Olaparib

Olaparibinfo-icon (Lynparza) is a targeted therapyinfo-icon approved by the Food and Drug Administrationinfo-icon. It is used to treat early-stageinfo-icon or metastaticinfo-icon breast cancer that is either hormone receptorinfo-icon-positive and HER2-negative, or triple-negative, in people with an inheritedinfo-icon BRCA geneinfo-icon mutationinfo-icon who have already been treated with chemotherapyinfo-icon.

Olaparib was the first PARP inhibitorinfo-icon to be FDAinfo-icon approved in breast cancer. It was also the first medicineinfo-icon approved specifically for people who have breast cancer and an inherited (also called germline) BRCA mutation. The FDA initially approved it for use in ovarian cancerinfo-icon in 2014. Olaparib is now used to treat breast, pancreatic, and prostate cancers as well.

How olaparib works

Olaparibinfo-icon is a PARP inhibitorinfo-iconPARPinfo-icon (or poly (ADP-ribose) polymerase) is an enzyme in the body that helps repair DNA damage to cells, even cancer cells. DNA damage can occur for any number of reasons. PARP inhibitors treat cancer by stopping PARP from repairing cancer cellinfo-icon DNA. Instead, cancer cells die. People with inheritedinfo-icon BRCA mutations are more likely to respond to PARP inhibitors because their cells are already less able to repair themselves.

In a clinical trialinfo-icon, researchers found that participants with metastaticinfo-icon breast cancer who took olaparib went about 3 months longer without the cancer growing or spreading than participants who got standard chemotherapyinfo-icon. The cancer was also about twice as likely to shrink in those who took olaparib.

A more recent clinical trial found that olaparib given for one year after standard treatment also has benefit for people with high-risk early-stage breast cancerinfo-icon who tested positive for an inherited BRCA mutationinfo-icon. After three years of follow-up, 86% of participants who took olaparib for a year were still cancer-free, compared with 77% of participants who did not take olaparib. Both groups had at least six cycles of chemotherapy before starting olaparib.

Who gets olaparib

Olaparibinfo-icon is approved for use in people who test positive for a BRCA1info-icon or BRCA2info-icon geneinfo-icon mutationinfo-icon inheritedinfo-icon from a parent. It is now FDAinfo-icon approved for both high-risk early-stageinfo-icon and metastaticinfo-icon breast cancers that are HER2-negative. The cancer can be either hormone receptorinfo-icon-positive or triple-negative. 

You must have already been treated with chemotherapyinfo-icon to get olaparib. If you have high-risk early-stage breast cancerinfo-icon, you likely will have had surgeryinfo-icon as well. It does not matter if chemotherapy was given before or after surgery. People with hormone receptor-positive early-stage breast cancer will continue to take hormonal therapyinfo-icon while on olaparib.

The only way to know if you were born with a BRCA mutation is to get genetic testinginfo-icon for an inherited mutation. This testing is done using a blood, saliva, or cheek-swab test. The FDA recently approved the BRACAnalysis CDx test for people with high-risk, early-stage HER2-negative breast cancer who have not had genetic testing for an inherited mutation. This faster turnaround test can identify people with the BRCA gene mutation who may benefit from olaparib. If you are interested in this test or in genetic testing in general, talk with your doctor.

“The use of olaparib for both early-stage and advanced breast cancer now calls for all patients who qualify for this therapyinfo-icon to be tested for BRCA 1 and 2,” says Debu Tripathy, MD. “Research is ongoing to see if olaparib can also be used for patients with acquired (also known as somaticinfo-icon) BRCA mutations that are not inherited, but only found in the tumorinfo-icon DNA, or for mutations other than BRCA 1 or 2 that are involved in DNA repair.”

How olaparib is given

Olaparibinfo-icon is a pill. It is usually taken twice every day, at least 12 hours apart, with or without food. The pill must be swallowed whole, not crushed, dissolved, chewed, or divided. It is important to take these pills as prescribed. If you happen to miss a doseinfo-icon, just take the usual dose at the next scheduled time. Do not take a double dose.

Side effects and things to remember

In a clinical trialinfo-icon, researchers found olaparibinfo-icon had fewer serious side effects overall than standard chemotherapyinfo-icon. Its most common serious side effects are low blood cellinfo-icon counts, which can cause fatigueinfo-icon and increase the risk of infectioninfo-icon. Rarely, low blood cells counts while taking PARPinfo-icon inhibitors are a sign of serious problems in the bone marrow, areas of fatty tissueinfo-icon in the bones in which blood cells are made. Because of this, your health care providers should do blood tests before you begin treatment with olaparib, and throughout your treatment with it.

Other common side effects include

  • nauseainfo-icon and vomiting
  • tiredness or weakness
  • sore throat or runny nose
  • diarrheainfo-icon
  • joint, muscle, and back pain
  • headache
  • constipation
  • changes in the way food tastes
  • loss of appetite
  • mouth sores

Rarely, PARP inhibitors may cause serious lung problems. Though it’s unlikely you’ll have serious lung problems while taking olaparib, if you feel new or worsening shortness of breath, fever, coughing, or wheezing, tell your doctor right away.

Tell your doctor about any medicines, supplements, or herbal remedies you are taking before starting olaparib. Avoid eating or drinking any food with grapefruits, and a type of orange called a bitter orange or a Seville orange, which is often used in marmalade. These fruits can affect the way your body absorbs olaparib.

Tell your doctor if you are pregnant, breastfeeding, or planning to become pregnant or start breastfeeding. Olaparib may be dangerous to a fetus so it is recommended that you not take this medicineinfo-icon while pregnant. It is also advised that you avoid getting pregnant until at least 6 months after you have stopped treatment with it. It is not known if olaparib is transferred through breast milk, so you should not breastfeed while taking olaparib or for 1 month after you stop treatment.

Talk to your doctor about any side effects you experience and how to manage them.

Updated 
May 22, 2022
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