FDA Approves First Drug for Managing Ventricular Hypertrophy in Cats with HCM

Felycin-CA1 (sirolimus delayed-release tablets) is the first FDA-approved drug for managing ventricular hypertrophy in cats with subclinical hypertrophic cardiomyopathy (HCM), a condition affecting up to 1 in 7 cats. The drug, available nationwide, is specifically designed for cats and is the only FDA-conditionally approved therapy for HCM in cats. Feline HCM is a leading cause of mortality in adult cats, and subclinical HCM refers to cases with ventricular wall thickening but no clinical signs.

Felycin-CA1, a delayed-release formulation of sirolimus, has been granted conditional approval by the FDA for the management of ventricular hypertrophy in cats with subclinical hypertrophic cardiomyopathy (HCM). This approval marks a significant milestone in veterinary medicine, as HCM is a leading cause of mortality in adult cats, affecting up to 1 in 7 cats [1].

The drug, developed by PBI-Gordon Companies, Inc., is specifically designed for cats and is the only FDA-conditionally approved therapy for HCM in cats. Felycin-CA1 is available nationwide through licensed veterinarians and is set to fundamentally change the HCM treatment landscape, a market severely underserved by effective therapies [1].

The RAPACAT study, conducted to obtain conditional approval, demonstrated the safety and effectiveness of Felycin-CA1 in managing HCM in cats. The HALT study is currently enrolling cats and aims to pursue full new animal drug approval for the drug [1].

Tenaya Therapeutics, Inc., a clinical-stage biotech company, has also made progress in developing gene therapies for HCM. The company has completed enrollment in both dose cohorts of its MyPEAK-1 Phase 1b/2 clinical trial for TN-201, a gene therapy targeting HCM. The company reported favorable tolerability profiles for both TN-201 and TN-401, another gene therapy targeting arrhythmogenic right ventricular cardiomyopathy (ARVC) [2].

The prevalence of HCM in the British Shorthair breed is particularly high, with field studies indicating that British Shorthairs have an HCM prevalence 2–3 times higher than the general cat population. Regular cardiology examinations, including echocardiography and NT-proBNP screening, are recommended to detect HCM early and protect British Shorthairs' hearts [3].

References:
[1] https://www.businesswire.com/news/home/20250730624005/en/Felycin-CA1-Sirolimus-Delayed-Release-Tablets-is-the-First-and-Only-Drug-FDA-Approved-for-the-Management-of-Ventricular-Hypertrophy-in-Cats-with-Subclinical-Hypertrophic-Cardiomyopathy-HCM-A-Condition-Affecting-as-Many-as-One-in-Seven-Cats
[2] https://za.investing.com/news/company-news/tenaya-completes-enrollment-in-both-dose-cohorts-for-hcm-gene-therapy-93CH-3811044
[3] https://zoomveteriner.com/en/british-shorthair-heart-screening/