Over the past 10 years, cancer treatment has been moving towards precision medicine – that is, tailoring treatments more to specific genetic or molecular features of the cancerous tissue. We have written before about how important it is to know your genetic status and make sure to ask your doctor if they have done genetic testing on the cancer tissue itself. This can help guide treatment decisions and also see if you are eligible for exciting clinical research trials. It is important that you are tested when you are initially diagnosed and if the cancer ever comes back after remission.
Earlier this year, some very exciting research was published that looked at a new drug called Trastuzumab-deruxtecan (Abbreviated ‘T-DXd,’ or Brand name ‘Enhertu’). This drug was shown to work very well in patients who have cancer tissue that shows ‘HER2’ on molecular testing. The drug works by combining two different types of medications into one – called an ‘Antibody Drug Conjugate.’
The study called the ‘Destiny’ Trial, looked at patients who had endometrial, cervical, ovarian, bladder, pancreatic, and other cancers. The cancers had to have spread outside of the original organ to nearby tissue (‘locally advanced’) or far away (‘metastatic’). Patients had to have completed one treatment already or had no treatment options available. The drug was given intravenously once every 3 weeks. Patients who had a high (2+ or 3+) level of HER2 expression were studied. The researchers’ main goal was to see how many patients had their tumors shrink.
There were a total of 267 patients in the trial, 40 of whom had endometrial cancer. In patients with endometrial cancers with very high (3+) levels of HER2, 85% of them had their tumors shrink. In patients with high (2+) levels of HER2, 47% responded. These are really amazing response rates (currently, response rates to standard therapies are generally 20% and, at best, 60%). Also importantly, the responses lasted for at least 1 year and much longer in others. The side effects of the drug included nausea, diarrhea, and fatigue. The drug can affect the lungs very seriously so patients have to be closely monitored with lung studies.
Because of the incredible research data, the Food and Drug Administration gave accelerated approval for its use in any patient with HER2+ cancer.
So – ask your doctor what your HER2 status is! If you have 2+ or 3+, see if you are eligible for this new drug! If you are HER2 zero or 1+, ask if there is a clinical trial in which you can enroll. And always ask about molecular/genetic testing.
Find more information here and here!
by Charlotte R. Gamble MD MPH – Gynecologic Oncology, Georgetown University, MedStar Health