Using PARP Inhibitors Earlier
- Women with BRCA mutations benefit the most from PARP inhibitors– which include the brands Lynparza, Rubraca, and Zejula.
- Regardless of BRCA status, almost all women are eligible to take these drugs after a response to chemo.
- PARP inhibitors have very real side effects that should be discussed with your doctor.
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.
Read MoreHow PARP Inhibitors Work
PARP inhibitors interrupt the process of single stranded DNA repair, an essential part of cell replication. Defects in DNA repair ultimately cause cell death. For the regular person just trying to understand their options, keeping cancer cells from making copies of themselves helps shrink the disease, or at least keep it at bay.- PARP inhibitors work best when there is a second error in DNA repair, such as that caused by a mutation in the BRCA gene.
- BRCA is a critical player in homologous recombination, a highly-effective double stranded DNA repair process. BRCA is not the only important part of homologous recombination, other genes are involved. The label homologous recombination deficient (HRD) indicates a tumor which has one of many possible errors in the double stranded DNA repair process of homologous recombination. Again, the language of regular people, HRD positivity (or proficiency) means that a woman's ovarian cancer cells have trouble repairing themselves. And this can make them somewhat easier to fight.
- Ovarian cancer patients with a lot of homologous recombination deficiencies exhibit specific clinical behaviors, and improved responses to treatments, such as platinum-based chemotherapy and PARP inhibitors, according to researchers.
Quick Summary Of How PARP Inhibitors Are Used & Current Approvals
- Zejula (niraparib) had previously been used to treat women at a later stage of treatment, but the drug is now available earlier and to more women than before. Zejula is approved for all women with newly-diagnosed ovarian cancer regardless of whether the tumor is HRD. Niraparib, like other PARP inhibitors, is given in pill form. Several PARP inhibitors have been approved for the treatment of ovarian cancer over the past several years.
- Doctors caution that without a BRCA mutation, there can be very limited effectiveness from taking a PARP and this is really something to evaluate with your physician.
- 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 women and their oncologists need to evaluate carefully.
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