Retrospective study and outcome of 307 cats with feline infectious peritonitis treated with legally sourced veterinary compounded preparations of remdesivir and GS-441524 (2020–2022)

Abstract

Objectives Feline infectious peritonitis (FIP) is a serious disease that arises due to feline coronavirus infection. The nucleoside analogues remdesivir and GS-441524 can be effective in its treatment, but most studies have used unregulated products of unknown composition. The aim of the present study was to describe the treatment of FIP using legally sourced veterinary-prescribed regulated veterinary compounded products containing known amounts of remdesivir (injectable) or GS-441524 (oral tablets). Methods Cats were recruited via email advice services, product sales contacts and study publicity. Cats were excluded if they were deemed unlikely to have FIP, were not treated exclusively with the veterinary compounded products, or if there was a lack of cat and/or treatment (including response) data. Extensive cat and treatment data were collected. Results Among the 307 cats recruited, the predominant type of FIP was most commonly abdominal effusive (49.5%) and then neurological (14.3%). Three treatment protocols were used; remdesivir alone (33.9%), remdesivir followed by GS-441524 (55.7%) and GS-441524 alone (10.4%). The median (range) initial treatment period duration and longest follow-up time point after starting treatment were 84 (1–330) days and 248 (1–814) days, respectively. The most common side effect was injection pain (in 47.8% of those given subcutaneous remdesivir). Of the 307 cats, 33 (10.8%) relapsed, 15 (45.5%) during and 18 (54.5%) after the initial treatment period. At the longest follow-up time point after completion of the initial treatment period, 84.4% of cats were alive. The cats achieving a complete response within 30 days of starting treatment were significantly more likely to be alive at the end of the initial treatment period than those cats that did not. Conclusions and relevance Legally sourced remdesivir and GS-441524 products, either alone or used sequentially, were very effective in the treatment of FIP in this group of cats. Variable protocols precluded statistical comparison of treatment regimens.

Abdominal ultrasonographic findings of cats with feline infectious peritonitis: an update

“…Two cats in this study received a novel antiviral therapy 8,9,12,13,20 and follow-up US showed partial to complete resolution of changes, suggesting that US may be a valuable tool in assessing response to treatment with this trial drug. Persistent US changes despite curative treatment with antiviral therapy have been documented in cats with FIP.…”

“…Persistent US changes despite curative treatment with antiviral therapy have been documented in cats with FIP. 9,12 Hence, a better understanding of FIP lesions that are detectable with ultrasound pretreatment is beneficial.…”

“…Historically considered a fatal disease, recent research has revealed efficacy of new antivirals in FIP treatment, making an early diagnosis even more critical. [7][8][9][10][11][12] Immunohistochemistry (IHC) for the FCoV antigen in affected tissues is considered the gold standard for the diagnosis of FIP. 7 In the absence of a definitive diagnosis, background, clinical signs, routine laboratory tests and molecular analyses can be combined to establish a high index of suspicion of FIP.…”

“…Historically considered a fatal disease, recent research has revealed efficacy of new antivirals in FIP treatment, making an early diagnosis even more critical. 7 –12…”

Emergence and spread of feline infectious peritonitis due to a highly pathogenic canine/feline recombinant coronavirus

“…This is indicative of high viral loads, but must be validated through quantification. Furthermore, a relatively high percent (Supplementary Table 4) of confirmed cases in Cyprus was presented with neurological signs (28%), which is double of what would be expected with classical FIP (14%) 27 . This may be due to increased awareness of presentation or be inherent to FCoV-23 neurotropism; however, further investigation is required.…”