Clinical and pharmacokinetic study of sunitinib and docetaxel in women with advanced breast cancer

Background: This exploratory study examined the pharmacokinetics, safety, and antitumor activity of sunitinib plus docetaxel in patients with HER-2-negative advanced breast cancer. Patients and methods: Patients with HER-2-negative disease who had received prior adjuvant anthracycline-based therapy received docetaxel (75 mg/m²) on day 1 of each 3-week cycle followed by sunitinib (37.5 mg/day for 2 weeks on Schedule 2/1) starting on day 2 (day 3 on cycle 2). Results: Twenty-two patients were enrolled. No clinically significant drug-drug interactions were observed. The most common non-hematologic AE (any grade) was fatigue/asthenia. Grade 4 neutropenia occurred in 20/22 patients (91%; n = 7 had neutropenic fever). The safety profile was similar to each agent given individually. 14/19 (73.7%) evaluable patients had a PR and 5/19 (26.3%) had SD. Conclusions: Sunitinib plus docetaxel on Schedule 2/1 did not result in any clinically significant drug-drug interactions. This combination was manageable and exhibited antitumor activity.