Adding the PARP inhibitor Lynparza (chemical name: olaparib) to standard treatment for early-stage HER2-negative breast cancer with a high risk of recurrence in people with a BRCA1 or BRCA2 mutation improved disease-free survival, according to results from the OlympiA study.
Disease-free survival is how long a person lives without the breast cancer coming back.
The research was presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting and was published online on June 3, 2021, by the New England Journal of Medicine:
- Read the ASCO abstract of “OlympiA: A phase III, multicenter, randomized, placebo-controlled trial of adjuvant olaparib after (neo)adjuvant chemotherapy in patients with germline BRCA1/2 mutations and high-risk HER2-negative early breast cancer.”
- Read the New England Journal of Medicine abstract of “Adjuvant Olaparib for Patients with BRCA1- or BRCA2-Mutated Breast Cancer.”
Most inherited cases of breast cancer are associated with two gene mutations: BRCA1 and BRCA2. Women with a mutated BRCA1 or BRCA2 gene have up to a 72% risk of developing breast cancer by age 80. Their risk of developing ovarian cancer also is higher than average. Men with a BRCA gene mutation have a higher risk of developing 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). But cells can detect and repair damage to DNA. When a healthy cell’s DNA is damaged and not fixed, the 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 a healthy cell’s ability to repair damaged DNA and to prevent cancer growth.
The poly-adenosine-diphosphate-ribose polymerase (PARP) enzyme fixes DNA damage in both healthy cells and cancer cells. Lynparza interferes with — or inhibits — the PARP enzyme and prevents cancer cells with a BRCA1 or BRCA2 mutation from fixing DNA damage and surviving. In other words, a PARP inhibitor makes some cancer cells less likely to survive their DNA damage.
Right now, Lynparza — a pill taken by mouth — is approved to treat metastatic HER2-negative breast cancer with an inherited BRCA1 or BRCA2 mutation that has previously been treated with chemotherapy.
Because Lynparza helps treat metastatic breast cancer with a BRCA1/2 mutation, researchers wondered if it could offer benefits for early-stage disease with the same mutations.
About the study
Called the OlympiA trial, the study included 1,836 people diagnosed with early-stage HER2-negative breast cancer with a high risk of recurrence. All the people — 1,830 women and 6 men — had a BRCA1 or BRCA2 mutation.
The study was done between June 2014 and May 2019.
- about half the people were younger than 42.5 years and half were older
- 72.3% of the people had a BRCA1 mutation
- 27.2% of the people had a BRCA2 mutation
- 0.4% of the people had both a BRCA1 and a BRCA2 mutation
- 82.2% of the people had triple-negative breast cancer (estrogen-receptor-negative, progesterone-receptor-negative, and HER2-negative)
- about 17.4% of the people had hormone-receptor-positive breast cancer and also were treated with hormonal therapy
- 50% of the people had received chemotherapy before surgery (neoadjuvant chemotherapy)
- 50% of the people had received chemotherapy after surgery (adjuvant chemotherapy)
- 93.7% of the people had received a chemotherapy regimen that included both an anthracycline and a taxane
- about 74% of the people had surgery to remove the breast cancer
Anthracycline chemotherapy medicines include:
- Adriamycin (chemical name: doxorubicin)
- Ellence (chemical name: epirubicin)
- Doxil (chemical name: liposomal doxorubicin)
- mitoxantrone (brand name: Novantrone)
Anthracyclines work by damaging cancer cells’ genes and interfering with their reproduction.
Taxane chemotherapy medicines include:
- Taxotere (chemical name: docetaxel)
- Taxol (chemical name: paclitaxel)
- Abraxane (chemical name: albumin-bound or nab-paclitaxel)
Taxanes work by interfering with the ability of cancer cells to divide.
After the participants completed chemotherapy — considered the standard of care for this type of breast cancer — the researchers randomly assigned them to one of two treatment groups:
- 921 people took Lynparza twice a day for 1 year
- 915 people took a placebo, a pill that looked just like Lynparza but contained no medicine, twice a day for 1 year
After about 2.5 years of follow-up:
- 85.9% of the people who took Lynparza were alive with no cancer recurrence
- 77.1% of the people treated with just the standard of care (the placebo group) were alive with no cancer recurrence
This difference was statistically significant, which means that it was likely because of the difference in treatment and not just because of chance.
People treated with Lynparza also were less likely to have a metastatic recurrence. Doctors call this distant disease-free survival. Metastatic recurrence is when the cancer comes back in a part of the body away from the breast, such as the bones or liver.
Distant disease-free survival rates were:
- 87.5% for people in the Lynparza group
- 80.4% for people in the placebo group
“The OlympiA study is the first study to report the benefits of a PARP inhibitor, olaparib, as an adjuvant treatment for early forms of germline BRCA-associated cancer,” said lead researcher Andrew Tutt, MB, Ch.B., Ph.D., of the Institute of Cancer Research and Kings College London during a media briefing at the ASCO Annual Meeting. “Patients who received olaparib after surgery and chemotherapy were more likely to be alive without cancer and avoid metastasis than the patients who received placebo.”
Lynparza side effects
The researchers looked at the side effects reported by 1,815 of the study’s participants: 911 in the Lynparza group and 904 in the placebo group.
Like almost all cancer medicines, Lynparza can cause side effects, some of them serious.
The most common side effects caused by Lynparza in the study were:
- anemia (low red blood cell counts)
- low white blood cell counts
- loss of appetite
- joint pain
Other studies on Lynparza have reported the same side effects. This study found no new side effects.
Rates of serious side effects were similar between the two treatment groups.
What this means for you
If you have been diagnosed with early-stage HER2-negative breast cancer with a high risk of recurrence and have a BRCA1 or BRCA2 mutation, the results of this study are promising.
While Lynparza is not yet approved to treat early-stage disease, AstraZeneca and Merck, the companies that make Lynparza, have said they are working with regulatory agencies to get Lynparza approved to treat early-stage disease.
If you have been diagnosed with early-stage HER2-negative breast cancer with a high risk of recurrence and don’t know if you have a BRCA1 or BRCA2 mutation, consider asking your doctor whether genetic testing makes sense for you to see if you could benefit from Lynparza treatment.
Stay tuned to Breastcancer.org Research News for the latest information on Lynparza approval updates.
Written by: Jamie DePolo, senior editor
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