Bevacizumab Maintenance Reduces Disease Progression Risk in Ovarian Cancer
Chicago, IL—The “big news” in metastatic ovarian cancer presented at ASCO 2011 involved the investigational poly (ADP-ribose) polymerase (PARP) inhibitor olaparib, which prolonged progression-free survival (PFS) by nearly 4 months versus placebo. The results of this study were reported in the June issue of VBCC.
In addition, 2 other studies reported in the meeting show that maintenance therapy with bevacizumab (Avastin) reduced the risk of disease progression, both in the metastatic setting and in early-stage disease.
The OCEANS Trial
The phase 3 randomized, doubleblind, multicenter OCEANS trial evaluated the use of bevacizumab plus carboplatin (Paraplatin) and gemcitabine (Gemzar) versus chemotherapy alone in 484 women with recurrent platinum-sensitive ovarian cancer.
After 6 cycles, those receiving the bevacizumab-containing regimen continued to receive bevacizumab alone as maintenance therapy until disease progression.
Patients in the bevacizumab arm had a median PFS of 12.4 months compared with 8.4 months with chemotherapy alone (P <.001), representing a 52% reduction in the risk of progression, said Carol Aghajanian, MD, Memorial Sloan-Kettering Cancer Center, New York.
“OCEANS is a positive study. We met our primary end point,” Dr Aghajanian said at a press briefing. “The safety data are also reassuring and consistent with the known side effect profile. We believe this regimen should be considered a new option for recurrent platinum-sensitive ovarian cancer.”
Updated A second analysis presented at the meeting was the updated results from the ICON7 trial of 1528 women with early- or advanced-stage ovarian cancerwho received carboplatin and paclitaxel (Taxol), with or without bevacizumab, for 6 cycles. In the experimental arm, at the end of the 6 cycles, bevacizumabmonotherapy was continued as maintenance therapy for a total of 12 cycles. In this study, the PFS was 19.8 months in the bevacizumab arm and 17.4 months with chemotherapy alone—a 13% reduction in progression risk (P = .039).
In addition, a 15% reduction in risk of deathwas also seen in this study, but this was not statistically significant, reported Gunnar Kristensen, MD, Norwegian Radium Hospital in Oslo, Norway.
Subgroup analysis showed that patients deemed at highest risk for disease recurrence—those with suboptimally debulked stage III cancer—had even better outcomes, experiencing a significant 36% reduction in the risk of death (P = .002). Median overall survival was 36.6 months in the bevacizumab arm compared with 28.8 months in the control arm.
Dr Kristensen noted that the study revealed a treatment effect that is greater in high-risk patients, “and this may be of clinical relevance.”