lose (one's) battle

Translations
проиграть (свою) битву
Despite his efforts, he finally lost his battle against the disease.
Несмотря на свои усилия, он в конце концов проиграл свою битву с болезнью.
Definitions
To fail in one's efforts to overcome a challenge, illness, or difficult situation, often used in the context of someone dying after a struggle with a disease or adversity.