CHICAGO—Bevacizumab in combination with chemotherapy followed by maintenance bevacizumab monotherapy improves progression-free survival (PFS) over chemotherapy alone in the treatment of advanced ovarian cancers, said Robert A. Burger, MD at the 46th American Society of Clinical Oncology annual meeting.
Advances in the treatment of ovarian cancer have been limited during the past decade, said Burger. Standard therapy for ovarian cancer had been surgery and relatively toxic chemotherapy (carboplatin and paclitaxel). The new finding means that bevacizumab with chemotherapy followed by continuation of bevacizumab alone should be considered as one standard option in the frontline treatment of advanced ovarian cancer, he said.
He presented the results from a three-arm study of 1873 chemotherapy-naïve patients with advanced epithelial ovarian, primary peritoneal, or fallopian tube cancer who had already had surgery to debulk the tumor. The patients were randomized to either:
· Six cycles of chemotherapy (carboplatin and paclitaxel) followed by placebo for an additional 10 months
· Six cycles of chemotherapy plus five cycles of bevacizumab given concurrently, followed by placebo maintenance
· Six cycles of chemotherapy plus five cycles of bevacizumab given concurrently, followed by continuation of bevacizumab alone.
After a median follow-up of 17.4 months, the median PFS for women who received chemotherapy alone was 10.3 months. In women treated with chemotherapy/bevacizumab with continuation of bevacizumab, the median PFS was 14.1 months, representing a 28% reduction in the risk of cancer progression or death, and a 39% improvement in the likelihood of living longer without disease progression.
All patient subgroups based on age, disease stage, and performance status had improvement in PFS with concomitant/continuation of bevacizumab compared with chemotherapy alone or chemotherapy only with concomitant bevacizumab, said Burger, director, Women’s Cancer Center, Fox Chase Cancer Center, Philadelphia.
Women who received chemotherapy and bevacizumab but without continuation of bevacizumab did not show an increase in PFS compared with chemotherapy alone.
No differences emerged in overall survival between the three arms, but the survival data are not yet mature, he said.
Adverse events with bevacizumab were similar to previous studies of bevacizumab. Women who received maintenance bevacizumab in addition to their chemotherapy had a higher rate of neutropenia than those treated with chemotherapy alone. Grade 4 or higher neutropenia occurred in 63.3% of those receiving maintenance bevacizumab in addition to chemotherapy, compared with 57.7% of those receiving chemotherapy alone.
Grade 3 or higher pain, grade 3 or higher hypertension, and grade 2 or higher gastrointestinal events were also more common with maintenance bevacizumab/chemotherapy compared with chemotherapy alone.
Elizabeth A. Eisenhauer, MD, of the National Cancer Institute of Canada Clinical Trials Group, offered that changing the standard of care for advanced ovarian cancer based on the findings of this study would be premature. “A PFS gain of only 3.8 months may not be meaningful to patients,” she said. The mature overall survival data are needed before the full effect of bevacizumab can be placed into a clinical context.