Talzenna (chemical name: talazoparib) was approved by the U.S. Food and Drug Administration on Oct. 16, 2018, to treat locally advanced or metastatic HER2-negative breast cancer with an inherited BRCA1 or BRCA2 mutation.
Locally advanced cancer is breast cancer that has spread to tissue near the breast, but not to parts of the body away from the breast. Metastatic breast cancer is cancer that has spread to parts of the body away from the breast, such as the bones or liver.
Talzenna is a pill taken by mouth. The recommended starting dose of Talzenna is a 1-mg tablet taken once per day, with or without food.
How Talzenna works
Most inherited cases of breast cancer are associated with two gene mutations: BRCA1 (BReast CAncer gene one) and BRCA2 (BReast CAncer gene two). Women with a mutated BRCA1 or BRCA2 gene have up to an 85% risk of developing breast cancer by age 70. Their risk of ovarian cancer also is higher than average. Men with a BRCA gene mutation have a higher risk of both breast and prostate cancer.
DNA carries genetic information in both healthy cells and cancer cells. Cells can develop DNA damage spontaneously or from exposure to specific things in the environment (too much sun, for example) that make DNA damage more likely to happen. But cells can detect and repair damage to DNA. When DNA is damaged in a healthy cell and the damage isn’t fixed, that cell can become cancerous. The function of the BRCA genes is to keep breast cells growing normally and prevent any cancer growth. But if there is a mutation in the BRCA1 or BRCA2 gene, it increases the risk of breast and other cancers because these gene mutations interfere with cells’ ability to repair damaged DNA.
The poly ADP-ribose polymerase (PARP) enzyme fixes DNA damage in both healthy and cancer cells. Research has shown that a medicine like Talzenna (chemical name: talazoparib), which interferes with (inhibits) the PARP enzyme, makes it even harder for cancer cells with a BRCA1 or BRCA2 mutation to fix DNA damage. This makes it harder for the cancer cells to survive. In other words, a PARP inhibitor makes some cancer cells less likely to survive their DNA damage.
Is Talzenna right for you?
Talzenna is used to treat locally advanced or metastatic HER2-negative breast cancer with an inherited BRCA1 or BRCA2 mutation. In order to be treated with Talzenna, you must have genetic testing that shows you have a BRCA1 or BRCA2 mutation. Genetic testing involves giving a blood or saliva sample that is analyzed to identify genetic mutations.
You are substantially more likely to have a BRCA1 or BRCA2 mutation if:
You have blood relatives (grandmothers, mother, sisters, aunts) on either your mother's or father's side of the family who had breast cancer diagnosed before age 50.
There is both breast and ovarian cancer on the same side of the family or in a single individual.
You have a relative(s) with triple-negative breast cancer.
There are other cancers in your family in addition to breast, such as prostate, melanoma, pancreatic, stomach, uterine, thyroid, colon, and/or sarcoma.
Women in your family have had cancer in both breasts.
You are of Ashkenazi Jewish (Eastern European) heritage.
You are Black and have been diagnosed with breast cancer at age 35 or younger.
A man in your family has had breast cancer.
There is a known abnormal breast cancer gene in your family.
If you have been diagnosed with locally advanced or metastatic HER2-negative breast cancer and have not had genetic testing, it’s a good idea to ask your doctor about it to see if Talzenna or another PARP inhibitor would make sense for your unique situation.
For more information on genetic testing, including types of genetic tests and costs, visit the Breastcancer.org Genetic Testing pages.
What to expect when taking Talzenna
There are certain medicines you should not take if you are taking Talzenna.
You should not take a type of medicine called a P-gp inhibitor because it increases the effects of Talzenna. This class of medicines includes Nexterone and Pacerone (chemical name: amiodarone), Coreg (chemical name: carvedilol), the antibiotic clarithromycin, Sporanox and Onmel (chemical name: itraconazole), and Verelan and Calan (chemical name: verapamil).
You also should not take a type of medicine called a BCRP inhibitor because it increases the effects of Talzenna. This class of medicines includes Zegerid and Prilosec (chemical name: omeprazole) and the antibiotic novobiocin.
It’s important to know that women who are pregnant or planning to get pregnant should not take Talzenna. Talzenna can harm the developing fetus. It’s also important that you don’t get pregnant while taking Talzenna; if there is any chance you can become pregnant, you must use effective birth control while you’re taking Talzenna and for at least 7 months after your last dose.
Also, women who are breastfeeding or plan to breastfeed shouldn’t take Talzenna. Together, you and your doctor will decide if you should take Talzenna or breastfeed.
Visit Treatment for Breast Cancer During Pregnancy for more information.
Paying for Talzenna
If your doctor prescribes Talzenna and you have problems getting it covered by insurance or have problems paying for treatment, Pfizer, the company that makes Talzenna, may be able to help. Visit Pfizer Oncology Together or call 1-877-744-5675, Monday through Friday, 8 a.m.-8 p.m. ET for more information.
Talzenna side effects
The most common side effects of Talzenna are:
thrombocytopenia (low platelet counts)
Talzenna also may cause serious side effects, including:
myelodysplastic syndrome, a bone marrow failure disorder, which means your body can no longer make enough healthy blood cells
acute myeloid leukemia, a type of blood cancer
While low red and white blood cell counts are common side effects of Talzenna, they also can be symptoms of myelodysplastic syndrome or acute myeloid leukemia. Tell your doctor right away if you have:
blood in your urine or stool
shortness of breath
bruising or bleeding more easily
Your doctor will do blood tests to check your blood cell counts every month while you are being treated with Talzenna or even weekly if you have low blood cell counts that last a long time.
Talzenna (talazoparib) prescribing information. Pfizer. New York, NY. 2018. Available at: https://labeling.pfizer.com/ShowLabeling.aspx?id=11046.
— Last updated on April 7, 2022, 1:32 PM