Ovarian Cancer Treatment Update and Pharmacists' Role

Drug Topics Journal, Drug Topics September 2021, Volume 165, Issue 9

New targeted therapies known as PARP inhibitors (PARPis) used to treat patients with advanced ovarian cancer are transforming the treatment landscape through precision medicine.

Pharmacists can play a key role in treating patients with ovarian cancer through counseling, drug information consults, and adherence. September is Ovarian Cancer Awareness Month and an important time to educate patients about the latest treatments and research.2 New targeted therapies known as PARP inhibitors (PARPis) used to treat patients with advanced ovarian cancer are transforming the treatment landscape through precision medicine.3


Treatment and Research Updates

PARPis are a type of targeted therapy, and there are 3 FDA-approved medications in this class taken orally for the treatment of ovarian cancer: olaparib (Lynparza), rucaparib (Rubraca), and niraparib (Zejula).4-6

PARPis work by preventing cancer cells from repairing. The National Comprehensive Cancer Network indicates for post primary treatment that certain patients with newly diagnosed stage II-IV disease may benefit from maintenance therapy with PARPis if a complete or partial response is achieved after primary treatment with surgery and platinum-based first-line therapy.7 There also are promising drugs in the pipeline from different classes being studied for the treatment of ovarian cancer. Studies are now examining the causes of racial and ethnic disparities among women with ovarian cancer. These studies aim to examine disparities in patient care and survival.8 The ACS research programs are evaluating ovarian cancer topics such as diagnosis, prevention strategies, and effective treatment options.9

One long-running study from the Dana-Farber Cancer Institute and cofunded by the Ovarian Cancer Research Alliance found that the antibiotic novobiocin can target and kill tumor cells in laboratory cell lines and tumor models with BRCA1 or BRCA2 genetic mutations. It is also effective in tumors that have become resistant to PARPis.10

One recent study showed that the PARPi rucaparib is effective in treating certain types of ovarian cancers if used early in treatment, before the cancer builds resistance to chemotherapy.11 Researchers at the University of Alabama at Birmingham identified a gene called DOT1L, and inhibitors of the DOT1L enzyme could be a new approach to treating ovarian cancer.

Researchers examined patient data and found that DOT1L expression was much higher in tissues from patients with ovarian cancer compared with tissues from healthy patients.

Patients with ovarian tumors that had high DOT1L expression showed shorter progression-free survival and shorter overall survival rates compared with patients whose ovarian tumors had lower DOT1L expression.12

Pharmacists’ Role in Ovarian Cancer Management

Pharmacists can aid in monitoring patients on PARPi therapy and determining the appropriate dose based on renal function, adverse reactions, and potential drug interactions. Patients with renal impairment require a dose reduction with olaparib, but not for niraparib and rucaparib.5,6 The starting dose for niraparib should be reduced in patients with moderate hepatic impairment, and further dose reductions may be needed.6

The NCCN recommends that patients receiving PARPi therapy have careful monitoring of blood counts and renal and hepatic function.7 Blood pressure monitoring is required for niraparib and recommended for all other PARPis.7

Pharmacists can provide medication therapy management services, such as patient counseling, refill synchronization, and follow-up.