title: Sunitinib treatment for patients with advanced clear-cell renal-cell carcinoma after progression on sorafenib.
abstract: BACKGROUND
  Sorafenib and sunitinib are tyrosine kinase inhibitors with largely overlapping specificities, approved for the treatment of metastatic renal-cell carcinoma (RCC). It was unclear whether the similarities of the two drugs would lead to complete cross-resistance, or whether sequential application would be efficacious.
  
  
  METHODS
  Patients with metastatic RCC and progression on sorafenib treatment were treated with repeated cycles of sunitinib, 50 mg for 4 weeks, followed by a 2-week break. Response (Response Evaluation Criteria in Solid Tumors, RECIST) was assessed every second cycle.
  
  
  RESULTS
  A total of 22 patients with progression on sorafenib were accrued. Initially, sorafenib treatment was efficacious in all patients, with 7 showing partial response (PR) and 15 stable disease (SD), and subsequent disease progression. With 4 PRs (18%) and 12 SD (55%) a disease control rate of 73% was achieved. The median progression-free survival (PFS) on sunitinib was 21.5 weeks; median overall survival (OS) was not reached. Estimated 1-year PFS and OS were 31 and 60%, respectively. There was no apparent relationship between response to sorafenib and outcome on sunitinib.
  
  
  CONCLUSIONS
  In our cohort of patients with RCC and progression after initial efficacy of sorafenib, the efficacy data of second-line sunitinib were close to published results of first-line treatment, suggesting limited clinically relevant cross-resistance.
authors.affiliation: Department of Medicine III (Hematology, Oncology and Transfusion Medicine), Charité, Campus Benjamin Franklin, Berlin, Germany. kaja.zimmermann@charite.de
authors.forename: Kaja
authors.initials: K
authors.lastname: Zimmermann
authors.forename: Alexander
authors.initials: A
authors.lastname: Schmittel
authors.forename: Ursula
authors.initials: U
authors.lastname: Steiner
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Asemissen
authors.forename: Maren
authors.initials: M
authors.lastname: Knoedler
authors.forename: Eckhard
authors.initials: E
authors.lastname: Thiel
authors.forename: Kurt
authors.initials: K
authors.lastname: Miller
authors.forename: Ulrich
authors.initials: U
authors.lastname: Keilholz