Who Can Receive PARP Inhibitors?

According to Dr. Oliver Dorigo, a gynecologic oncologist at Stanford Medical School, this traditional approach shows that PARP inhibition is “particularly effective in those patients with BRCA mutations.” Tumor cells with these mutations have problems repairing DNA already, and the PARP inhibitors make that worse, causing cancer cells to die. Patients can either have the BRCA mutation in all the cells in their body, known as a germline mutation, or in just their tumor cells, known as a somatic mutation.

Here’s the quick summary of who may be eligible for PARP inhibitors, according to the experts:

1. Maintenance Therapy For Newly-Diagnosed Epithelial Ovarian Cancer:  

During this phase, PARP inhibitors help maintain ovarian cancer in its depleted state following chemotherapy, extend the length of time before a new recurrence emerges, and sometimes even turn a temporary remission into a long-term cure.

• The PARP inhibitor Zejula (niraparib) has been approved by the FDA for all women with newly-diagnosed ovarian cancer regardless of BRCA or HRD status. The drug is used after successful treatment with a platinum-based chemotherapy, the mainstay chemotherapy for ovarian cancer.
• Due to limited benefit in progression free survival seen in the absence of HRD, gynecologic oncologists differ on whether PARP inhibitors should be universally recommended in the "upfront maintenance setting." Each patient should be made aware of risks and benefits to PARP inhibitor maintenance and decide with their oncologist what is the best treatment plan for them.
• The PARP inhibitor Lynparza (olaparib) is approved for women newly diagnosed with ovarian cancer and with a germline or somatic mutation in BRCA1/2.
• Lynparza is also approved in combination with Avastin (bevacizumab) for women with HRD.  Avastin is a blood vessel growth inhibitor, which works by starving the tumor of vital nutrients needed to grow.

2. Recurrence

Unfortunately, recurrence is part of ovarian cancer for many women.

For women with ovarian cancer who have had a recurrence and responded to platinum-based chemotherapy, Lynparza, Zejula and another PARP inhibitor called Rubraca (rucaparib) are FDA approved for use as a maintenance therapy, regardless of whether a woman has a BRCA mutation or HRD. For some women who have had prior chemotherapy treatments, Rubraca, Zejula or Lynparza may also be options. These uses are based on factors such as number of prior therapies and BRCA mutation or HRD.

The different PARP inhibitors do have some varying side effects, which women and their doctors need to evaluate carefully. It’s important to ask your doctor if he or she has experience managing the side of effects for the various PARPs. Some of these considerations are explained here.

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