Purpose: The aim of this Phase II study was to assess the efficacy and safety of vandetanib in combination with docetaxel in patients with pretreated advanced breast cancer.
Methods: The primary study objective was to compare the number of progression events in patients receiving once-daily oral vandetanib (100 mg) in combination with docetaxel (100 mg/m(2) iv every 21 days) versus placebo plus docetaxel. Sixty-four patients were randomized to receive study treatment (n = 35, vandetanib; n = 29, placebo).
Results: A slightly greater number of patients had experienced a progression event by the data cut-off in the vandetanib group (24 [69%]) compared with the placebo group (18 [62%]); HR = 1.19, two-sided 80% CI: 0.79-1.81; two-sided P = 0.59), suggesting that the addition of vandetanib to docetaxel did not affect the risk of disease progression compared with placebo plus docetaxel. The safety and tolerability profile of the combination therapy reflected those of both drugs as monotherapy agents.
Conclusions: In patients with advanced breast cancer, vandetanib plus docetaxel was generally well tolerated. Clinical benefit was not different to that observed with placebo plus docetaxel. However, due to the small patient number it was not possible to yield robust results, further research is required to identify predictive factors for patient selection.