title: Efficacy and tolerability of a low-dose, 2-week administration of sunitinib followed by a week rest (2/1 schedule) for metastatic renal cell carcinoma: a single center experience of six cases.
abstract: BACKGROUND
  Sunitinib, an oral multitarget tyrosine kinase inhibitor and standard first-line treatment for metastatic renal cell carcinoma (mRCC), is generally administered on a 6-week schedule (4 weeks on/2 weeks off). However, drug toxicity often leads to temporary treatment interruption, resulting in reduced treatment efficacy. In this report, we investigated whether sunitinib administration of at a dose of 25 mg/day in a 2-weeks-on/1-week-off cycle would reduce the incidence of drug-related side effects while maintaining drug efficacy.
  
  
  RESULTS
  A total of six patients with mRCC were orally administered sunitinib at a dose of 25 mg/day in a 2-weeks-on/1-week-off regimen until intolerable toxicities occurred. All enrolled patients were assessed for toxicity and response. The median treatment period was 24 months (range, 9-40 months). Objective responses were as follows: disease stabilization of >6 months was achieved in all patients. The most important toxicities were neutropenia, fatigue, and proteinuria, but all were controlled.
  
  
  CONCLUSIONS
  Oral sunitinib at 25 mg/day in a 2-weeks-on/1-week-off regimen to Japanese patients can avoid drug-related toxicities while achieving the same dose intensity as a 6-week schedule. Because these data were derived from a small number of patients, future prospective studies of modified sunitinib administration schedules are warranted.
authors.affiliation: Department of Urology, Ome Municipal General Hospital, 4-16-5 Higashiome, Ome, Tokyo, Japan. katsuhiromakino@gmail.com.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Makino
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoda
authors.forename: Junzo
authors.initials: J
authors.lastname: Tomoishi
authors.forename: Haruki
authors.initials: H
authors.lastname: Kume
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007211:Indoles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011758:Pyrroles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000077210:Sunitinib
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib