title: Phase II study of lapatinib in combination with vinorelbine, as first or second-line therapy in women with HER2 overexpressing metastatic breast cancer.
abstract: BACKGROUND
  Lapatinib in combination with capecitabine is approved for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress the human epidermal growth factor receptor 2 (HER2) and who have received prior therapy including an anthracycline, a taxane, and trastuzumab. Based on our phase I trial, we conducted a single arm, multicenter phase II study of lapatinib in combination with vinorelbine.
  
  
  METHODS
  Women with HER2-positive advanced breast cancer, who had received up to one prior regimen for metastatic disease, were eligible. Prior trastuzumab was allowed. Patients received daily lapatinib 1500 mg orally and vinorelbine 20 mg/m(2) intravenously on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was overall response rate (ORR).
  
  
  RESULTS
  Forty-four patients received the combination treatment, including 48% as second-line therapy. The ORR was 41% (95% confidence interval [CI] 26-55%), including 9% with a complete response. Median progression-free survival was 24.1 weeks (95% CI 17-37 weeks) and median duration of response was 32 weeks (95% CI 18-42 weeks). Nearly 80% of patients did not require a dose reduction in lapatinib, although most patients required one dose reduction of vinorelbine secondary to neutropenia. The most common toxicities were grade 1 and 2 diarrhea, nausea, fatigue and rash, and grade 3 and 4 neutropenia. One case of grade 3 asymptomatic decreased left ventricular ejection fraction event was reported.
  
  
  CONCLUSIONS
  The combination of lapatinib and vinorelbine was active, feasible and well tolerated in patients with HER2-positive advanced breast cancer.
authors.affiliation: Division of Hematology/Oncology, UC Davis Comprehensive Cancer Center, 4501 X Street, Suite 3016, Sacramento, CA 95817 USA.
authors.forename: Helen Kent
authors.initials: HK
authors.lastname: Chew
authors.affiliation: The West Clinic, Memphis, TN USA.
authors.forename: Lee
authors.initials: L
authors.lastname: Schwartzberg
authors.affiliation: Cancer Specialists of North Florida, Jacksonville, FL USA.
authors.forename: Suprith
authors.initials: S
authors.lastname: Badarinath
authors.affiliation: Cone Health Cancer Center, Greensboro, NC USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Rubin
authors.affiliation: Jackson Oncology Associates, Jackson, MS USA.
authors.forename: Grace
authors.initials: G
authors.lastname: Shumaker
authors.affiliation: Northwest Alabama Cancer Center, Florence, AL USA.
authors.forename: James
authors.initials: J
authors.lastname: Daugherty
authors.affiliation: GlaxoSmithKline, Collegeville, PA USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: DeSilvio
authors.affiliation: GlaxoSmithKline, Collegeville, PA USA.
authors.forename: Janine
authors.initials: J
authors.lastname: Mahoney
keywords: HER2; Lapatinib; Metastatic breast cancer; Vinorelbine