What is Pembrolizumab, cancer drug that doubles the survival rate? – Firstpost

Hundreds of thousands of patients with advanced head and neck cancer could live years longer without the disease, thanks to a breakthrough immunotherapy drug, a new clinical trial suggests.

The study revealed that the drug called pembrolizumab, sold under the brand name Keytruda, kept head and neck cancers at bay for five years compared to 30 months with standard care.

When added to current therapies, it could potentially double the time patients live without a recurrence, making it one of the biggest breakthroughs in two decades.

Kevin Harrington, professor of biological cancer therapies at the Institute of Cancer Research in London and lead researcher of the trial, described the development as game-changing.

“This could change the world for these patients,” he told the BBC. “It significantly decreases the chance of cancer spreading around the body, at which point it’s incredibly difficult to treat.”

So, how exactly does Pembrolizumab work? And what did the trial reveal? We break it down.

‘A gift of life’

For Laura Marston, a 45-year-old from Derbyshire, the immunotherapy drug pembrolizumab has been nothing short of “a gift of life”.

Back in 2019, Laura noticed an ulcer on her tongue that just wouldn’t heal. Tests revealed it was cancer, and doctors gave her only a 30 per cent chance of long-term survival.

“I was 39 and I was devastated,” she told the BBC.

The road ahead was tough. She had to undergo major surgery to remove her tongue and the lymph nodes in her neck. After that came the even harder part, learning how to talk and eat again.

“My prognosis was quite dire,” she recalled. Surgeons had to use muscle from her left arm to rebuild the inside of her mouth. It changed her life in every way.

But amid the struggle, there was hope.

Laura joined an international clinical trial testing a new approach to treatment, one that used pembrolizumab not just after surgery, but also before it.

The clinical trial, led by researchers at Washington University School of Medicine and involving scientists from the Institute of Cancer Research in London, enrolled over 700 patients across 24 countries.

The trial, which is being presented at the American Society of Clinical Oncology (Asco), the world’s largest cancer conference, showed that the patients who received pembrolizumab lived cancer-free for twice as long, five years on average, compared to just 2.5 years with standard treatment.

The drug also cut the chances of the cancer returning elsewhere in the body by 10 per cent after three years.

“Immunotherapy has been amazingly beneficial for patients whose cancer has come back or spread,” said Harrington, who co-led the study, told The Guardian. “But until now, it hadn’t shown this kind of success in people being treated for the first time.”

Today, six years after her diagnosis, Laura is working full-time and doing well.

“It’s been phenomenal for me,” she said. “Because I’m here, able to talk to you. Just having this amazing immunotherapy has given me my life back again.”

How does the drug work?

Unlike traditional cancer treatments like chemotherapy, which attack the tumour directly, immunotherapy works by boosting the body’s own defences. It helps the immune system recognise cancer cells and destroy them.

In this trial, researchers found that the timing of the drug was key. Patients were given pembrolizumab before surgery, allowing their immune systems to get familiar and kill the cancer if it ever comes back.

“We give the immune system the chance to have a good look at the tumour to generate anti-tumour immunity,” explained Harrington told BBC. “Then, after removal of the tumour, we continue to amplify that immune response by giving the drug continually for up to a year.”

The treatment worked especially well for people with high levels of a protein called PD-L1, which acts as a marker for how active the immune system might be. But even patients without high PD-L1 levels saw clear benefits. The risk of cancer returning or spreading dropped significantly across the board.

“This research shows that immunotherapy could change the world for these patients,” Harrington said. “It significantly decreases the chance of cancer spreading around the body, and that’s when it becomes incredibly difficult to treat.”

With input from agencies