2024-04-16
FIP TREATMENT WITH ORAL FORMULATIONS OF GS-441524
The initial field testing of GS-441524 for FIP treatment involved subcutaneous injection. This route of administration was based on prior pharmacokinetic (PK) studies done on laboratory cats. Intravenous and subcutaneous routes of injection yielded similar high blood levels that were sustained at virus inhibitory concentrations for over 24 hours. Oral administration was also found to provide blood levels, peaking at 2 hours, but reaching only about 40% peak levels of subcutaneous and intravenous routes (Pedersen NC, unpublished data, 2018). However, dogs which have a longer intestinal tract evolved for omnivorous diets, can absorb up to 85% of GS441524 by the oral route [1, 5]. Dogs have often been used as surrogates for humans in oral absorption studies, so oral absorption in humans is also likely to be higher than in cats.