PARP Inhibitors

Poly(ADP-ribose) polymerase (PARP) is an enzyme that helps repair DNA damage. PARP inhibitors are drugs that try to keep cancer cells from repairing damaged tumor DNA.

PARP inhibitors appear to hold the most promise for people who have a BRCA1 or BRCA2 inherited gene mutation [63,278-279,287].

Although PARP inhibitors have side effects, these drugs are often easier to tolerate than chemotherapy drugs.

Drug name

Brand name

Used to treat early or metastatic breast cancer?



Early and metastatic breast cancer



Metastatic breast cancer

Olaparib (Lynparza) and early breast cancer treatment

Olaparib (Lynparza) is FDA-approved for the treatment of HER2-negative early breast cancer at high risk of recurrence in people who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation and have been treated with chemotherapy.

Study findings have shown people with a BRCA1/2 gene mutation who had HER2-negative breast cancer at high risk of recurrence and got olaparib had a lower risk of breast cancer recurrence than those who didn’t get olaparib [279]. Olaparib was given after chemotherapy was completed [279].

Olaparib is a pill. It’s taken twice a day, every day for a year [288].

You start taking olaparib after you’ve completed chemotherapy (and after radiation therapy, if you’re getting radiation therapy) [288]. Olaparib may be taken at the same as hormone therapy [288].

Learn about survival and risk breast cancer recurrence after treatment.

Olaparib and BRCA1/2 genetic testing

Olaparib is only used to treat people with BRCA1/2 inherited gene mutations. So, you’ll need to get genetic testing for BRCA1/2 inherited gene mutations if olaparib is being considered in your treatment plan.

Learn about genetic testing and genetic counseling.

Learn more about BRCA1/2 inherited gene mutations.

Side effects of olaparib

Some possible side effects of olaparib include low red blood cell counts (anemia), low white blood cell counts, nausea, vomiting and fatigue [289]. In rare cases, it can cause acute myeloid leukemia [289].

Under study – PARP inhibitors and neoadjuvant therapy

Olaparib and another PARP inhibitor, talazoparib (Talzenna), each in combination with neoadjuvant chemotherapy (given before surgery), are under study for the treatment of early triple negative breast cancer [155-156].

Learn more about neoadjuvant therapy.

PARP inhibitors and metastatic breast cancer treatment

The PARP inhibitors olaparib (Lynparza) and talazoparib (Talzenna) are FDA-approved for the treatment of HER2-negative metastatic breast cancer in people who have a BRCA1 or BRCA2 inherited gene mutation.

Learn more about PARP inhibitors for the treatment of metastatic breast cancer.

Learn about emerging areas in treatment with PARP inhibitors for metastatic breast cancer.

Treatment guidelines

Although the exact treatment for breast cancer varies from person to person, guidelines help ensure high-quality care. These guidelines are based on the latest research and agreement among experts.

The National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO) are respected organizations that regularly review and update their guidelines.

In addition, the National Cancer Institute (NCI) has treatment overviews.

Talk with your health care team about which treatment guidelines they use.

Prescription drug assistance

Prescription drug costs can quickly become a financial burden for you and your family.

Medicare and many insurance companies offer prescription drug plans. One may already be included in your policy, or you may be able to buy an extra plan for prescriptions.

Olaparib (Lynparza) is a pill, so it’s covered under your health insurance plan’s prescription drug benefit rather than the plan’s medical benefit. This means there are usually out-of-pocket costs, which can add up over time.

You may qualify for programs that help with drug costs or offer low-cost or free prescriptions.

Learn more about insurance plans and prescription drug assistance programs.

Learn about other financial assistance programs.

Susan G. Komen®‘s position on fairness in oral cancer drug coverage

Insurance coverage of oral cancer drugs

Cancer medications given by vein (through an IV) are usually covered under a health insurance plan’s medical benefit. However, cancer medications that are pills (oral cancer drugs) are usually covered under a health insurance plan’s prescription drug benefit.

As a result, people often find themselves facing high out-of-pocket costs when filling prescriptions for oral cancer drugs. Sometimes this can cost thousands of dollars a month.

The impact of high cost-sharing

High prescription drug costs and the resulting out-of-pocket burden on patients are a barrier to care. They can prevent people from getting the medications prescribed by their health care providers.

No one should be forced to get less appropriate treatment because an insurer gives more coverage for IV drugs than pills.

Efforts to increase fairness in drug coverage

Komen supports state and federal efforts to require insurers to provide the same or better coverage for oral cancer drugs as they do for IV cancer drugs. This would help ensure patients have access to affordable, appropriate treatment.

Become a Komen Advocacy Insider

Sign up to be a Komen Advocacy Insider and get informed when action is needed on drug coverage issues at the state or national level.

Komen Financial Assistance Program

Susan G. Komen® offers the Komen Financial Assistance Program to eligible individuals undergoing breast cancer treatment at any stage or living with metastatic breast cancer (stage IV), the most advanced stage of breast cancer.

Financial assistance is available to those who meet pre-determined eligibility criteria.

To learn more about this program and other helpful resources, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email

Se habla español.

Clinical trials

Research is ongoing to improve all areas of treatment for breast cancer.

New therapies are being studied in clinical trials. The results of these studies will decide whether these therapies become part of standard care.

After discussing the benefits and risks with your health care provider, we encourage you to consider joining a clinical trial.

Learn what else Komen is doing to help people find and participate in breast cancer clinical trials, including trials supported by Komen.

Susan G. Komen® Breast Care Helpline

If you or a loved one needs information or resources about clinical trials, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email

Se habla español. in collaboration with Susan G. Komen® offers a custom matching service to help find clinical trials that fit your needs.

Learn more about clinical trials.


Komen Perspective

Read our perspective on clinical trials.*


  • If you or a loved one needs more information about breast health or breast cancer, contact the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or All calls are answered by a trained specialist or oncology social worker, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. Se habla español.
  • Komen Patient Navigators can help guide you through the health care system as you go through a breast cancer diagnosis. They can help to remove barriers to high-quality breast care. For example, they can help you with insurance, local resources, communication with health care providers and more. Call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email to learn more about our Patient Navigator program, including eligibility.
  • Komen Facebook groups provide a place where those with a connection to breast cancer can share their experiences and build strong relationships with each other. Visit Facebook and search for “Komen Breast Cancer group” or “Komen Metastatic Breast Cancer group” to request to join one of our closed groups.
  • Our fact sheets, booklets and other education materials offer additional information.

*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date. 

Updated 03/17/22