Rucaparib Promising Agent for Patients With Relapsed Ovarian Cancer

Elizabeth Swisher, MD

Rucaparib, a PARP inhibitor, has shown promising activity in patients with relapsed, platinum-sensitive, high-grade, ovarian cancer, according to findings from the ARIEL2 study presented at the Society for Gynecologic Oncology (SGO) 48th Annual Meeting in National Harbor, Maryland.  

In December 2016, the FDA granted an accelerated approval to rucaparib as a treatment for patients with BRCA-positive advanced ovarian cancer who have received at least two prior lines of chemotherapy. Rucaparib is part of the class of drugs known as PARP inhibitors; blocking PARP may help keep cancer cells from repairing their damaged DNA, causing them to die. Rucaparib is also being explored in prostate, breast, and gastroesophageal cancers.

The findings reported at the SGO meeting stem from a subgroup analysis of the phase II ARIEL2 trial. In this study, Elizabeth Swisher, MD, and colleagues sought to determine whether patients whose tumors exhibited BRCA1 or RAD51C promoter hypermethylation might have a better response to rucaparib.

They found that objective responses with rucaparib occurred in more than half of patients whose tumors exhibited BRCA1 promoter methylation and in 3 of 4 patients with RAD51C promoter methylation.

In the ARIEL clinical trial program upon which the FDA approval was based, the most common grade 3/4 adverse events reported in patients on the study drug were anemia/decreased or low hemoglobin, observed in 25 percent of patients.  

During the SGO meeting, Swisher, a professor of gynecologic oncology and adjunct professor in medical genetics at the University of Washington, and director of the Breast and Ovarian Cancer Prevention Program at the Seattle Cancer Care Alliance, discussed the trial in an interview withTargeted Oncology.

TARGETED ONCOLOGY:What was the quality of life for patients in this study?

Swisher:

Quality of life was pretty good. There was some toxicity; about half of the patients reduced the dose of drug because they were experiencing toxicity, but very few patients came off treatment because of toxicity. Thus, most patients really tolerated the treatment quite well. Only about 13% of patients stopped therapy, because they were having toxicity that they couldn't tolerate.

TARGETED ONCOLOGY:Were there any side effects that patients should be aware of?​

Swisher:

The most common side effects are nausea, sometimes with vomiting, and fatigue, and sometimes they have some laboratory abnormalities that are not very serious. Anemia is among the known side effects of rucaparib. What's important for patients to understand is that in the first month of the treatment, people experience more nausea, more fatigue, but those symptoms do get better. If patients can understand that they need to get past that initial stage, and it's not what they're going to have to experience during the whole course of treatment, I think that's helpful. And we have to be pretty proactive with giving patients medications for nausea, for example, to get them through this difficult period. Often, they don't need anti-nausea medications down the road.

TARGETED ONCOLOGY:Is there a certain group of patients who responded better in the study?​

Swisher:

So the patients who responded the best were patients who had inherited mutations inBRCA1orBRCA2, or they had tumor mutations inBRCA1orBRCA2, so that would be identified by sequencing the tumor. Those patients definitely had the highest response rates and the longest responses.

TARGETED ONCOLOGY:What are some of the main takeaways you'd like patients to know about the trial?​

Swisher:

There are alternatives to chemotherapy now that patients are considering, and if your ovarian cancer recurs, you need to sit down with your oncologist and say, "What are all my options?" Going back on the same chemotherapy is not the only option anymore. Many patients want to postpone going on a toxic chemotherapy if they can go on to something less toxic. And you can come back to that chemotherapy later if you need it. But a lot of patients, from a quality of life perspective, would rather consider alternatives.  

Finally, if you have ovarian cancer and have not had genetic testing, that's something we recommend for all women with ovarian cancer.