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Why we created a 20mg/ml GS-441524 formulation?

Updated: Jan 18

We formulated a 20mg/ml concentration of

GS-441524 for the treatment of Feline Infectious Peritonitis, an industry first, for 3 reasons.

Reason 1: RELAPSE

It is a heartbreaking experience when a cat appears to have recovered from FIP, only to relapse weeks or months later. Unfortunately, relapse can occur in any treatment. In some cases, the use of low-quality GS or incorrect dosage can be the cause of relapse. However, there are also genetic and environmental factors that are beyond our control.

Even cats treated with our brand can experience relapse. We have treated thousands of cats, and our calculations show that the percentage of cats who relapse when following our treatment recommendations is 2.6%. [Read: How we have treated 1000 cats with FIP and what we have learned.]

However, we often receive inquiries from cat owners whose cats have relapsed after being treated with another brand. They may have lost faith in their former brand or want to try a different one to prevent future relapses. Many of the cats that come to us for help after relapse were initially treated with Oral GS-441524. [Read: Are Oral Pills Effective Against Feline Infectious Peritonitis (FIP)?]

Reason 2: Larger Cats

Despite treating over 1000 cats, we continue to be surprised by the size and weight of modern cats that have been raised on formulated diets. It is not uncommon for us to receive photos and videos of cats weighing 5, 6, or even 7 kilograms. For cats that are larger in size, administering injections using 15mg/ml can be a challenging and painful process.

Let's take a 5 kg cat diagnosed with neurological FIP as an example:

  • Using 15mg/ml, one injection requires 3.33ml

  • Using 20mg/ml, one injection requires 2.50ml

Based on the calculations provided earlier, it is evident that the 20mg/ml formulation necessitates injecting 0.83ml less per dosage. To those who are not well-versed in subcutaneous injections, injecting 0.83ml of fluid into an average-sized cat can be quite a substantial amount.

Reason 3: Neurological FIP Cases

The time frame for treating cats with neurological symptoms is rapidly closing. The FIP virus is progressing and reaching the point of biological shutdown. Cats with neurological symptoms require a high dosage of GS-441524 to halt further virus replication and begin the healing process. Typically, cats with neurological symptoms require the longest treatment and the highest dosage. We highly recommend administering two injections per day during the initial stage of treatment, spaced 12 hours apart, with each injection utilizing 50% of the recommended daily dosage. Through our experiments, we have found that this method ensures a consistent and sufficient amount of GS-441524 is delivered directly to the cat's bloodstream, effectively halting FIPV replication.

We greatly hope that our new 20mg/ml formulation will increase the success rate of FIP treatment while making the treatment a lot easier for cats and its caregivers.

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Keywords: Feline infectious peritonitis

  1. FIP symptoms

  2. FIP treatment

  3. FIP diagnosis

  4. FIP causes

  5. FIP vaccine

  6. FIP research

  7. FIP in kittens

  8. FIP in older cats

  9. FIP survival rate

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