Acadia Pharmaceuticals announced the termination of development for ACP-101, an intranasal therapy targeting hyperphagia in Prader-Willi syndrome patients, following a phase III trial that failed to meet its primary endpoint. The study showed no statistically significant improvement over placebo in mitigating insatiable appetite symptoms, a critical concern for this rare genetic disorder. This decision impacts the therapeutic landscape for Prader-Willi, narrowing options and potentially benefiting competitors with approved treatments.