If your cat is diagnosed with HCM, don't panic

Felycin-CA1 is a once-weekly oral medication. It should be given just after a meal.

Felycin-CA1 is recommended as a lifelong medication for the management of ventricular hypertrophy due to subclinical HCM. There have been no studies following the progression of HCM after discontinuation of this product.

The best way to know how your cat is doing is to monitor the heart’s structure and function with an echocardiogram. If your veterinarian orders one before your cat begins taking Felycin-CA1, they’ll have a baseline to compare as they track your cat’s response to Felycin-CA1 (such as watching ventricular wall thickness). Without the baseline echocardiogram, your veterinarian would need to rely on watching your cat’s symptoms (clinical signs), which is subjective and potentially unreliable since HCM is known for showing few to no warning signs in the early stages. For reference, the cats in Felycin-CA1’s RAPACAT study had baseline echocardiograms performed before starting the medication, then again at 60 days and 180 days. Typically, the recommendation for monitoring with echocardiograms is every 6 months. Your veterinarian will recommend a monitoring schedule that’s right for your cat.

What you can watch for at home
While your vet handles the technical monitoring, you can watch for:

• Changes in resting breathing rate (counting breaths while they’re asleep or deeply relaxed – normal is less than 30-35 breaths per minute)
• Any labored or open-mouth breathing
• Less activity or hiding more than usual
• Changes in appetite or eating habits

If you notice any of these signs, call your veterinarian to discuss.

Receiving FDA conditional approval means that Felycin-CA1 has met strict requirements for safety, as well as demonstrated a reasonable expectation of effectiveness. Evidence for its effectiveness will continue to be collected for up to five years, ultimately working towards full approval by the FDA.

Missing a dose of Felycin-CA1 will not cause any immediate problems for your cat. If you happen to miss a dose, wait until the next week to give the regularly scheduled dose so you can stay on a consistent schedule.

Other than more regular vet checkups, yes—they can live a normal life. The goal is for cats with subclinical HCM taking Felycin-CA1 to stay symptom-free for as long as possible. Starting Felycin-CA1 in the subclinical stage of the disease gives the best chance of delaying progression of the disease.

One to two months after starting Felycin-CA1, your cat should get another full physical exam and lab work. These should be repeated every 6-12 months thereafter. If at any point your veterinarian sees liver enzyme elevations more than twice the upper limit of normal, then Felycin-CA1 should be discontinued. Felycin-CA1 should also be discontinued in the event a cat is diagnosed with diabetes mellitus.

Felycin-CA1 tablets are covered in a special coating that ensures the medication is absorbed at the correct rate. The tablets cannot be crushed, split or chewed because this would compromise the coating. Affecting this coating would not only change the absorption profile but also risk human exposure to the active ingredient sirolimus (rapamycin).

The label indication for Felycin-CA1 is to manage ventricular hypertrophy in cats with subclinical HCM. No studies have been completed to support efficacy in patients with clinical and late-stage cardiac disease. In addition, cats in congestive heart failure may need to start other medications, and no studies have been done to test for using those medications along with Felycin-CA1. Therefore, continued treatment with Felycin-CA1 in a patient with congestive heart failure would be considered off-label, which is not recommended.