New research hailed as ‘promising’ for thousands with advanced bowel cancer
A new drug has shown promising results in treating advanced bowel cancer in people with specific genetic changes, doubling their ‘progression free survival’ time.
The new treatment, pembrolizumab, increased the amount of time patients live with the disease without it getting worse from 8.2 months for those who were given chemotherapy to 16.5 months on average.
The results, which will be presented at the American Society of Clinical Oncology (ASCO) virtual conference, also revealed that 11% of patients treated with pembrolizumab were found to have a ‘complete response’ where their disease became completely undetectable on scans.
People with advanced bowel cancer, where the disease has spread to other parts of the body, are normally treated with chemotherapy; sometimes in combination with other treatments such as avasin or cetuximab. However, around 5% of bowel cancer patients have changes to their microsatellite instability high (MSI-H) or mismatch repair deficiency (dMMR) genes - such as people with Lynch Syndrome – which makes them less likely to respond well to these currently available treatments, often leading to poorer outcomes.
Genevieve Edwards, Chief Executive of Bowel Cancer UK, says: "These findings have the potential to be game changing for people with advanced bowel cancer with these specific genetic changes, including people with Lynch Syndrome. While we’re still some way off having pembrolizumab in routine use on the NHS, this is a promising step in the right direction.”
Pembrolizumab (also known as MK-3475), is an immunotherapy, which works by helping the immune system to recognise and attack cancer cells. This doesn’t happen naturally, as cancer begins life as normal cells within our bodies and our immune system is taught not to recognise and kill anything which belongs to us, only foreign invaders
The KEYNOTE-177 clinical trial - a large international trial involving UCL and University College London Hospitals NHS Foundation Trust - compared giving patients pembrolizumab against standard treatment for advanced bowel cancer patients with these specific genetic changes.
The interim findings also found that cancer in almost half of the patients who took pembrolizumab had not progressed after two years, compared with a fifth of patients who received chemotherapy, which means the benefits of pembrolizumab are long lasting.