(Sharecast News) - AstraZeneca and Daiichi Sankyo's Enhertu cancer drug has been approved in the US for adult patients with unresectable or metastatic solid tumours who have received prior systemic treatment and have no satisfactory alternative options.

The decision was based on successful phase two trials which showed "clinically meaningful responses across a broad range of tumours", the two companies said on Monday.

"Until the approval... patients with metastatic HER2-positive solid tumours have had limited treatment options. Based on the clinically meaningful response rates seen across clinical trials, this tumour-agnostic approval means that patients may now be treated with a HER2-directed medicine," said Funda Meric-Bernstam, chair of investigational cancer therapeutics at The University of Texas MD Anderson Cancer Center.

HER2-directed therapies have been used to treat breast, gastric, lung and colorectal cancers for a number of years. Although HER2 is expressed in solid tumour types including biliary tract, bladder, cervical, endometrial, ovarian and pancreatic cancers, testing is not routinely performed in these additional tumour types and as a result, available literature is limited.

Reporting by Frank Prenesti for Sharecast.com