales of $214 million in 2021, belongs to a class of therapies called antibody drug conjugates. It comprises a monoclonal antibody chemically linked to a cell-killing chemotherapy drug. (Reporting by Pushkala Aripaka in Bengaluru; Editing by Vinay Dwivedi)