SAN ANTONIO—Multi-targeted TKI inhibitors are gaining traction in the treatment of advanced breast cancer, although results from four different trials do show varying degrees of efficacy. In multiple presentations at SABCS 2009, researchers made their respective cases for adding sorafenib (Nexavar), motesanib (MONET1), and sunitinib (Sutent) into the treatment mix.
With the exception of one agent, the overall results were promising, but oncologists need to bear in mind that although these similar drugs have broad activity, the jury is still out on how to administer them optimally.
Sorafenib: TIES and SOLTI
Early results were presented for sorafenib in combination with either capecitabine (Xeloda) or paclitaxel from a collaborative group-sponsored randomized double-blind phase IIb trials program called TIES (Trials to Investigate the Efficacy of Sorafenib in Breast Cancer), which is evaluating the TKI in patients with advanced HER2-negative breast cancer.
Jose Baselga, MD, chair of medical oncology at Vall d'Hebron University Hospital in Barcelona, Spain, offered updated results from the SOLTI-0701 trial (see page 22), reporting that sorafenib plus capecitabine continued to show favorable results over capecitabine alone (see Table on page 3).
An exploratory subgroup analysis found consistent benefit for the combination regardless of disease-free interval, number of metastatic sites, and country of treatment. “The subgroup analyses confirm the robustness of the progression-free survival [PFS] benefit. Sorafenib plus capecitabine was favored across all pre-specified and exploratory subgroup analyses,” Dr. Baselga said (abstract 45).
While hand-foot skin reactions were common in the study with sorafenib, Dr. Baselga said, “we are working on ways to reduce this with careful monitoring. We are confident we can improve this by being on top of it from the beginning.”