Should You Seek Trodelvy As A Treatment Option?
- Based on recent trials, a new drug is showing promise for metastatic breast cancer patients.
- Trodelvy (drug name sacituzumab govitecan) is an antibody-drug conjugate immune targeted therapy.
- Trodelvy may extend by 3.2 months the survival of patients with advanced stages of a common type of breast cancer, reducing the risk of death by 21%.
- HER2 is a gene that can play a role in the development of breast cancer.
- It’s important to note that the study focused on HER2 negative patients.
Updated results from a trial show the phase III TROPiCS-02 study presented at the European Society for Medical Oncology (ESMO) Congress 2022 showed that Gilead’s drug, Trodelvy, demonstrated exciting results for breast cancer patients who had hormone-sensitive tumors that tested negative for a receptor called HER2 and who had stopped responding to at least two earlier courses of therapy.Read More
What is HER2 Breast Cancer?
It’s important to note that this study focused on HER2 negative patients. But what is that? HER2 stands for human epidermal growth factor receptor 2. It’s a protein that helps breast cancer cells grow quickly.
Traditionally, the presence of HER2 has been divided into two groups, either positive or negative, leaving about 50 percent of patients somewhere in the middle. These groupings are based upon the way the tumors appear under a microscope when graded by the pathologist or with additional testing a pathologist may perform.
Patients with HER2 positive tumors have tumors that show HER2 over-expression while patients with HER2 negative tumors show minimal or no expression.
Recently, however, researchers have looked to expand this definition further to include patients that have a minimal amount of HER2 expression but do not meet the classic definition for HER2-positive tumors. This group has been called HER2 "low" and is very important as it represents approximately 50 percent of all patients with breast cancer.
Metastatic Breast Cancer
Breast cancer is such a common cancer that many women have been touched by it in some way– either they've been diagnosed themselves, or they know someone who has been diagnosed.
Stage four breast cancer means that your cancer has now spread to distant areas of the body. It is no longer regionalized to the breast. And while there is no cure for metastatic breast cancer, doctors have a lot of options to treat this stage of advanced disease. One advantage to being such a common cancer is that breast cancer has been the focus of much research. What scientists have learned in the lab have translated into new and breakthrough treatments that are dramatically improving the outlook for people with this cancer. So if you have been diagnosed, you can be sure that your doctor will have a lot of options for treating you.
How Does Trodelvy Work?
In the words of Dr. Oratz: “So, in this case, we’re using an antibody that is directed to go straight to the cancer cell and then drop into it a little tiny amount of a drug that’s going to be very toxic to the cancer cell but not so toxic overall to the patient, as opposed to old fashioned chemotherapy which went everywhere in the body. It wasn’t targeted. It wasn’t specific.”
Trodelvy is a type of drug called an antibody drug conjugate. That means it's an antibody and drug combined. The way it works is that the anti-cancer drug is attached to an antibody that recognizes cancer cells. When the drug enters the blood stream, by IV infusion, the antibodies deliver the anti-cancer drug directly to the cancer cells. Because the drug goes straight to cancer cells, it has minimal effects on healthy cells.
Traditional chemotherapy, on the other hand, doesn't target cancer cells as strictly. It can damage healthy cells, too. That's what causes the side effects for which chemo is well known.
That doesn't mean that Trodelvy is without side effects. About one in ten people who take the drug have severe diarrhea. About half hit very low levels of the type of white blood cell (neutrophils) that help fight bacterial infections.
What’s the Data?
The trial was a global, multi centric, phase III, randomized study. It evaluated Trodelvy versus physicians' choice of chemotherapy in 543 patients with HR+/HER2- metastatic breast cancer who were previously treated with endocrine therapy, CDK4/6 inhibitors and two to four lines of chemotherapy for metastatic disease.
Follow-up was conducted at a median of 12.5 months.
Trodelvy demonstrated statistically significant and clinically meaningful improvements in overall survival (OS) compared to treatment of physician's choice in pretreated patients with hormone receptor (HR)-positive/HER2-negative metastatic breast cancer who are resistant to endocrine therapy. OS is defined as the time from treatment to death, regardless of disease recurrence.
The results demonstrated a median OS of 14.4 months with Trodelvy compared with 11.2 months with treatment of physician's choice. This represents a 3.2-month improvement in survival and a 21% relative reduction in the risk for death.
According to Sarah P. Cate, Director of the Breast Surgery Quality Program at Mount Sinai Health System, even small changes in survival for metastatic breast cancer are important. Hormone positive, HER2 negative breast cancers comprise the majority of cancers diagnosed every year. About 30% of early stage hormone positive, HER2 negative breast cancers metastasize after 10 years. So any advancement in survival in this group is important.
“Trodlevy is another therapy for us to utilize in this group. Further studies will be needed to ascertain if it will be utilized as a frontline agent,” Dr. Cate tells SurvivorNet.
Safety results for Trodelvy were consistent with prior results, and no new safety signals were observed.
Possible Side Effects
The most common side effects from Trodelvy include:
- Nausea and vomiting
- Diarrhea or constipation
- Hair Loss
- Appetite loss
- Abdominal pain
This drug carries a boxed warning about the risk of more serious side effects, such as low white blood cell counts and severe diarrhea. White blood cells are the immune system's infection fighters, and a drop in these cells could increase your risk of getting sick. If you take this drug, your doctor has treatments to boost your white blood cell count and to relieve diarrhea. Your doctor should carefully monitor you for side effects while you take Trodelvy, and lower the dose or stop the drug entirely if your side effects are serious.
Questions to Ask Your Doctor
- Should I be tested for HER2 mutation?
- Am I eligible to receive Trodelvy?
- How will I feel during treatment?
- What are the most common side effects of Trodelvy?
- What will my treatment cost? Will my treatment be covered by my medical insurance company?