On Jan. 12, 2018, the U.S. Food and Drug Administration approved Lynparza (chemical name: olaparib) to treat metastatic, HER2-negative breast cancer in women with an inherited BRCA1 or BRCA2 mutation that has been previously treated with chemotherapy.
Most inherited cases of breast cancer are associated with mutations in genes: BRCA1 (BReast CAncer gene one) and BRCA2 (BReast CAncer gene two). Women with a mutation in the BRCA1 or BRCA2 gene have up to a 72% risk of developing breast cancer by age 80. Their risk of ovarian cancer also is higher than average. Men with an abnormal BRCA gene 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. Mutated BRCA1 and BRCA2 genes are thought to increase the risk of breast and other cancers because these abnormal genes 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 Lynparza, which interferes with (inhibits) the PARP enzyme, makes it even harder for cancer cells with an abnormal BRCA1 or BRCA2 gene 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.
Lynparza is a capsule taken by mouth.
Lynparza is the first PARP inhibitor approved to treat breast cancer and is the first medicine approved to specifically treat breast cancers with a BRCA mutation.
The FDA’s approval of Lynparza to treat certain BRCA-mutation-linked breast cancers is based on the OlympiAD trial, which found that Lynparza improved progression-free survival by about 3 months compared to standard chemotherapy in women diagnosed with metastatic, HER2-negative breast cancer with a BRCA1 or BRCA2 mutation.
Progression-free survival is how long a woman lives without the cancer growing.
Like almost all cancer medicines, Lynparza can cause side effects, some of them severe.
Common side effects of Lynparza include:
- anemia (low red blood cell levels)
- neutropenia and leukopenia (low levels of certain white blood cells)
- cold or the flu
- respiratory tract infection
- joint pain
- changes in sense of taste
- decreased appetite
- mouth sores
Severe but less common side effects of Lynparza include:
- developing certain blood or bone marrow cancers
- inflammation in the lungs
“This class of drugs has been used to treat advanced, BRCA-mutated ovarian cancer and has now shown efficacy in treating certain types of BRCA-mutated breast cancer,” Richard Pazdur, M.D., the FDA's oncology chief, said in a statement. “This approval demonstrates the current paradigm of developing drugs that target the underlying genetic causes of a cancer, often across cancer types.”
If you’ve been diagnosed with metastatic HER2-negative breast cancer and know you have a BRCA1 or BRCA2 mutation, you may want to talk to your doctor about Lynparza ask whether it makes sense for your unique situation.
Breastcancer.org will keep you updated on future clinical trials looking at other inherited gene mutations and PARP inhibitors.
Editor’s Note: This article was updated on Jan. 24, 2019, with updated information on cancer risk associated with BRCA mutations.