Interferon-omega for FIP?

A study was conducted to determine whether feline interferon-omega (FeIFN-W) prolongs survival time and increases quality of life in cats with feline infectious peritonitis (FIP). FIP status in the 37 cats included in the study was confirmed by histology or immunostaining of feline coronavirus (FCoV) antigen in effusion, tissue macrophages, or both. The cats were then randomly selected for treatment with either FeIFN-W or placebo. Cats (n = 21) in the interferon group received 106 U/kg (0.1 ml/kg) FeIFN-W SC Q 24 H for 8 days. After day 8, cats received 106 U/kg FeIFN-W once a week for a total of 1 year or until euthanasia. All cats received adjunctive treatment with glucocorticoids and antibiotics and passive immunization with Feliserin (Germany). Cats also received nutrition management and fluid therapy as needed. The median survival time of cats in the FeIFN-W group was 9 days; median survival time in the placebo group was 8 days. Therefore, no effect of FeIFN-W on survival time or quality of life could be demonstrated in this study. Reasons for the lack of efficacy of FeIFN-W are unknown. It is possible that the FeIFN-W did not reach tissue concentrations sufficient to exhibit an antiviral effect, or treatment intervals may have been too long. Treatment may also have been initiated too late. Ideally, therapy should start at the time of the mutation, before the mutated virus replicates and invades different tissues. However, because viral mutation precedes clinical signs and a diagnosis is not possible until severe immune-mediated reactions have occurred, the time point of mutation could not be detected.

Effect of feline interferon-omega on the survival time and quality of life of cats with feline infectious peritonitis. Ritz S, Egberink H, Hartmann K. J VET INTERN MED 21:1193-1197, 2007.