Maintenance therapy for ovarian cancer is medication that’s given to prevent ovarian cancer from coming back after initial treatment with chemotherapy. The goal is to increase the amount of time between initial treatment and recurrence.
The Food and Drug Administration (FDA) has approved the following treatments for ovarian cancer maintenance therapy:
- PARP (poly ADP-ribose polymerase) inhibitors
- angiogenesis inhibitors, such as bevacizumab
Your doctor will recommend maintenance therapy in an effort to increase the amount of time between initial treatment with chemotherapy and relapse of the condition.
Your doctor prescribes maintenance therapy with bevacizumab after you’ve completed chemotherapy following the initial diagnosis of stage 3 or 4 ovarian cancer. They may also recommend it if you have recurrent ovarian cancer that’s sensitive to platinum chemotherapy.
PARP inhibitors are used as maintenance therapy after initial chemotherapy if you have advanced stage ovarian cancer. Your doctor may recommend a PARP inhibitor if you have a complete or partial response to chemotherapy in recurrent ovarian cancer, regardless of your BRCA mutation status.
Bevacizumab and the PARP inhibitor olaparib can be taken together as maintenance therapy after upfront treatment with chemotherapy and bevacizumab.
Your doctor may recommend this if you’re responding to first-line platinum chemotherapy and cancer is related to “homologous recombination deficiency” positive status.
For background, homologous recombination deficiency is the inability to pair double-stranded breaks in your DNA. This can occur with a BRCA gene mutation or another mutation that causes genetic instability.
PARP is an enzyme in your cells that repairs your DNA when it becomes damaged. PARP inhibitors are drugs that block the PARP within cells. Disabling PARP in cancer cells prevents the cell from repairing its DNA and causes the cell to die.
PARP inhibitors are oral drugs that can be taken with or without food. They’re taken once or twice daily depending on the PARP inhibitor that’s prescribed.
FDA-approved PARP inhibitors for the treatment of ovarian cancer include:
Blood vessels support tumor growth. Angiogenesis inhibitors are a class of drugs that fight cancer by blocking the ability of cells to form new blood vessels. Numerous angiogenesis inhibitors treat a variety of cancers.
Bevacizumab was initially approved by the FDA in 2004 for the treatment of metastatic colon cancer. It was later approved for use with chemotherapy in people with recurrent ovarian cancer that’s resistant to platinum chemotherapy.
Angiogenesis inhibitors such as bevacizumab work by attaching to vascular endothelial growth factor (VEGF). This prevents it from interacting with the VEGF receptor on cell surfaces. Blocking this interaction prevents cancer cells from making new blood vessels from those that already exist.
Angiogenesis inhibitors such as bevacizumab are given with an intravenous (IV) infusion every 2 to 3 weeks. The frequency depends on your tumor type and the type of chemotherapy you receive.
The most common side effects of angiogenesis inhibitors include:
- elevated blood pressure
- elevated protein levels in urine
- rarely, blood clots or bleeding
Your doctor can help you to manage these side effects with medications to help control your blood pressure and nausea.
PARP inhibitors often lower blood counts. This can result in:
- low white blood cell counts
- low platelets
- musculoskeletal pain
- poor appetite
- abdominal discomfort
Low platelets may lead your doctor to withhold PARP inhibitors until your blood counts return to normal.
Maintenance therapy with angiogenesis inhibitors and PARP inhibitors has been shown to extend the time between the completion of chemotherapy and the relapse of ovarian cancer.
PARP inhibitors in particular improve progression-free survival regardless of a BRCA mutation. Progression-free survival is the amount of time that a person treated for cancer lives with the disease without it getting worse.
Maintenance therapy continues as long as you tolerate the medication well and are showing signs of excellent disease control.
Dr. Krystal Cascetta is a board certified internal medicine physician specializing in hematology and medical oncology. She is a practicing physician at the Mount Sinai Hospital in New York, specializing in breast cancer and clinical quality. Dr. Cascetta received her MD from Albany Medical College at Albany, New York. She completed a fellowship in hematology and medical oncology at the Mount Sinai Hospital. Additionally, she completed a clinical quality fellowship with the Greater New York Hospital Association and the United Hospital Fund.