MDL-206

MDL-206 is a preclinical-stage gene therapy candidate developed by Modalis Therapeutics for the treatment of Angelman Syndrome, a rare neurogenetic disorder. The therapy utilizes the proprietary CRISPR-GNDM (CRISPR-Guide Nucleotide-Directed Modulation) platform, which employs a catalytically inactive Cas9 (dCas9) protein fused to an effector domain to perform epigenome editing without inducing double-strand DNA breaks. MDL-206 is specifically designed to reactivate the silenced paternal copy of the *UBE3A* gene in neurons, thereby restoring the production of the UBE3A protein to compensate for the loss-of-function maternal allele that characterizes the disorder. Originally part of a joint research program with Astellas Pharma, the program is now being advanced independently as part of Modalis's in-house pipeline.