A new cancer drug called trastuzumab deruxtecan, also known as Enhertu, has just been approved in the UK . This drug is designed to help adults with certain types of advanced cancer that cannot be removed by surgery, or which has spread to other parts of the body.
Author
- Justin Stebbing
Professor of Biomedical Sciences, Anglia Ruskin University
It targets cancers linked to a protein called HER2. This approval is an exciting development because it could save lives and offer hope to patients who may have run out of treatment options.
The drug has been authorised for use in the UK on the back of positive data, where patients were randomly assigned to this drug or the previous existing best treatment, which I have led studies on with large teams of researchers.
Using this new precision medicine or targeted therapy, those who received the drug, had longer lives (as measured by these clinical trials ). Other research I have been involved with has shown, that this is what matters most for the patients themselves , though, of course, quality of life is a priority too.
Cancer is one of the biggest health challenges we face today . While there are many treatments available, not all cancers respond well to them. Some cancers grow and spread very quickly, making them harder to control . Others stop responding to treatments that initially worked, leaving patients with few options. For people with these types of cancers, new drugs can make a huge difference. They can help patients live longer, improve their quality of life, and provide hope when other treatments fail.
Targeted treatment
One reason new drugs are so important is that they often offer better ways to treat cancer. Older treatments like chemotherapy can be effective but often harm healthy cells along with cancer cells, causing unpleasant side effects. Newer drugs are more targeted, meaning they focus on killing cancer cells while leaving healthy cells alone as much as possible. This makes treatment less harsh and more effective. Drugs like Enhertu represent this new generation of targeted therapies, though it can have very serious side effects.
To understand how it works, it's helpful to know about HER2. HER2 is a protein found on the surface of some cells in the body. It helps cells grow and divide normally, but in certain cancers, there's too much HER2 . This overproduction causes the cancer to grow faster and become much more aggressive. These types of cancers are called HER2-positive cancers, and they can occur in places like the breast, stomach and lungs.
Enhertu is part of a newer type of cancer treatment called antibody-drug conjugates (ADC). It works like a delivery system for medicine, even a "biologic missile" . Imagine you're trying to deliver a package (a powerful cancer-killing drug) directly to a specific house (the cancer cell). You don't want the package to end up at the wrong house (healthy cells), because it could cause damage there. An ADC uses an antibody, a special protein that acts like a guide, to make sure the package is delivered to the correct address .
Trojan horse
First, the antibody part of the drug finds and attaches itself to HER2 on the surface of cancer cells. Once attached, the drug gets pulled inside the cancer cell like a Trojan horse. Inside the cell, it releases its chemotherapy agent, a strong medicine that kills cells and destroys the cancer from within.
The drug can also kill nearby cancer cells that might not have as much HER2 but are still part of the tumour. This precise targeting means fewer healthy cells are harmed during treatment .
The approval of Enhertu in the UK is great news for patients with advanced HER2-positive cancers that have spread or cannot be removed by surgery. Up to 20% of breast cancers are HER2 positive and many of these are cured before they spread. What's even more exciting is that this drug also works for people with lower levels of HER2 (called HER2-low cancers), which means it could help even more patients in the future.
For patients with advanced or hard-to-treat cancers, this approval offers new hope. Many people with HER2-positive cancers have already tried treatments like chemotherapy or surgery. Most of those will have had other anti-HER2 drugs but will still need help because their cancer has come back or spread further. This drug has shown in clinical trials that it can shrink tumours and help patients live longer than standard treatments. It gives doctors another option when other treatments aren't working anymore .
This approval also highlights how international collaboration can speed up access to life-saving drugs. The investigators here worked collaboratively across numerous countries in the world to undertake these studies.
But while Enhertu brings hope to many patients, it's important to remember that no drug is perfect. Like all medicines, it comes with some risks and side effects. Common side effects include nausea, fatigue and low blood counts. A rare but serious side effect is interstitial lung disease, which affects the lungs and can be dangerous if not treated quickly. Doctors will carefully monitor patients taking this drug to catch any problems early and stop the drug if necessary.
Despite these risks, in most situations doctors and patients feel that the potential benefits outweigh them. It offers a chance for better outcomes, in those for whom it is suitable.
This approval also represents progress in how we treat cancer using personalised medicine (an approach where treatments are tailored specifically for each patient based on their unique biology or the genetic makeup of the cancer) to treat the right person at the right time with the right drug.
Every breakthrough like this brings us closer to a world where fewer people die from cancer, and where those who do face it have better chances of living longer and healthier lives.
Justin Stebbing does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
