Adjuvant immunotherapy of feline fibrosarcoma with recombinant feline interferon-omega.
BACKGROUND
Recombinant feline interferon-omega (rFeIFN-omega) was tested as a treatment option for cats with fibrosarcoma to assess safety and feasibility.


OBJECTIVE
Treatment with rFeIFN-omega in cats with fibrosarcoma is safe and feasible.


METHODS
Twenty domestic cats.


METHODS
In an open-labeled uncontrolled clinical trial 12 injections of 1 x 10(6) U/kg rFeIFN-omega were administered over a 5-week period: the 1st through 4th injections were given intratumorally, and the 5th through 12th injections were administered subcutaneously at the tumor excision site. Wide surgical excision of the tumors was carried out after the 4th injection and before the 5th injection of rFeIFN-omega. A Common Terminology Criteria for Adverse Events (CTCAE) analysis was conducted. Flow cytometry of fibrosarcoma cells after incubation with rFeIFN-omega and recombinant feline interferon-gamma was performed to assess the biological effect of rFeIFN-omega.


RESULTS
Changes in blood cell count, increases in serum aspartate-amino-transferase activity, serum bilirubin concentration, serum creatinine and serum electrolyte concentrations, weight loss, anorexia, increased body temperature, and reduced general condition were observed but were mostly minor (grade 1 and 2) and self limiting. Eosinophilia (P = .025), neutropenia (P = .021), and weight loss (P < .001) were statistically correlated with rFeIFN-omega-treatment (analysis of parameters before treatment and after 3 injections of rFeIFN-omega). Flow cytometry of 5 unrelated feline fibrosarcoma cell lines showed increased expression of major histocompatibility complex (MHC) class I molecules (P = .026) in response to in vitro incubation with rFeIFN-omega, whereas expression of MHC class II molecules was not affected significantly.


CONCLUSIONS
RFeIFN-omega for the treatment of feline fibrosarcoma is safe, well tolerated, and can be easily performed in practice. To assess the efficacy of the treatment, it should be tested in a placebo-controlled trial.
Hampel
Verena
V
Department of Veterinary Internal Medicine, Veterinary Faculty, LMU Munich, Munich, Germany. verena.hampel@web.de
Schwarz
Bianca
B
Kempf
Christine
C
Köstlin
Roberto
R
Schillinger
Ulrike
U
Küchenhoff
Helmut
H
Fenske
Nora
N
Brill
Thomas
T
Hirschberger
Johannes
J
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000818:Animals; D002371:Cat Diseases / Q000188:drug therapy*; D002415:Cats; D005354:Fibrosarcoma / Q000188:drug therapy / Q000662:veterinary*; D006649:Histocompatibility Antigens; D007370:Interferon Type I / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000627:therapeutic use; D011994:Recombinant Proteins
D000276:Adjuvants, Immunologic; D006649:Histocompatibility Antigens; D007370:Interferon Type I; D011994:Recombinant Proteins; C063743:interferon omega 1; D007371:Interferon-gamma