Drug developers big and small are pursuing a solution for the curse of psychosis that occurs along with the already tragic diagnosis of Alzheimer’s disease, an affliction known as ADP.

Drug developer stocks strengthened further through September and October, with the BioWorld Drug Developers Index (BDDI) rising from a 7.69% gain at the end of August, to 24.91% through the third quarter and 28.96% at October’s close. The BDDI outperformed both the Nasdaq Biotechnology Index and the Dow Jones Industrial Average, which finished October up 24.49% and 11.8%, respectively.

After a phase III stumble, Acadia Pharmaceuticals Inc. will drop development of ACP-101, intranasal carbetocin, to treat hyperphagia in patients with the rare genetic disorder Prader-Willi syndrome. Top-line data from the 12-week, double-blind, randomized phase III study missed its primary endpoint by not producing a statistically significant improvement over placebo.

Multiple datasets are due to roll out soon in the Prader-Willi syndrome (PWS) space, where contenders are trying varied mechanisms of action to tackle the rare genetic disorder characterized by insatiable hunger, or hyperphagia. In the mix are Aardvark Therapeutics Inc., Acadia Pharmaceuticals Inc., Rhythm Pharmaceuticals Inc. and Soleno Therapeutics Inc.

At the Alzheimer's Association International Conference (AAIC) 2025, researchers from Acadia Pharmaceuticals Inc. have presented novel results on the assessment of the pharmacologic and pharmacokinetic (PK) properties and nonclinical safety of ACP-204.

The BioWorld Drug Developers Index (BDDI) rebounded in the second quarter, ending the first half (H1) of 2025 up 1.23% after being down 7.36% at the end of March and 5.52% at April’s close. The BDDI continued to track just below the Dow Jones Industrial Average, which gained 3.64% in H1, and outperformed the Nasdaq Biotechnology Index, which ended June down 1.92%.

The BioWorld Neurological Diseases Index continued its downward slide into 2025, with 15 of the 20 component stocks posting losses. After dipping into negative territory in late February, the index dropped 15.99% by the end of March and closed May down 22.34%.

Pimavanserin is a 5-HT2A inverse agonist that is FDA approved for treating Parkinson’s disease psychosis. Acadia Pharmaceuticals Inc. searched for a compound that relies on pimavanserin but with an improved profile, including shorter half-life and reduced QT prolongation risk, which led to the identification of ACP-204.