A growing number of women diagnosed with epithelial ovarian cancer are eligible for treatment with a class of drugs called PARP inhibitors. PARP inhibitors are options for women as maintenance therapy after first chemotherapy or platinum sensitive recurrence, or as treatment for recurrence. The benefit a woman may see from this class of medication varies greatly, with the biggest determinant being the presence of an inherited or tumor mutation in BRCA.
How PARP Inhibitors Work
One of the key things to know about PARP inhibitors is that your genetic makeup and specific features of your cancer will have a significant impact on how effective these drugs may be. Experts tell SurvivorNet that every woman with ovarian cancer should get a genetic test to determine if they have a mutation called BRCA, because the mutation enables PARP inhibitors to function much more powerfully. Importantly, there is increasing data that even women without BRCA mutations can still derive some benefit from these drugs.
Read MoreNewly-Diagnosed Epithelial ovarian cancer
The PARP inhibitor Zejula (niraparib) has been approved by the FDA for all women with newly-diagnosed ovarian cancer irrespective of whether the tumor is HRD. 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.
Using PARPs To Treat Recurrence
Unfortunately, too often, ovarian cancer comes back.
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 oncologists need to evaluate carefully. Some of these considerations are explained here.
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