PARP inhibitors: Their function, applications, and available choices
In the realm of cancer treatment, a group of drugs known as PARP inhibitors have gained significant attention due to their targeted approach. These drugs, including olaparib, niraparib, rucaparib, and talazoparib, are approved by the Food and Drug Administration (FDA) for the treatment of various types of cancer.
PARP inhibitors are targeted therapies, meaning they primarily affect cancer cells while having less impact on healthy cells compared to traditional chemotherapy. They work by blocking the action of PARP enzymes, which are responsible for repairing DNA damage in cells. This targeted action can help slow down or stop the growth of cancer cells.
Ovarian, fallopian tube, primary peritoneal, and prostate cancers are among the cancers that can be treated with PARP inhibitors, such as rucaparib, which may be used in the maintenance period following chemotherapy. Olaparib, on the other hand, can help treat ovarian cancer, fallopian tube cancer, or primary peritoneal cancer, as well as BRCA-associated metastatic breast cancer.
Talazoparib is prescribed for adults with BRCA1 or 2 mutations and metastatic breast cancer. Niraparib has similar uses to rucaparib for ovarian cancer, fallopian tube cancer, and primary peritoneal cancer, but not prostate cancer. Doctors may prescribe niraparib after at least three rounds of chemotherapy.
It is crucial to discuss the possible side effects and interactions of any PARP inhibitor with a doctor before starting the treatment. Side effects may include diarrhea, fatigue, nausea, vomiting, a loss of appetite, changes in taste, stomach pain, muscle and joint pain, and reduced levels of red blood cells, white blood cells, and platelets. The doctor can describe how to manage any side effects, what to do if side effects are severe, and in which circumstances it is a good idea to stop the treatment.
In rare cases, PARP inhibitors can cause cancer to develop in the blood. It is essential to let the doctor know about any other medications, remedies, or supplements, as some may interfere with the effectiveness and safety of PARP inhibitors.
More PARP inhibitors are in development, offering hope for further advancements in cancer treatment. A person might ask about drug label warnings and any other risks involved when discussing PARP inhibitors with a doctor.
It is worth noting that niraparib is unique as it is FDA-approved for maintenance therapy in ovarian cancer patients without requiring BRCA mutation or HRD positivity, distinguishing it from others that typically require these biomarkers. In prostate cancer, niraparib combined with abiraterone and corticosteroids (Akeega) is an emerging therapy for patients with HRR alterations in the metastatic hormone-sensitive setting, with regulatory submissions underway in Europe as of July 2025.
All PARP inhibitors require careful patient selection based on genetic testing (e.g., BRCA, HRD, or HRR gene status) due to their mechanism targeting tumors with defective DNA repair pathways. The National Comprehensive Cancer Network (NCCN) guidelines updated in 2025 reflect expanded roles for niraparib maintenance in ovarian cancer beyond BRCA-mutated cases, emphasizing its usage in HRD-positive patients as well.
In summary, olaparib, niraparib, rucaparib, and talazoparib are each approved for various cancers, primarily ovarian, breast, and prostate cancers with homologous recombination DNA repair defects, with niraparib notable for broader approval in ovarian cancer maintenance regardless of BRCA mutation status and emerging combination indications in prostate cancer.
- The targeted therapy, talazoparib, is prescribed for adults with BRCA1 or 2 mutations and metastatic breast cancer, while niraparib is FDA-approved for maintenance therapy in ovarian cancer patients, unlike others, without requiring BRCA mutation or HRD positivity.
- Science continues to advance in the field of health-and-wellness, with more PARP inhibitors under development, offering hope for further advancements in cancer treatment, including the emerging therapy for prostate cancer patients with HRR alterations using niraparib combined with abiraterone and corticosteroids.
- When discussing medical-conditions like peritonitis or cancer with a doctor, it is essential to consider options like PARP inhibitors, such as olaparib, niraparib, rucaparib, and talazoparib, and discuss their possible side effects, interactions, and appropriate use based on genetic testing.
