Sunitinib plus paclitaxel well tolerated in advanced breast cancer
MedWire News: Sunitinib given in combination with paclitaxel to patients with advanced breast cancer is well tolerated, with evidence of anti-tumor activity and no drug-drug interactions, data from an exploratory study show.
Sunitinib, an angiogenesis inhibitor, has shown single-agent activity in patients with previously treated metastatic breast cancer (MBC), note Mark Kozloff (Ingalls Memorial Hospital, Harvey, Illinois, USA) and colleagues.
In the present study, Kozloff and team investigated the safety, efficacy, and pharmacokinetics of sunitinib and paclitaxel when given in combination, to 22 patients with locally advanced or MBC.
Patients received oral sunitinib 25 mg/day (with escalation to 37.5 mg/day as tolerated) on a continuous daily dosing schedule, and paclitaxel 90 mg/m2 on days 1, 8, and 15 of each 28-day cycle.
The patients received a median of six cycles of sunitinib and five cycles of paclitaxel. Eighteen (82%) discontinued treatment during the first year, mainly due to disease progression. Only one patient discontinued treatment due to an adverse event, a chronic leg ulcer.
The researchers found that the safety profile of combined sunitinib and paclitaxel was similar to that of each agent given as monotherapy. The most frequent adverse events of any grade were fatigue/weakness (77%), a distorted sense of taste (68%), and diarrhea (64%). Grade 3 adverse events included neutropenia (43%), fatigue/weakness (27%), neuropathy (18%), and diarrhea (14%).
Phamacokinetic analyses revealed no clinically significant drug-drug interactions between sunitinib and paclitaxel.
Among 18 patients with measurable disease at baseline, two (11.1%) complete responses and five (27.8%) partial responses were reported, resulting in an overall objective response rate of 38.9%. Of note, clinical responses were observed in three (33.3%) of nine patients with triple-negative receptor status.
"These data indicate that sunitinib and paclitaxel in combination are well tolerated in patients with locally advanced or MBC," conclude Kolzoff and co-authors in the Annals of Oncology.
They add: "Sunitinib continues to be evaluated as a potential treatment of advanced breast cancer in combination with chemotherapy, and studies with sunitinib are continuing in the neoadjuvant breast cancer setting."
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By Laura Dean