PARP Inhibitors Keep Ovarian Cancer Under Control, But Women on These Drugs Need Support to ‘Set Them Up for Success’

Poly(ADP)-ribose polymerase (PARP) inhibitors are among the newest tools in oncologists’ arsenal against ovarian cancer. These breakthrough targeted drugs have had dramatic effects on progression-free survival.

Having these drugs available to women with ovarian cancer is “very exciting,” Kathleen Lutz, a nurse practitioner at NYU Langone Health, tells SurvivorNet. “It’s a great way to maintain and treat the cancer, and give patients a good quality of life.”

But for women who take PARP inhibitors, treating their cancer comes at the cost of sometimes life-altering side effects, such as fatigue, nausea, and low red blood cell counts (anemia).

Related: New Guidelines on the Use of PARP Inhibitors Help Doctors & Women With Ovarian Cancer Make Smarter Decisions

How PARP Inhibitors Work

Three PARP inhibitors are FDA-approved to treat women with epithelial ovarian cancers:

• Olaparib (Lynparza)
• Niraparib (Zejula)
• Rucaparib (Rubraca)

These drugs work by preventing ovarian cancer cells from repairing their damaged DNA. When the cancer cells can’t fix themselves, they can no longer grow or spread. PARP inhibitors are particularly effective in women with BRCA1 and BRCA2 mutations, which also thwart the cancer cells’ ability to fix their own DNA and make them even more likely to die when exposed to PARP inhibitors. Yet PARP inhibitors are also effective in women without BRCA gene mutations.

Related: PARP Inhibitors for Ovarian Cancer: How They Work

The Reality of PARP Inhibitor Side Effects

Unfortunately, taking PARP inhibitors isn’t an entirely rosy experience for some women. Tiredness and nausea are among the most common side effects, Lutz says. So some women can expect to feel pretty lousy when they start taking PARP inhibitors.

Because PARP inhibitors disrupt cells’ repair process, they can also be harmful to blood cells. One victim of this collateral damage is the red blood cells that transport oxygen throughout your body. The loss of these cells can lead to anemia, which can leave you pale, weak, tired, and short of breath. Some women get low in platelets, the blood cells that help form clots to stop the bleeding after an injury.

Are PARP inhibitors right for you? Dr. John Nakayama, gynecologic oncologist at University Hospitals in Cleveland, explains which patients are eligible for these drugs

That’s the bad news. The good news is most, if not all of these side effects shouldn’t stick with you for long. “Within a few months, typically most patients have recovered,” Lutz says.

Making Predictions: Which Side Effects Might You Have?

Another upside is that doctors can pull out their figurative crystal balls and do some prognosticating about what your side effect future might hold. “We have to look at where they are in terms of their chemo history — what recent treatments they’re coming off of, and then we can kind of gauge what side effects might occur,” Lutz says.

Once your treatment team has an idea of what issues you might face, such as nausea, they have ways to stop these side effects before they can bother you.

“I set them up for success well before we start the drug,” Lutz says. “We teach our patients how to manage nausea by eating a small meal beforehand, taking some anti-nausea medication. We try some non-medicinal things like teas…and just a lot of psychological support in general.” When her patients first go on PARP inhibitors, she’ll see them at least once a month and talk to them once a week.

“A lot of support around PARP inhibitors is needed for success,” she adds. “But it’s a great way to treat and keep a lot of our patients cancer-free,” she adds.

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