Bevacizumab Delays Progression, May Extend Survival in Ovarian Cancer
Two phase 3 international clinical studies show that initiating therapy with bevacizumab in combination with standard chemotherapy extends progression-free survival (PFS) in women with advanced ovarian cancer, and women at high risk for disease progression may live longer with the addition of bevacizumab to standard therapy (Burger RA, et al. N Engl J Med. 2011;365:2473-2483; Perren TJ, et al. N Engl J Med. 2011;365:2484-2496).
In the Gynecologic Oncology Group (GOG)-0218 study, 1873 women with newly diagnosed stage III or stage IV ovarian cancer who had undergone debulking surgery were randomized to 1 of 3 treatments for 22 cycles of 3 weeks each: standard chemotherapy (carboplatin plus paclitaxel, cycles 1-6) followed by placebo (cycles 7-22); standard chemotherapy plus bevacizumab 15 mg/kg followed by placebo; or standard chemotherapy plus bevacizumab 15 mg/kg, followed by an additional course of bevacizumab 15 mg/kg. The primary end point was PFS.
After a median follow-up of 17.4 months, the median PFS was 14.1 months in those who received bevacizumab for the entire study period
versus 11.2 months in those receiving bevacizumab only in the initial cycles, and 10.3 months in those who received only standard chemotherapy. The difference in overall survival (OS) between the groups was not significant.
Hypertension (grade ≥2) was the only adverse event occurring significantly more often in patients receiving bevacizumab for the entire study (22.9%) or in the initial cycles (16.5%) than in those receiving standard chemotherapy (7.2%).
The second study, the International Collaboration on Ovarian Neoplasms (ICON7), was similar in design to GOG-0218, but only 91% of the 1528 women had stage III or IV ovarian cancer; 9% had high-risk early-stage disease; and 30% were at high risk for disease progression.
Patients were randomized to standard chemotherapy every 3 weeks for 6 cycles or to standard chemotherapy plus bevacizumab 7.5 mg/kg every 3 weeks for 5 or 6 cycles and continuation with bevacizumab for an additional 12 cycles or until disease progression occurred.
At a median follow-up of 19.4 months, median PFS was 19.0 months in the bevacizumab group and 17.3 months in the chemotherapy group. In patients at high risk for progression, PFS was 15.9 months with bevacizumab versus 10.3 months with standard chemotherapy; at 42 months, OS was 36.6 months versus 28.8, respectively.
Adverse events were similar to those in the GOG-0218 study.