title: Phase I Study of Triweekly Nab-Paclitaxel Combined with S-1 in Patients with HER2-negative Metastatic Breast Cancer.
abstract: We conducted a phase I study to determine the maximum tolerated dose (MTD) and recommended dose (RD) of triweekly nanoparticle albumin-bound paclitaxel (nab-paclitaxel) and S-1 combination therapy in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC).
  
  
  
  This study was carried out with a 3+3 dose escalation design; patients with HER2-negative MBC received nab-paclitaxel at 180-260 mg/m2on day 1 and S-1 at 65-80 mg/m2daily on days 1-14, repeated every 3 weeks.
  
  
  
  The MTD was level 3 (260 mg/m2nab-paclitaxel with 80 mg/m2S-1) and the RD was level 2 (260 mg/m2nab-paclitaxel with 65 mg/m2S-1). Dose-limiting toxicity was observed in two patients at level 3, who had grade 4 neutropenia and grade 3 myalgia, respectively.
  
  
  
  The response rate was 66.7%. The clinical benefit rate was 77.8%. Our study shows the efficacy and the feasibility of this combination therapy.
authors.affiliation: Department of Endocrine and Breast Surgery, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan ksak@koto.kpu-m.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sakaguchi
authors.affiliation: Department of Endocrine and Breast Surgery, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Nakatsukasa
authors.affiliation: Department of Endocrine and Breast Surgery, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Taguchi
mesh_terms: D000368:Aged; D000068196:Albumin-Bound Paclitaxel / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004338:Drug Combinations; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010094:Oxonic Acid / Q000008:administration & dosage; D005641:Tegafur / Q000008:administration & dosage
chemical_list: D000068196:Albumin-Bound Paclitaxel; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid
keywords: Breast cancer; HER2-negative; Nab-paclitaxel; S-1; metastatic; phase I study