Abu Dhabi hospital gives world’s first clinical dose of new breast cancer drug

A hospital in Abu Dhabi has become the first in the world to give a patient Camizestrant as part of routine clinical care. Burjeel Cancer Institute, working under the supervision of the Department of Health Abu Dhabi, administered the drug to a woman in her forties with advanced breast cancer. The move marks a real shift in how doctors can respond to treatment resistance before it becomes a bigger problem.

The patient had developed a mutation in the ESR1 gene, a change that can make standard hormone therapy stop working and allow cancer to grow. Instead of waiting for scans or symptoms to confirm the disease was getting worse, doctors caught the mutation early using a blood test that detects cancer DNA circulating in the bloodstream. That early warning gave them the window they needed to switch to a more targeted treatment.

Camizestrant is not yet widely available in clinical settings, making this case significant both for the patient and for what it signals about Abu Dhabi's push to bring advanced cancer treatments to patients faster than most health systems manage.

How does it work?

The key to this case is a technique called circulating tumour DNA monitoring, or ctDNA testing. When cancer cells die, they shed small fragments of DNA into the bloodstream. A blood test can pick up these fragments and look for specific mutations that suggest the cancer is changing or becoming resistant to treatment.

In this patient's case, the test found an ESR1 gene mutation. This mutation is known to cause resistance to standard endocrine therapy, the type of hormone-blocking treatment commonly used for certain breast cancers. Catching it in the blood before it showed up on a scan gave doctors a critical head start.

Camizestrant works differently from standard endocrine therapy. It targets the oestrogen receptor in a more precise way, and is designed specifically to work even when the ESR1 mutation is present. By switching to it early, the clinical team aimed to:

• Keep the cancer under control for longer
• Delay further progression
• Protect the patient's quality of life

Why does it matter?

The global SERENA-6 clinical trial provided the evidence behind this decision. That trial showed that patients with an ESR1 mutation who switched to Camizestrant had a 56% lower risk of disease progression or death compared to those who stayed on conventional endocrine therapy.

What makes SERENA-6 unusual is its design. It is the first large global trial to use serial ctDNA monitoring to trigger a treatment change before any visible or clinical sign of progression appears. That is a meaningful departure from the standard approach, which typically waits for scan results to confirm the cancer is growing before changing course.

Treating the molecular signal rather than waiting for visible disease gives oncologists an earlier intervention point, which could translate into better outcomes for patients with this type of mutation.

The context

Advanced breast cancer that is hormone receptor positive is one of the most common types of breast cancer diagnosed globally. For many patients, endocrine therapy works well initially, but ESR1 mutations are a well-documented reason it eventually stops working. Studies estimate that ESR1 mutations appear in roughly 30 to 40 percent of patients with hormone receptor positive, HER2 negative metastatic breast cancer who have been treated with aromatase inhibitors.

The broader trend here is precision oncology: using molecular data to make treatment decisions rather than relying solely on imaging or symptoms. Liquid biopsies, the umbrella term for blood-based tests like ctDNA monitoring, have been growing in clinical use for several years, but their role in actively guiding treatment switches in real time is still relatively new.

Abu Dhabi has positioned itself as a regional hub for this kind of advanced care, investing in diagnostic technology, clinical trial access, and specialist oncology infrastructure. Being the site of the world's first clinical administration of Camizestrant fits that pattern, and reflects a broader push by the emirate to attract and deploy medical innovations ahead of most other health systems.