A blood test designed to find cancer early did not work as hoped in a major new study, according to the company that makes it. The test, called Galleri, failed to lower the number of people diagnosed ...

A closely watched clinical trial in Britain that screened blood for early detection of cancer did not show a reduction in diagnoses at later stages of the disease.

Shares of early cancer-detection test maker Grail plunged 50% early Friday after a landmark U.K. study showed the test didn’t significantly reduce later-stage cancer cases. Grail said late Thursday ...