Bevacizumab Plus Novel Monoclonal Antibody in Metastatic Kidney Cancer
Adding the monoclonal antibody TRC105, which targets the glycoprotein endoglin, to bevacizumab did not improve progression-free survival in patients with refractory metastatic renal cell carcinoma, based on the findings of a study published in Cancer by Tanya B. Dorff, MD, of the University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, and colleagues. However, patients with non–clear cell kidney cancer who received bevacizumab alone or in combination with TRC105 had stable disease.
A total of 59 patients with metastatic renal cell carcinoma took part in the study: 28 were treated with bevacizumab alone and 31 were treated with bevacizumab plus TRC105. All of them had previously received one to four lines of therapy, including vascular endothelial growth factor–targeted agents.
One patient on each treatment arm had a confirmed partial response. Progression-free survival for those treated with bevacizumab alone was 4.6 months, compared with 2.8 months for those on the combination treatment.
In patients who had baseline serum transforming growth factor beta (TGF-b) levels below a median of 10.6 ng/mL, progression-free survival was more than twice as long as in those with levels at or above the median (5.6 vs. 2.1 months). Thus, further study of the TGF-b pathway expression as a potential predictive marker in advanced renal cell carcinoma may be warranted.