Capivasertib Shown to Delay Disease Progression
There is good news for people living with hormone receptor (HR)-positive, HER-2 negative breast cancer that has not responded to aromatase inhibitors. A new drug called capivasertib, combined with the chemotherapy drug fulvestrant, seems to slow disease progression.1
Currently, HR positive, HER-2 negative breast cancer treatment includes two different drugs. One is an endocrine therapy called an aromatase inhibitor. It blocks the production of estrogen. The other is called a CDK4/6 inhibitor. This type of drug stops cells from making copies of themselves.1
Doctors found that after a while, cancer cells stopped responding to these drugs. Researchers have created new CDK4/6 inhibitors to use. But endocrine therapies have not been as effective. Fortunately, researchers found another process in the body (pathway) that cancer cells use.1
How does capivasertib work?
Endocrine cancers like these often have gene changes (mutations) that affect the AKT pathway. The AKT gene is important to help cells grow and replicate. When cancer cells have mutations in genes like AKT, they grow out of control. Capivasertib blocks AKT proteins to stop cell growth. This, then, stops tumors from getting larger.2
Evidence for capivasertib
The results of a clinical trial involving capivasertib were released in December 2022. In this study, researchers looked at people living with HR positive, HER-2 negative breast cancer that were no longer responding to aromatase inhibitors. One group received capivasertib along with fulvestrant. The other group received fulvestrant and an inactive substance (placebo).1
This and other studies showed that capivasertib increased progression-free survival (PFS) in this population. The people who were given both fulvestrant and capivasertib had an average PFS of 10.3 months. In comparison, those who took fulvestrant and the placebo had an average PFS of 4.8 months.3
Capivasertib also affected overall survival time. Those who took fulvestrant and the placebo lived 23.4 months after they began treatment. Those who took both capivasertib and fulvestrant lived 29.3 month after the start of treatment.3
What are the possible side effects of capivasertib?
Like all drugs, capivasertib has side effects. Over half of the people in the study reported diarrhea as a side effect. Other common side effects were nausea, rash, fatigue, and high blood sugar. A small number of people also experienced high blood pressure as a side effect.2,3
What does this mean for future treatment?
Capivasertib is an important discovery because it is the first drug in the AKT inhibitor class. Studies have shown that it can extend overall cancer survival time and increase how long you can live without cancer progression. This is exciting because capivasertib may help you live longer while preserving your quality of life. This time can be spent doing the things you love with the people you love.1
This discovery also opens the door to more research. Understanding how capivasertib slows down cancer growth can help experts understand what causes these cancers. Researchers can now work to improve the drug and create more effective drugs in its class.1
If you are living with HR positive, HER-2 negative breast cancer and would like to learn more about capivasertib, talk to your doctor.
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