A lung cancer therapy can more than double life expectancy in some patients, a "milestone" trial shows, reports BBC.
Nivolumab stops cancerous cells hiding from the body's own defences, leaving the cancer vulnerable to attack.
The results from 582 people, presented at the American Society of Clinical Oncology, were described as "giving real hope to patients".
Lung cancer is the most deadly type of cancer, killing nearly 1.6 million people every year. It is hard to treat as it is often diagnosed late and many people with smoking-related diseases are unsuitable for surgery.
The trial, conducted in Europe and the US, was on patients who had advanced lung cancer and who had already tried other treatments. People on standard therapy lived for another 9.4 months at this stage, but those taking Nivolumab lived for 12.2 months on average.