Intismeran Vaccine Stops Melanoma Returning

A new personalised vaccine has stopped melanoma from returning in patients during a major clinical trial. The vaccine, called Intismeran and developed by drug companies Merck & Co (MSD) and Moderna, was given in combination with the immunotherapy drug Keytruda to patients after surgery for high-risk skin cancer. For more on how treatments are tested, see our fixtures page.

Early results announced by the two firms show the combination significantly increased the length of time patients remained cancer-free compared to taking Keytruda alone. The treatment also reduced the risk of the disease spreading to other organs. The full results have not yet been released or peer-reviewed.

How The Personalised Vaccine Works

The companies are calling Intismeran a personalised cancer vaccine. To create it, scientists surgically remove a small part of a patient's tumour and sequence its DNA. They then use mRNA technology, the same platform used for some Covid-19 vaccines, to target specific mutations found in that individual's cancer cells.

The resulting jab instructs the patient's immune system to recognise and attack any remaining tumour cells. Professor Peter Johnson, National Clinical Director for Cancer at NHS England, told the BBC this represents an important shift. He said most of the cancer immune treatments used up until now have been about cutting the immune system loose and hoping that it recognises the cancer, and that this new treatment is a way to direct it very specifically.

Trial Details And Expert Caution

The phase three trial involved more than 1,000 patients with high-risk stage two, three, or four melanoma. This means participants ranged from having large tumours in a specific area to cancers which had already spread to other parts of the body. You can explore detailed stats on cancer outcomes.

While experts have hailed the news as a breakthrough, they emphasise caution. Dr Talisia Quallo, head of prevention and early detection at Cancer Research UK, said the research shows promise but noted the interim data still needs to be fully reviewed. She added that it is vital that research like this continues to be funded so that more people with cancer can have personalised treatment options.

Dr Lennard Lee, a consultant medical oncologist at the University of Oxford, said the study provides proof that personalised cancer vaccines work. He believes the implications extend far beyond melanoma.

The Road Ahead For Patients

Even after the trial process concludes, the treatment would need approval from regulators like the UK's Medicines and Healthcare products Regulatory Agency. It would then go through a separate assessment before potentially being made available on the NHS. Professor Johnson said the NHS is preparing to bring this type of treatment to patients.

The two companies are already testing similar personalised mRNA vaccines for other cancers, including lung, bladder, and kidney cancers. More detailed findings from the melanoma study will be presented at a medical conference in October. Shares in both Moderna and Merck surged following the announcement.