THURSDAY, March 25, 2021 (HealthDay News) -- Women with advanced ovarian cancer often face grim statistics, with less than half surviving for five years after their diagnosis. However, a new study suggests that so-called "maintenance therapy" with a targeted cancer drug may add years to some patients' lives.
In findings described by some experts as "remarkable," the study showed that women with advanced ovarian cancer linked to the BRCA gene were much more likely to be alive with no signs of their cancer coming back in five years if they receive Lynparza (olaparib), a targeted cancer therapy known as a PARP inhibitor.
This class of drugs blocks an enzyme called PARP that cancer cells need to repair damage to their genetic material, and blocking it causes cancer cells to die. There are two other PARP inhibitors approved to treat ovarian cancer, Zejula (niraparib) and Rubraca (rucaparib).
PARP inhibitors are particularly effective against cancers linked to BRCA genes. Often thought of as the breast cancer genes, BRCA1 and BRCA2are responsible for roughly 25% of ovarian cancer cases.
The new study provides five-year follow-up data from a clinical trial of women with BRCA-positive advanced ovarian cancer who received Lynparza for two years after their initial treatment ended.
Happily, the survival benefits lasted five years out regardless of how aggressive the cancers were, said study author Dr. William Bradley, a gynecologic oncologist at Froedtert Health and Medical College of Wisconsin in Milwaukee.
It's still too early to use the word cure, but that may be where this is headed, he added. "Maintenance therapy with Lynparza really should be considered standard of care for BRCA-positive advanced ovarian cancer," Bradley said.
The study included 391 women with a BRCA mutation and advanced ovarian cancer who completed chemotherapy; 260 received Lynparza and 131 received a placebo. When compared with women on the placebo pill, more than twice as many women on Lynparza were still alive with no progression of their cancer five years after the study began. The trial was funded by Lynparza maker AstraZeneca.
"This is really good news," Bradley said. "Women enjoyed the benefit for the next three years when off therapy."
Calling the new results "quite remarkable," Dr. Konstantin Zakashansky, director of gynecologic oncology at Mount Sinai West in New York City, said that the new findings may well be akin to a cure for these women.
"Even after five years, there is quite a significant benefit," said Zakashansky, who wasn't part of the study. "We have never seen anything like this before with ovarian cancer."
PARP inhibitors do have their share of side effects, including risk for blood abnormalities that can leave women more prone to infection or fatigue, but the follow-up data showed that these do not get worse with time, researchers said. "The safety signal did not progress or become ominous," Bradley said.
These women will now be followed indefinitely, he added.
The new findings suggest that maintenance therapy with Lynparza has a lasting impact for women with BRCA-positive advanced ovarian cancer, and time will answer all remaining questions, said Dr. Deborah Armstrong, a professor of oncology at Johns Hopkins Kimmel Cancer Center in Baltimore. She was not involved in the new study.
"Is it possible that two years of therapy with this drug is nipping cancer cells in the bud or are they just quieted down and will come back later?" Armstrong asked.
Another point is that the new drug may be cost-prohibitive for some women, she said. "It is extremely expensive, costing $10,000 to $12,000 a month, and even people with really good insurance have high copays."
The findings were presented at the Society of Gynecologic Oncology's virtual annual meeting, held March 19-25. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
The National Ovarian Cancer Coalition offers more on ovarian cancer treatment options.
SOURCES: William Bradley, MD, gynecologic oncologist, Froedtert Health and Medical College of Wisconsin, Milwaukee; Deborah K. Armstrong, MD, professor, oncology, professor, gynecology and obstetrics, Johns Hopkins Kimmel Cancer Center, Baltimore; Konstantin Zakashansky, MD, director, gynecologic oncology, Mount Sinai West, and associate professor, obstetrics and gynecology, Icahn School of Medicine, Mount Sinai, New York City; Society of Gynecologic Oncology, virtual annual meeting; March 19-25, 2021