SAN ANTONIO — Far and away the largest-ever analysis of osteonecrosis of the jaw occurring in women receiving the antiangiogenesis agent bevacizumab for advanced breast cancer indicates the incidence is less than 1%, even in patients receiving bisphosphonates.
This analysis involved more than 3,500 bevacizumab-treated women with locally recurrent or metastatic breast cancer prospectively followed in large clinical trials. As such, it provides a more accurate risk estimate than the rather alarming 16% incidence reported by Greek investigators in 116 patients on a bisphosphonate plus bevacizumab or another antiangiogenesis agent, sunitinib (Oncology 2009;76:209–11), Dr. Valentina Guarneri noted at the San Antonio Breast Cancer Symposium.
The 3,560 women in this analysis were participants in the open-label ATHENA study or the randomized RIBBON-1 or AVADO trials. In the randomized trials, the incidence of osteonecrosis of the jaw (ONJ) was 0.3% in patients on bevacizumab and 0 with placebo during follow-up of 10–19 months. In ATHENA, the incidence was 0.4% during 13 months of follow-up of more than 2,200 women on bevacizumab.
In ATHENA, the incidence of ONJ was 2.4% in patients who had been exposed to bisphosphonates and 0 in those who had not. In the two randomized trials, the rate was 0.9% in patients who had been on a bisphosphonate, compared with 0.2% in those who had not, according to Dr. Guarneri of the University of Modena and Reggio Emilia (Italy). The study was funded by F. Hoffmann-La Roche.