Joshua J. Todd, Tokunbor A. Lawal, Irene C. Chrismer, Angela Kokkinis, Christopher Grunseich, Minal S. Jain, Melissa R. Waite, Victoria Biancavilla, Shavonne Pocock, Kia Brooks, Christopher J. Mendoza, Gina Norato, Ken Cheung, Willa Riekhof, Pooja Varma, Claudia Colina-Prisco, Magalie Emile-Backer, Katherine G. Meilleur, Andrew R. Marks, Yael Webb, Eugene E. Marcantonio, A. Reghan Foley, Carsten G. Bönnemann, and Payam Mohassela
RYR1-related myopathies (RYR1-RM) are caused by pathogenic variants in the RYR1 gene which encodes the type 1 ryanodine receptor (RyR1). RyR1 is the sarcoplasmic reticulum (SR) calcium release channel that mediates excitation-contraction coupling in skeletal muscle. RyR1 sub-conductance, SR calcium leak, reduced RyR1 expression, and oxidative stress often contribute to RYR1-RM pathogenesis. Loss of RyR1-calstabin1 association, SR calcium leak, and increased RyR1 open probability were observed in 17 RYR1-RM patient skeletal muscle biopsies and improved following ex vivo treatment with Rycal compounds. Thus, we initiated a first-in-patient trial of Rycal S48168 (ARM210) in ambulatory adults with genetically confirmed RYR1-RM.
