ICON7: Bevacizumab reduced deaths by 36% in advanced ovarian cancer

2011 ASCO Annual Meeting

CHICAGO – Interim results from the phase-3 ICON7 trial showed that some women with stage III/stage IV ovarian cancer who underwent surgery were more likely to survive if they were assigned to bevacizumab along with chemotherapy compared with standard therapy.

A planned subgroup analysis showed that bevacizumab (Avastin, Genentech) was associated with a 36% reduced risk for death in women with stage III disease who had more than 1 cm of tumor after surgery and all stage IV patients who had surgery.

“Based on this interim analysis of 53% of the number of events needed for final analysis of OS, we see there is an overall trend toward improvement in OS with bevacizumab,” said Gunnar Kristensen, MD, PhD, senior consultant in the department for gynecologic oncology, at Norwegian Radium Hospital in Oslo. “This treatment effect is greater in high-risk patients, which might be clinically relevant.”

Kristensen discussed the findings at a press conference during the 2011 ASCO Annual Meeting.

From December 2006 to February 2009, women with newly diagnosed high-risk or advanced epithelial ovarian, primary peritoneal or fallopian tube cancer were randomly assigned to six cycles of chemotherapy alone (n=464) or the same chemotherapy concurrently with 7.5 mg/kg bevacizumab followed by bevacizumab alone (n=470) for 12 months.

In an exploratory subgroup analysis of patients with poor prognosis, researchers observed 109 deaths in the control group vs. 79 deaths in the bevacizumab group (HR=0.64; 95%CI=0.48-0.85).

“For this group there is a very clear gain in OS,” Kristensen said. “The median gain was about eight months.”

There were 377 deaths recorded at a median follow-up of 28 months, 200 in the control group vs. 177 in the bevacizumab group (HR=0.84, 95%CI=0.69-1.03). That represents a 15% decreased risk for death, but that outcome was not statistically significant. Final results are expected in 2013.

Kristensen also presented updated PFS results data. Those results showed that bevacizumab was associated with a median 2.4 month increase in 12-month PFS overall. – by Jason Harris

For more information:

• Kristensen G. #LBA5006. Presented at: 2011 ASCO Annual Meeting; Chicago; June 3-7, 2011.

Disclosure: Dr. Kristensen reported serving in a consultant or advisory role with Roche.

Again we see the ability of antiangiogenic therapies to delay the progression of ovarian cancer, this time in the first-line setting. The consistent results of the OCEANS and ICON7 trials, in addition to the previously reported GOG 218 trial and the already documented efficacy of bevacizumab as a single agent in ovarian cancer, all lend support to a potentially important role for bevacizumab as the first biologic agent to be used in this disease.

- Andrew Seidman, MD
Attending Physician, Breast Cancer Medicine Service,
Memorial Sloan-Kettering Cancer Center

Disclosure: Dr. Seidman reported serving in a consultant or advisory role with Enzon and Wyeth, receiving honoraria from Abraxis BioScience, Genentech and Genomic Health; a receiving research funding from Abraxis BioScience.

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