title: Improved overall survival in dendritic cell vaccination-induced immunoreactive subgroup of advanced melanoma patients.
abstract: BACKGROUND
  We present our experience of therapeutic vaccination using dendritic cells (DC) pulsed with autologous tumor antigens in patients with advanced melanoma.
  
  
  METHODS
  Twenty-one pretreated advanced melanoma patients were vaccinated with autologous DC pulsed with 100 microg/ml of autologous-tumor-lysate (ATL) or -homogenate (ATH) and 50 microg/ml of keyhole limpet hemocyanin (KLH). The first 8 patients were treated subcutaneously or intradermally with immature-DC (iDC) (range 4.5-82 x 10(6)) and the remaining 13 intradermally with in vitro matured DC (mDC) (range 1.2-26 x 10(6)). Subcutaneous interleukin-2 (3 x 10(6) IU) was administered from days 3 to 7 of each treatment cycle.
  
  
  RESULTS
  Three of the 8 iDC patients obtained stabilizations (SD), each of 6 months' duration. The 13 mDC patients showed 1 complete response (8 months), 1 partial response (3 months), 2 mixed responses (6 and 12 months) and 3 SD (9, 7+, and 3+ months). Overall responses (OR) were observed in 4/21 (19%) patients, or 4/13 (30.7%) considering mDC treatment only. 10/21 (47.6%) patients showed non progressive disease (NPD), with 7/13 (53.8%) cases of NPD for mDC-treated patients. No major toxicities were observed. The positive delayed-type hypersensitivity (DTH) test to ATL/ATH and/or KLH correlated with increased overall survival (OS). Median OS was 24 months (range 3-45) for the 10 DTH-positive (1 iDC and 9 mDC) and 5 months (range 3-14) for the 11 DTH-negative patients (P < 0.001). The in vitro evaluation of gamma IFN-secreting T-cells in 10 patients showed good correlation with both DTH (75%) and clinical outcome (70%).
  
  
  CONCLUSIONS
  Vaccination using DC pulsed with ATL/ATH and KLH in advanced melanoma patients is well tolerated and can induce a clinical response, especially when mDC are used. Successful immunization, verified by positive DTH, leads to longer survival.
authors.affiliation: Department of Medical Oncology, Morgagni-Pierantoni Hospital, Via Forlanini 34, 47100 Forlì, Italy. r.ridolfi@ausl.fo.it
authors.forename: Ruggero
authors.initials: R
authors.lastname: Ridolfi
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Petrini
authors.forename: Laura
authors.initials: L
authors.lastname: Fiammenghi
authors.forename: Monica
authors.initials: M
authors.lastname: Stefanelli
authors.forename: Laura
authors.initials: L
authors.lastname: Ridolfi
authors.forename: Michela
authors.initials: M
authors.lastname: Ballardini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Migliori
authors.forename: Angela
authors.initials: A
authors.lastname: Riccobon