A new drug for advanced prostate cancer has shown promise in early trials experts have said, with the medication shrinking tumours in some patients.

Prostate cancer is the most common cancer among men in many countries, including the US and UK. About 1.5 million men are diagnosed worldwide each year.

The new drug has caused excitement as it is a type of treatment called immunotherapy. This approach uses the body’s own immune system to fight disease, and has already proved beneficial for some cancers. However, experts note it has not yet had the same impact on prostate cancer.