CureFIP™ GS-441524 Injectable 30mg/ml
 
The Standard Concentration — CureFIP™'s Most Widely Used FIP Injectable
 
What This Product Is
CureFIP™ GS-441524 30mg/ml is the most widely used formulation in the CureFIP™ injectable range. It contains GS-441524 — a nucleoside analogue antiviral — at a concentration optimised for the standard FIP treatment protocol in adult cats weighing 2.5 to 5 kg. It covers all primary FIP presentations without neurological involvement: wet (effusive) form, dry (non-effusive) form, and ocular form.
 
The 30mg/ml concentration is not the standard because it is the middle option in our range. It is the standard because it produces the most clinically practical injection volume for the weight range that represents the majority of FIP cases — adult domestic cats between 2.5 and 5 kg.
 
Why 30mg/ml Is the Clinical Default
FIP treatment dosing is determined by mg of GS-441524 per kg of body weight. Across the 2.5–5 kg adult cat weight range, the 30mg/ml concentration simultaneously satisfies three requirements that determine clinical practicality:
 
The injection volume is large enough to be measured accurately with a standard syringe — eliminating the measurement error risk associated with the very small volumes produced by 40mg/ml in this weight range.
 
The injection volume is small enough to be administered comfortably in a single subcutaneous injection — avoiding the excessive volumes produced by 20mg/ml in this weight range.
The concentration is consistent enough to support precise daily dose adjustment as a cat's weight changes during treatment — which is common as cats in recovery gain condition.
 
This is why 30mg/ml accounts for the majority of CureFIP™ injectable treatment courses across all markets.
 
Indicated Cases
This formulation is appropriate for:
Adult cats weighing 2.5 to 5 kg at treatment initiation
Wet (effusive) FIP — abdominal effusion, pleural effusion
Dry (non-effusive) FIP — granulomatous lesions, organ involvement
Ocular FIP — uveitis, aqueous flare, chorioretinitis
First-line treatment following new FIP diagnosis
Cats selecting GS-441524 monotherapy rather than dual antiviral protocol
 
This Formulation Is Not the First Choice For
Cats weighing under 2.5 kg — the 20mg/ml formulation is indicated for dosing precision
Cats weighing over 5 kg — the 40mg/ml formulation avoids excessive injection volumes
Cats presenting with neurological FIP — consider dual antiviral therapy with EIDD-1931 (CureFIP™ Dual Antiviral Oral Capsules) or the 30mg/ml + B12 formulation for additional systemic support
Cases with confirmed GS-441524 resistance or relapse — the 40mg/ml formulation and dual antiviral protocol are indicated
 
Clinical Background
GS-441524 is a nucleoside analogue antiviral that inhibits feline coronavirus (FCoV/FIPV) replication. Following cellular uptake and phosphorylation to its active triphosphate metabolite (GS-443902), it acts as a substrate for the viral RNA-dependent RNA polymerase (RdRp). The 1'-cyano substitution causes steric clash following incorporation into nascent RNA chains, producing delayed chain termination and halting viral RNA synthesis.
 
First described as effective against FIP in Pedersen et al. (2019, Nature), GS-441524 has since been evaluated in multiple prospective randomised controlled trials and retrospective cohort studies. Published remission rates in completed treatment cohorts consistently range from 80 to 94% across wet, dry, and ocular presentations. The 30mg/ml concentration has the longest clinical track record of any concentration in the CureFIP™ range due to its position as the standard treatment formulation.
 
Concentration Selection Guide
Concentration
Primary Indication
20mg/ml
Cats under 2.5 kg · Kittens · Precision low-volume dosing
30mg/ml (this product)
Cats 2.5–5 kg · All standard FIP presentations · First-line
40mg/ml
Cats over 5 kg · High-dose protocols · Resistance · Relapse
30mg/ml + B12
Cats 2.5–5 kg with anaemia, neurological symptoms, or appetite loss
 
Dual Antiviral Option
If your cat has previously been treated with GS-441524 and relapsed, or if your veterinarian suspects early resistance, consider CureFIP™ Dual Antiviral Oral Capsules (GS-441524 + EIDD-1931). Combining two antivirals with distinct mechanisms of action — RdRp chain termination and lethal mutagenesis — creates a dual barrier against viral resistance that monotherapy cannot provide.
 
Administration
Administer subcutaneously once daily. Dose is calculated in mg of GS-441524 per kg of body weight. Standard treatment duration is 84 consecutive days without interruption. Weigh your cat weekly and recalculate dose if weight changes by more than 10%. Use the dosing calculator to determine the correct injection volume for your cat's current weight.
 
Most cats show observable treatment response within the first 7 days — appetite improvement and fever reduction are the earliest indicators. Blood parameter normalisation typically follows over weeks 2–4. If no clinical response is observed within 7 days, contact our clinical support team.