The FDA has awarded orphan drug designation to Tenaya Therapeutics Inc.'s gene therapy product candidate, TN-401, for the treatment of arrhythmogenic right ventricular cardiomyopathy (ARVC). TN-401 is an adeno-associated virus (AAV)-based gene therapy being developed for the treatment of genetic ARVC caused by plakophilin-2 (PKP2) gene mutations.