EM-221

EM-221 is a novel, orally active small molecule that acts as a highly selective phosphodiesterase 10A (PDE10A) inhibitor. It is being developed by EuMentis Therapeutics, in-licensed from Mochida Pharmaceutical. The drug is designed to modulate dopaminergic brain circuits—specifically the dopamine D2 pathway in the striatum—which are implicated in movement disorders such as Tourette syndrome. By targeting PDE10A with high specificity to the brain’s movement centers, EM-221 aims to reduce unwanted movements and vocalizations associated with Tourette syndrome while minimizing side effects commonly seen with antipsychotic drugs. Its mechanism of action offers potential advantages over existing therapies due to improved safety and tolerability profiles[1][3][4][5][7].