Oral Interferon for FIV

Recombinant feline interferon-omega (rFeIFN-ω), an immune-modulator drug licensed for use in Europe, Australia, and some Asian countries, is frequently used in the management of FIV and FeLV. The compound is thought to act on innate immunity. A recent study demonstrated clinical improvement and reduction of concurrent viral excretion in naturally retrovirus-infected cats in catteries. Some reports suggested that rFeIFN-ω may affect acute-phase proteins (APP) and serum levels of APP may be indirect indicators of innate immune system stimulation. APPs and concurrent viral excretion in naturally infected FIV-positive cats were measured for an oral rFeIFN-ω protocol, in comparison with a licensed SC protocol. FIV-positive cats (n = 11) were treated with oral rFeIFN-ω and results were compared with data previously obtained from 7 FIV-positive cats treated with the licensed SC protocol. Results indicated that rFeIFN-ω induced significant clinical improvement of treated FIV-infected cats regardless of route of administration. Overall clinical scores were slightly higher in the oral group as compared with the SC group, but not significantly. While the reason is unclear, it appeared the oral rFeIFN-ω protocol caused significant clinical improvement but did not change concurrent viral excretion and variation of APP. Oral rFeIFN-ω may be an option for treatment of FIV-infected cats as a follow-up after the licensed protocol.

Global Commentary

This European study suggested that oral rFeIFN-ω may be useful in treating FIV-positive cats and would be easier to administer and potentially less expensive than SC injections. Although not licensed for oral use in the U.S., Virbagen Omega (Virbac, UK) has been investigated in various viral disorders, including gingivostomatitis of cats and canine parvovirus.^1,2 The compound may prove to be invaluable in the improvement of innate immunity in select populations.—Heather Troyer, DVM, DABVP, CVA

Source

Oral recombinant feline interferon-omega as an alternative immune modulation therapy in FIV positive cats: Clinical and laboratory evaluation. Gil S, Leal RO, McGahie D, et al. RES VET SCI 96:79-85, 2014.

1. Comparative efficacy of a recombinant feline interferon omega in refractory cases of calicivirus-positive cats with caudal stomatitis: A randomised, multi-centre, controlled, double-blind study in 39 cats. Hennet PR, Camy GA, McGahie DM, Albouy MV. J Feline Med Surg 13:577-587, 2011.2. Immunological effects of recombinant feline interferon-omega (KT-80) administration in the dog. Kuwabara M, Nariai Y, Horiuchi Y, et al. Microbiol Immunol 50:637-641, 2006.

This capsule is part of the WSAVA Global Edition of Clinician's Brief.