CHICAGO—More support for bevacizumab in the treatment of ovarian cancer emerged at the 2011 annual meeting of the American Society of Clinical Oncology, with studies showing the drug prolongs the time to disease progression, both in the metastatic and primary disease settings.
OCEANS, a phase 3 multicenter randomized trial, evaluated the addition of bevacizumab to 6 cycles of carboplatin and gemcitabine in 484 patients with recurrent ovarian cancer who were platinum-sensitive (ie, recurrence >6 months of platinum-based treatment). Patients in the bevacizumab arm continued to receive bevacizumab as maintenance therapy until disease progression.
Patients in the bevacizumab arm demonstrated a median progression-free survival (PFS) of 12.4 months, compared with 8.4 months with chemotherapy alone (P <.0001), amounting to a 52% reduction in the risk of progression, reported Carol Aghajanian, MD, chief of the Gynecologic Medical Oncology Service, Memorial Sloan-Kettering Cancer Center, New York.
“OCEANS is a positive study. We met our primary end point,” she 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.”
Also presented were updated results from the ICON7 trial of 1528 women with early or advanced-stage ovarian cancer who received carboplatin and paclitaxel, with or without bevacizumab, for 6 cycles; in the experimental arm, single-agent bevacizumab was continued as maintenance therapy for a total of 12 cycles.
PFS was 19.8 months in the bevacizumab arm and 17.4 months with chemotherapy alone, for a 13% reduction in risk of progression (P = .039). There was a 15% reduction in risk of death, but this was not statistically significant, reported Gunnar Kristensen, MD, PhD, senior consultant in the Department for Gynecologic Oncology, Norwegian Radium Hospital in Oslo, Norway.
Subgroup analysis showed that patients deemed at highest risk for recurrence—those with suboptimally debulked stage III cancer—had even better outcomes, experiencing a statistically significant 36% reduction in the risk of death (P = .002). Median overall survival was 28.8 months in the control arm but reached 36.6 months in the bevacizumab arm.
Kristensen noted that this is an interim analysis, and an overall survival difference may still emerge for the whole population. Meanwhile, the study revealed a treatment effect that is greater in high-risk patients, he added, “and this may be of clinical relevance.”