Olaparib as Maintenance Drug Reduces Disease Progression for Advanced Ovarian Cancer

In women with advanced ovarian cancer, olaparib used as maintenance therapy for 2 years after primary treatment significantly lengthens 5-year progression-free survival, according to a study presented at the Society of Gynecologic Oncology 2021 Virtual Annual Meeting on Women’s Cancer.

“Even years after patients completed the planned 2 years of olaparib treatment, their progression-free survival benefit endured,” said the study’s lead author, William Bradley, MD, a gynecologic oncologist at Froedtert and Medical College of Wisconsin, Milwaukee in a press release. “That’s very good news.”

Olaparib is an oral targeted chemotherapy drug known as a PARP inhibitor, and it stops the cell’s PARP enzyme from repairing DNA damage, which makes it important in cancer progression.

The study evaluated 5 years of follow-up data from a prior study, which Bradley called “the longest follow-up for any PARP inhibitor in the setting of maintenance therapy after primary therapy.”

The objective of maintenance therapy is to slow the cancer’s growth after initial treatment, usually with platin-based chemotherapy and surgical treatment. Olaparib was studied in patients with a mutation, or harmful alteration, of the BRCA1 and/or BRCA2 genes, and the mutation is present in about 1/4th of women with ovarian cancer, according to Bradley.

The study data came from the SOLO-1 clinical trial, initially published in 2018, which included 391 patients with a BRCA mutation and newly diagnosed advanced ovarian cancer who first completed platin-based chemotherapy. The SOLO-1 trial randomly assigned 260 women to receive olaparib and 131 to get a placebo for 2 years or until the cancer worsened.

The analysis found that more than twice as many women who received olaparib were still alive 5 years after the beginning of the study with no progression of their cancer. More than 48% of olaparib recipients had 5-year progression-free survival versus only 20.5% of placebo recipients, according to the study authors.

Further, the researchers analyzed subgroups of patients depending on their risk of disease progression, and compared with placebo, olaparib recipients had better 5-year progression-free survival regardless of their initial progression risk.

“Olaparib maintenance therapy should be a standard of care for women with a BRCA mutation and advanced ovarian cancer,” Bradley said in the press release.

Potential side effects of olaparib include blood abnormalities, and Bradley suggests that patients taking olaparib should receive routine physical assessments and lab tests under an oncologist’s care.

REFERENCE

For advanced ovarian cancer, olaparib as maintenance drug reduces disease progression, five-year follow-up data show. March 20, 2021. Accessed March 22, 2021. SGO [press release].